Fishes

16 pages, 2726 KiB

Open AccessArticle

Molecular Characterization and Expression Response of Ghrelin, GLP-1 and PYY to Fasting, Dietary Lipid, and Fatty Acids in Silver Pomfret (Pampus argenteus)

by Lei Zhang, Peng Shi, Lin Zhang, Yajun Wang, Jilin Xu, Xiaojun Yan and Kai Liao

Fishes 2023, 8(3), 170; https://doi.org/10.3390/fishes8030170 - 22 Mar 2023

Cited by 1 | Viewed by 2356

Abstract

Ghrelin, glucagon-like peptide-1 (GLP-1), and peptide YY (PYY) are potent hormones mediating food intake according to the nutritional status in fish. However, limited information is available on these genes and their expression in response to nutrition in silver pomfret (Pampus argenteus [...] Read more.

Ghrelin, glucagon-like peptide-1 (GLP-1), and peptide YY (PYY) are potent hormones mediating food intake according to the nutritional status in fish. However, limited information is available on these genes and their expression in response to nutrition in silver pomfret (Pampus argenteus). A comparison analysis revealed that ghrelin and GLP-1 were relatively conserved in marine fish. PYYa and PYYb shared a low identity and were clustered to different PYY branches. Ghrelin, pyya, and pyyb mRNAs were highly expressed in the brain, while glp-1 was highly expressed in the gills and liver. The ghrelin mRNA expression was relatively high an hour post-feeding and decreased after 3 to 72 h of fasting. The glp-1 mRNA expression was increased after 6 to 24 h of fasting. The pyya mRNA expression was increased after 72 h of fasting, while the pyyb expression remained stable during fasting. The diet with 14% lipid promoted the expressions of glp-1, pyya, and pyyb, but inhibited the ghrelin expression. The ghrelin expression in the intestine was increased after palmitic acid, oleic acid (OA), linoleic acid (LA), α-linolenic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) incubation. OA decreased the expression of glp-1 and increased the expression of pyya. The expression of pyyb was downregulated by LA, DHA, and EPA. These results suggest the importance of ghrelin, glp-1, and pyy in coordinating food intake in response to fasting, dietary lipid concentration, and fatty acids in silver pomfret. Full article

(This article belongs to the Section Physiology and Biochemistry)

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Figure 1
Multiple amino acid sequence alignment of (A) ghrelin, (B) GLP-1, (C) PYYa and PYYb. Amino acids that are blacked indicate that amino acids in that column are identical across all species. Residues that are conserved in more than half of the listed peptides are shadowed. GenBank accession numbers: (A) SI (Silver pomfret) ghrelin; YA (Ya-fish) ghrelin (AEZ36050.1); CR (Crucian carp) ghrelin (ADP55075.1); CA (Grass carp) ghrelin (AFI98391.1); ZE (Zebrafish) ghrelin (ACJ76435.1); PA (Pacific bluefin tuna) ghrelin (BAM34457); LA (Largemouth bass) ghrelin (ACJ13547); EU (European seabass) ghrelin (ABG49130); MO (Mouse) ghrelin (AAI32231.1); HU (Human) ghrelin (ADM33790.1); (B) SI (Silver pomfret) GLP-1; MU (Mullet) GLP-1 (XP_047432601.1); BU (Blue tilapia) GLP-1 (XP_031584898.2); MA (Mandarin fish) GLP-1 (XP_044044264.1); HU (Humphead wrasse) GLP-1 (XP_041638161.1); SW (Swordfish) GLP-1 (XP_039997917.1); CL (Clownfish) GLP-1 (XP_023121936.1); BL (Bluefin tuna) GLP-1 (XP_042261152.1); ZE (Zebrafish) GLP-1 (NP_001258699.1); HM (Human) GLP-1 (NP_002045); (C) SI (Silver pomfret) PYYa; SI (Silver pomfret) PYYb; PE (European Perch) PYYa (XP_039682240.1); ZE (Zebrafish) PYYa (Q9I8P2.1); GO (Goldfish) PYY (ACJ03593.1); GR (Grass carp) PYY (AFE89419.1); MO (Mouse) PYY (AAH10821.1); HU (Human) PYY (P10082.3); FR (African clawed frog) PYY (XP_018092481.2); LA (Large yellow croaker) PYY (XP_019126422.1); SE (Senegalese sole) PYYa (AML27066.1), and CH (Chicken) PYY (P29203.1). Full article ">Figure 2
Phylogenetic analysis of (A) ghrelin, (B) GLP-1, (C) PYYa and PYYb amino acid sequences. Scale bar indicates the substitution rate per residue. Numbers at nodes indicate the bootstrap value, as percentages, obtained for 1000 replicates. GenBank accession numbers: (A) Grass carp ghrelin (AFI98391.1); Ya-fish ghrelin (AEZ36050.1); Black sea bream ghrelin (AAV65508); Black tilapia ghrelin (BAC55160.1); Red Tilapia ghrelin (BAC65151.1); Channel catfish ghrelin (NP_001187244.1); Crucian carp ghrelin (ADP55075.1); Zebrafish ghrelin (ACJ76435.1); Mouse ghrelin (AAI32231.1); Human ghrelin (ADM33790.1); (B) Clownfish GLP-1 (XP_023121936.1); Coral reef fish GLP-1 (XP_022071913.1); Striped bass (XP_035533384.1); Bluefin tuna GLP-1 (XP_042261152.1); Mullet GLP-1 (XP_047432601.1); Blue tilapia GLP-1 (XP_031584898.2); Gilthead seabream GLP-1 (XP_030266058.1); Zebrafish GLP-1 (NP_001258699.1); Mouse GLP-1 (NP_001096638); Human GLP-1 (NP_002045); African clawed frog GLP-1 (NP_001079142.1); (C) Tilapia PYY (XP_003446444.1); Senegalese sole PYYa (AML27066.1); Zebrafish PYYa (AAF79942.1); Goldfish PYY (ACJ03593.1); African clawed frog PYY (XP_018092481.2); Human PYY (CAG46926.1); Mouse PYY (AAH10821.1); Chinese perch PYY (XP_044063373.1); Large yellow croaker PYY (XP_019126422.1), and Rainbow trout (PYY P69093.1). Full article ">Figure 3
Tissue distribution of (A) ghrelin, (B) glp-1, (C) pyya, and (D) pyyb of silver pomfret (Pampus argenteus). Bars with different letters represent significant differences between different tissues (p < 0.05). Full article ">Figure 4
Relative expression levels of (A) ghrelin, (B) glp-1, (C) pyya, and (D) pyyb mRNA of silver pomfret (Pampus argenteus) at different fasting times. Bars with different letters represent significant differences between different time points (p < 0.05). Full article ">Figure 5
Relative expression levels of ghrelin, glp-1, pyya, and pyyb in the intestine of silver pomfret (Pampus argenteus) fed diets with different fat contents. Asterisks represent significant differences between the 8% lipid diet groups and 14% lipid diet groups (* p < 0.05). Full article ">Figure 6
Relative expression levels of (A) ghrelin, (B) glp-1, (C) pyya, and (D) pyyb in the intestine of silver pomfret (Pampus argenteus) incubated with FAs. Asterisks represent significant differences between the control groups and FAs treatment groups (* p < 0.05). Full article ">

14 pages, 4557 KiB

Open AccessArticle

Diseased Fish Detection in the Underwater Environment Using an Improved YOLOV5 Network for Intensive Aquaculture

by Zhen Wang, Haolu Liu, Guangyue Zhang, Xiao Yang, Lingmei Wen and Wei Zhao

Fishes 2023, 8(3), 169; https://doi.org/10.3390/fishes8030169 - 21 Mar 2023

Cited by 16 | Viewed by 5198

Abstract

In intensive aquaculture, the real-time detection and monitoring of common infectious disease is an important basis for scientific fish epidemic prevention strategies that can effectively reduce fish mortality and economic loss. However, low-quality underwater images and low-identification targets present great challenges to diseased [...] Read more.

In intensive aquaculture, the real-time detection and monitoring of common infectious disease is an important basis for scientific fish epidemic prevention strategies that can effectively reduce fish mortality and economic loss. However, low-quality underwater images and low-identification targets present great challenges to diseased fish detection. To overcome these challenges, this paper proposes a diseased fish detection model, using an improved YOLOV5 network for aquaculture (DFYOLO). The specific implementation methods are as follows: (1) the C3 structure is used instead of the CSPNet structure of the YOLOV5 model to facilitate the industrial deployment of the algorithm; (2) all the 3 × 3 convolutional kernels in the backbone network are replaced by a convolutional kernel group consisting of parallel 3 × 3, 1 × 3 and 3 × 1 convolutional kernels; and (3) the convolutional block attention module is added to the YOLOV5 algorithm. Experimental results in a fishing ground showed that the DFYOLO is better than that of the original YOLOV5 network, and the average precision was improved from 94.52% to 99.38% (when the intersection over union is 0.5), for an increase of 4.86%. Therefore, the DFYOLO network can effectively detect diseased fish and is applicable in intensive aquaculture. Full article

(This article belongs to the Special Issue Current Research on Fish Tracking Technology)

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14 pages, 4322 KiB

Open AccessArticle

Uptake Routes and Biodistribution of Polystyrene Nanoplastics on Zebrafish Larvae and Toxic Effects on Development

by Martina Contino, Greta Ferruggia, Roberta Pecoraro, Elena Maria Scalisi, Gianfranco Cavallaro, Carmela Bonaccorso, Cosimo Gianluca Fortuna, Antonio Salvaggio, Fabiano Capparucci, Teresa Bottari and Maria Violetta Brundo

Fishes 2023, 8(3), 168; https://doi.org/10.3390/fishes8030168 - 20 Mar 2023

Cited by 13 | Viewed by 2621

Abstract

Polystyrene (PS) is the most widely used plastic polymer. It is mainly used to produce disposable products. Due to its resistance to degradation, PS can remain in the environment for a long time. Its mechanical, physical and biological actions determine the release of [...] Read more.

Polystyrene (PS) is the most widely used plastic polymer. It is mainly used to produce disposable products. Due to its resistance to degradation, PS can remain in the environment for a long time. Its mechanical, physical and biological actions determine the release of smaller fragments, which are able to penetrate organisms and accumulate in target organs. Fertilized Danio rerio eggs were exposed to concentrations of 10 and 20 mg/L of fluorescent, amino-modified polystyrene nanoplastics (nPS-NH₂) with diameters of 100 and 50 nm for 96h, according to OECD guidelines (2013). Uptake, biodistribution, toxicity, oxidative stress and apoptosis were evaluated; moreover, we carried out a simulation to study the interactions between nPS-NH₂ and defined regions of three receptors: STRA6, Adgrg6 and CNTN4/APLP2. We demonstrated that after being internalized, nPS-NH₂ could reach the head and bioaccumulate, especially in the eyes. Moreover, they could lead to oxidative stress and apoptosis in the several regions where they bioaccumulated due to their interaction with receptors. This study confirmed the danger of nanoplastic wastes released in the environment. Full article

(This article belongs to the Special Issue Zebrafish Pathology and Contaminant Pathological Effects)

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16 pages, 4824 KiB

Open AccessArticle

A New Conditionally Immortalized Nile Tilapia (Oreochromis niloticus) Heart Cell Line: Establishment and Functional Characterization as a Promising Tool for Tilapia Myocarditis Studies

by Yanghui Chen, Yuan Li, Dongneng Jiang, Defeng Zhang, Yu Huang, Jia Cai, Jichang Jian and Bei Wang

Fishes 2023, 8(3), 167; https://doi.org/10.3390/fishes8030167 - 18 Mar 2023

Cited by 1 | Viewed by 2107

Abstract

A new cell line named the tilapia heart cell line (TAH-11) was established from the heart of tilapia (Oreochromis niloticus) by enzymatic digestion and mechanical separation. The TAH-11 cell line has been stably subcultured for over 80 generations and resuscitated after [...] Read more.

A new cell line named the tilapia heart cell line (TAH-11) was established from the heart of tilapia (Oreochromis niloticus) by enzymatic digestion and mechanical separation. The TAH-11 cell line has been stably subcultured for over 80 generations and resuscitated after being frozen in liquid nitrogen for six months, with exuberant cell growth. The optimal culture condition of TAH-11 is L-15 medium supplemented with 10% fetal bovine serum at 25 °C. Sequencing of the mitochondrial 18S rRNAs confirmed that TAH-11 cells were derived from the tilapia. TAH-11 was also identified as a myocardial cell line based on the mRNA expression of the troponin I, α-actin and myoglobin genes. Simultaneously, TAH-11 could be successfully transfected with the GFP reporter gene, suggesting that the TAH-11 cell line could be used for exogenous gene expression in vitro. The TAH-11 cells showed susceptibility to CGSIV, which was demonstrated by the presence of a severe cytopathic effect, suggesting that the TAH-11 cell line is an ideal tool for studying host–virus interaction and potential vaccines. In addition, the expression of inflammatory factors in TAH-11 cells can be remarkably induced following Streptococcus agalactiae or Streptococcus iniae. The present data lays a foundation to further explore the mechanism of how Streptococcus spp. causes tilapia myocarditis. Full article

(This article belongs to the Section Welfare, Health and Disease)

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Graphical abstract

Graphical abstract
Full article ">Figure 1
Morphology of TAH-11 cell monolayers: (<bold>A</bold>) Passage 5; (<bold>B</bold>) Passage 20; (<bold>C</bold>) Passage 50; (<bold>D</bold>) Passage 70. Scale bar = 100 μm. Full article ">Figure 2
Growth kinetics of TAH-11cell line at Passage 50: (<bold>A</bold>) effects on cell growth of different medium at 25 °C; (<bold>B</bold>) effects of different concentrations of FBS in L-15 medium on cell growth at 25 °C; (<bold>C</bold>) effects of different culture temperatures on cell growth in L-15 medium containing 10% FBS. Full article ">Figure 3
Chromosome morphological features and frequency distribution of TAH-11-11 cells: (<bold>A</bold>) chromosome morphology of TAH-11 cells at Passage 50; (<bold>B</bold>) chromosome numbers were counted in colchicine-treated TAH-11 cells at Passage 50. Full article ">Figure 4
Multi-gene identification and detection of mycoplasma contamination. 18S rRNA amplification and mycoplasma testing (<bold>A</bold>) M: DL2000 DNA marker; Lanes 1: 18S rRNA (691 bp); Lanes 2: β-actin (115 bp); Lanes 3: myoglobin (112 bp); Lanes 4: troponin I (106 bp); Lanes 5: α-actin (184 bp); Lanes 6: Positive control; Lanes 7: Negative control; Lanes 8: TAH-11 cell supernatant; (<bold>B</bold>) sequencing results of the 18S rRNA amplification. Full article ">Figure 5
Expression of GFP reporter gene in TAH-11 cells and 293T cells: (<bold>A</bold>) TAH-11; (<bold>B</bold>) 293T cells. Scale bar = 75 μm. Full article ">Figure 6
Replication characteristic of CGSIV in TAH-11 cells: (<bold>A</bold>) CPE of TAH-11 cells infected with CGSIV at 12 h p.i; (<bold>B</bold>) CPE of TAH-11 cells infected with CGSIV at 24 h p.i; (<bold>C</bold>) CPE of TAH-11 cells infected with CGSIV at 36 h p.i; (<bold>D</bold>) CPE of TAH-11 cells infected with CGSIV at 48 h p.i; (<bold>E</bold>) L-15 with 10% FBS treatment; (<bold>F</bold>) L-15 without 10% FBS treatment. Scale bar = 100 μm. Full article ">Figure 7
Transmission electron micrograph of TA-11 infected by CGSIV: (<bold>A</bold>) areas indicated by red arrows containing virus particles; (<bold>B</bold>) transmission electron micrograph of TA-11-infected <italic>S. agalactiae</italic>. The areas indicated by blue arrows contain bacteria. Full article ">Figure 8
Adherence assay of <italic>S. agalactiae</italic>, <italic>S. iniae</italic> and <italic>E. coli</italic> (DH5α) to TAH-11 cells. Full article ">Figure 9
The expression patterns of immune-related gene expression (<italic>TNF-α</italic>, <italic>TGF-β</italic>, <italic>Caspase3</italic>, <italic>Caspase9</italic>, <italic>IL-8</italic>) at various points after <italic>S. agalactiae</italic> and <italic>S. iniae</italic> infection via qRT-PCR. Every value is presented as the mean and standard deviation; <italic>n</italic> = 3. The asterisks reveal a significant difference (<italic>p</italic> < 0.05). Full article ">

18 pages, 4176 KiB

Open AccessReview

Side Effects of Human Drug Use: An Overview of the Consequences of Eels’ Exposure to Cocaine

by Luigi Rosati, Ivana Caputo, Lillà Lionetti, Mayana Karoline Fontes, Camilo Dias Seabra Pereira and Anna Capaldo

Fishes 2023, 8(3), 166; https://doi.org/10.3390/fishes8030166 - 17 Mar 2023

Cited by 5 | Viewed by 3152

Abstract

The widespread use of drugs is a global problem which affects not only humans but also the environment around them, as research is showing the presence of these substances in different environmental matrices, like air, water, and soil. Above all, due to the [...] Read more.

The widespread use of drugs is a global problem which affects not only humans but also the environment around them, as research is showing the presence of these substances in different environmental matrices, like air, water, and soil. Above all, due to the remarkable pharmacological properties of drugs, it is discovered that organisms accidentally exposed to them, as aquatic organisms, undergo behavioral and physiological changes that can compromise their health, survival, and reproduction ability. In addition to this, we must consider the ability of some drugs to accumulate within these organisms, thus entering the food chain, and the possible interactions that drugs in water can establish with each other and with other possible pollutants, making the final effects on exposed organisms unpredictable. This article is an overview of the effects of one of these drugs, cocaine, one of the drugs commonly found in the aquatic environment, on European eel, an endangered species and known biomonitor of aquatic contamination. Full article

(This article belongs to the Special Issue Biology and Ecology of Eels)

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Light micrographs of the skin of Anguilla anguilla. Mallory staining. (A) Control and (B) exposed specimen. Cocaine exposure (B) caused the thickening and folding of the basal lamina (BL), the loss of apical vacuoles in club cells (C) and the decrease of mucous cells (M). Magnification: 400×. Full article ">Figure 2
Light micrographs of the intestine of Anguilla anguilla. Mallory staining. (A) Control and (B) exposed specimens. In control specimens, the intestinal mucosa (IM) showed signs of histolysis, whereas the muscular layers, inner circular layer (ICL) and outer longitudinal layer (OLL), showed sign of degeneration. In cocaine exposed specimens, the intestinal mucosa (IM) was well organized and had many folds, and the muscular layers appeared thick and well stained. Magnification: 100×. Full article ">Figure 3
Light micrographs of the gills of Anguilla anguilla. Mallory staining. (A) Control and (B) exposed specimens. In exposed specimens, the epithelium (E) appeared thickened, compared to control, and contained many mucous (M) cells, also present in the secondary lamellae (SL), which appeared partially fused. Magnification: 400×. Full article ">Figure 4
Light micrographs of the skeletal muscle of Anguilla anguilla. Mallory staining. (A) Control and (B) exposed specimens. In exposed specimens, the muscle fibres (M) showed less compactness and numerous breaks. Magnification: 400×. Full article ">Figure 5
Light micrographs of the liver of Anguilla anguilla. Mallory staining. (A) Control and (B) exposed specimens. In exposed specimens, the hepatocytes (HE) were devoid of lipids; necrotic areas (NA) and loss of parenchymal cells were evident. Magnification: 400×. Full article ">Figure 6
Light micrographs of the kidney of Anguilla anguilla. Mallory staining. (A) Control and (B) exposed specimens. In exposed specimens, the renal tubules (RT) showed nuclear alterations (*) and the structure of glomerulus (G) was disorganized. Magnification: 400×. Full article ">

12 pages, 4241 KiB

Open AccessCommunication

Complete Mitochondrial Genome and Phylogenetic Position of Chirolophis wui (Perciformes: Stichaeidae)

by Yong-Suk Lee, Maheshkumar Prakash Patil, Jong-Oh Kim, Yu-Jin Lee, Yong Bae Seo, Jin-Koo Kim, Kiran R. Mahale and Gun-Do Kim

Fishes 2023, 8(3), 165; https://doi.org/10.3390/fishes8030165 - 16 Mar 2023

Cited by 2 | Viewed by 1969

Abstract

The complete mitochondrial genome of Chirolophis wui (Wang and Wang, 1935) was sequenced using the Illumina platform. The genome sequence is 16,522 bp in length with 54% A+T content and contains 13 protein coding genes (PCGs), 22 transfer RNA genes (tRNAs), 2 ribosomal [...] Read more.

The complete mitochondrial genome of Chirolophis wui (Wang and Wang, 1935) was sequenced using the Illumina platform. The genome sequence is 16,522 bp in length with 54% A+T content and contains 13 protein coding genes (PCGs), 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs), and 1 control region (D-loop). The H-strand contains 28 genes (12 PCGs, 14 tRNAs, and 2 rRNAs), whereas the L-strand accommodates 9 genes (ND6 and 8 tRNAs). The nucleotide composition of the mitochondrial genome of C. wui is AT-biased, accounting for 54.0%, with an AT skew value of −0.0556 and a GC skew value of −0.2043. The majority of PCGs utilized the start codon, ATG, while only one gene, COI, utilized the alternative start codon, GTG. Of the 13 PCGs, 6 genes used the termination codon (TAA or TGA), whereas 7 genes used the incomplete termination codon (T or TA). Among the 22 tRNA genes, the tRNA-Leu and tRNA-Ser were found in duplicates. A phylogenetic tree was constructed using 10 complete mitochondrial genome sequences and indicated that C. wui has a very close relationship with C. japonicus and other species in the family Stichaeidae, with a high supporting bootstrap value. This study can provide valuable information for future evolutionary studies on C. wui and Stichaeidae. Full article

(This article belongs to the Section Taxonomy, Evolution, and Biogeography)

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Map showing the sampling location (Red spot). Map was downloaded from d-map (<a href="https://d-maps.com/carte.php?num_car=6021&lang=en" target="_blank">https://d-maps.com/carte.php?num_car=6021&lang=en</a>, accessed on 10 January 2022). Full article ">Figure 2
Sample image and the mitochondrial genome map of Chirolophis wui. (a) Specimen reference image; (b) the mitochondrial genome of C. wui. Genes outside the circle are transcribed in a clockwise direction and those inside in a counterclockwise direction. Full article ">Figure 3
Graphical representation of nucleotide composition contents and AT and GC skew. They should be listed as: (a) nucleotide composition AT% and GC%; (b) AT and GC skew. Full article ">Figure 4
Inferred secondary structures of 23 tRNAs from C. wui. Full article ">Figure 5
The phylogenetic tree was obtained using the complete mitochondrial genome sequences from ten species (nine from the Stichaeidae family and Cottus szanaga from the Cottidae family as an outgroup) and 1000 bootstrap repetitions using the maximum-likelihood approach. The numbers on the branches represent the bootstrap values, and the star next to Chirolophis wui denotes the species used in this research. Full article ">

15 pages, 1763 KiB

Open AccessArticle

Pitx1 Enhancer Variants in Spined and Spine-Reduced Subarctic European Sticklebacks

by Dhurba Adhikari, Ida K. Hanssen, Steinar D. Johansen, Truls B. Moum and Jarle T. Nordeide

Fishes 2023, 8(3), 164; https://doi.org/10.3390/fishes8030164 - 15 Mar 2023

Cited by 1 | Viewed by 2845

Abstract

Loss of body armour, sometimes including a reduction in or loss of pelvic spines, is an adaptation observed in many isolated freshwater populations. Pelvic reduction in sticklebacks has previously been associated with recurrent, but variant, deletions within pelvic enhancer regions PelA and [...] Read more.

Loss of body armour, sometimes including a reduction in or loss of pelvic spines, is an adaptation observed in many isolated freshwater populations. Pelvic reduction in sticklebacks has previously been associated with recurrent, but variant, deletions within pelvic enhancer regions PelA and PelB, which regulate expression of the homeodomain transcription factor gene Pitx1. We investigated variation in nucleotide sequences of pelvic enhancers in sticklebacks collected from two small freshwater lakes in the same watercourse and a nearby marine site in subarctic Norway. Spineless, as well as asymmetrically spined and completely spined sticklebacks are present in the upper lake, while only specimens with complete spines are found at the other lake and the marine site. Observed variation at PelA between the three sites was mainly due to variable numbers of repeats at three fragile TG-repeat loci. The length of PelA, mainly at one of the TG-repeat loci, was consistently shorter among individuals in the upper lake compared with specimens from the two other sites. However, no obvious association was revealed between enhancer variants and pelvic status. No polymorphism was found at PelB. Thus, additional genetic factors and/or environmental cues need to be identified to fully explain the occurrence of pelvic reduction in sticklebacks in this lake. Full article

(This article belongs to the Section Genetics and Biotechnology)

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(a) Pitx1 with the upstream and downstream enhancers PelA and PelB, respectively. (b) PelA with TG-repeats I, II, and III, and their relative location. FP1-3 and RP1-3 show the location of the forward and reverse primers used to sequence TG-repeat I, II, and III, respectively. (c) The reference sequence (SALR GU130435; 377,852 nt) is from a stickleback collected in Salmon River, British Columbia, and harbours 28, 15, and 54 TG-repeats at TG-repeat I, II, and III, respectively. Full article ">Figure 2
(a) Scandinavia with the study site encircled in red. (b) Map (<a href="http://www.norgeskart.no" target="_blank">www.norgeskart.no</a> accessed on 28 March 2023) of the upper Lake Storvatnet (68°46′49″ N, 15°9′36″ E) and the lower Lake Gjerdhaugvatnet in the watercourse, whereas the marine sampling site (not shown) is located about 8 km from the two lakes. (c) Schematic drawing (out of scale) of the three sites showing the symmetric-spined, asymmetric-spined, and the spineless (encircled in red) sticklebacks in Lake Storvatnet. All specimens are symmetric spined at the two other sites. Full article ">Figure 3
Representative examples of allelic variants of PelA caused by variable numbers of TG dinucleotides at TG-repeats I–III. The repeat number of the most common allelic variants is shown for each of the five groups of sticklebacks examined. For more details see the <a href="#app1-fishes-08-00164" class="html-app">Supplementary Figures S2 and S3</a>. Full article ">Figure 4
Box–whisker plots showing the number of repeats of (a) TG-I, (b) TG-II, and (c) TG-III, for spineless, symmetric, and asymmetric specimens from Lake Storvatnet, and spined specimens from Lake Gjerdhaugvatnet and the marine site. See also <a href="#app1-fishes-08-00164" class="html-app">Supplementary Figures S2 and S3</a>. Numbers (“N”) in the figure show the number of alleles examined. Full article ">Figure 5
(a) The relative positions of the Pitx1 gene and its upstream and downstream enhancers, PelA and PelB. In addition, the relative positions within PelA of TG-repeat I (green), TG-repeat II (grey), and TG-repeat III (blue) are also shown. The approximate downstream position (out of scale) of PelB (grey) is indicated as well, as are the number of TG-repeats at TG-repeat I, II, and III for the reference sequence (GU130435) from Salmon River, British Columbia. (b) Polymorphism at TG-repeat I, II, and III located at PelA, and at PelB in spineless sticklebacks from three previously published studies from Paxton Benthic Lake (PAXB), Bear Paw Lake (BEPA), and Hump Lake (HUMP) from the west coast of North America [<a href="#B28-fishes-08-00164" class="html-bibr">28</a>]. Spineless, asymmetric-spined, and symmetric-spined sticklebacks from the present study sites of Lake Storvatnet (Storvatn), Lake Gjerdhaugvatnet (Gjerdhaugvatn), and the marine sample (Marine) in sub-Arctic Norway at the north-east coast of Europe are also shown. Missing regions at PelA compared with the reference sequence are indicated in red. Full article ">

16 pages, 1024 KiB

Open AccessArticle

Influence of Total Suspended Solids on the Growth of the Sea Lettuce Ulva lactuca Integrated with the Pacific White Shrimp Litopenaeus vannamei in a Biofloc System

by Andrezza Carvalho, Léa Carolina de Oliveira Costa, Mariana Holanda, Luís H. Poersch and Gamze Turan

Fishes 2023, 8(3), 163; https://doi.org/10.3390/fishes8030163 - 15 Mar 2023

Cited by 11 | Viewed by 3100

Abstract

A biofloc system is rich in nutrients, which favors the cultivation of macroalgae, but the influence of the system on the performance of macroalgae is unknown. The objective of this study was to analyze the feasibility of introducing the macroalgae Ulva lactuca into [...] Read more.

A biofloc system is rich in nutrients, which favors the cultivation of macroalgae, but the influence of the system on the performance of macroalgae is unknown. The objective of this study was to analyze the feasibility of introducing the macroalgae Ulva lactuca into the culture of Litopenaeus vannamei in a biofloc system. The first experiment evaluated the influence of 400 mg L⁻¹ and 30 mg L⁻¹ solids concentration of the system in biofloc and von Stosch culture medium on macroalgae growth. In the second experiment, the densities of 1, 2, and 3 g L⁻¹ of U. lactuca were cultivated in an integrated system with shrimp and monoculture treatment. Both experiments had 35 days of cultivation. There was no significant difference in macroalgae growth between the treatments with biofloc and von Stosch culture medium. In the integrated culture, the density of 1 g L⁻¹ showed better nutrient absorption. Shrimp performance was not affected by macroalgae cultivation. In conclusion, the solids did not affect the growth of the macroalgae, and it could be cultivated in a biofloc system for nitrate uptake in integrated culture with shrimp. Full article

(This article belongs to the Special Issue Integrated Aquaculture and Monoculture of Low-Trophic Species)

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Figure 1
The rectangular floating structure used for <italic>U. lactuca</italic> cultivation in the shrimp tank. Full article ">Figure 2
Weekly turbidity values in the DEC (with 30 mg L−1 of TSS), BFT (with 400 mg L−1 of TSS), and vs. (with von Stosch enrichment solution at a concentration of 10 mL L−1) treatment groups during the 35 days of the experimental period. a, b, c = Different letters on the same day represent a significant difference (<italic>p</italic> ≤ 0.05) between the treatments after one-way ANOVA with Tukey’s post-hoc test. Full article ">Figure 3
Variations in the nitrate concentrations in the IMTA 1 (with 1 g Ulva L−1), IMTA 2 (2 g Ulva L−1), IMTA 3 (3 g Ulva L−1), and MONO C (with no Ulva) treatment groups during the 35 days of cultivation. a, b = Different lowercase letters represent a significant difference (<italic>p</italic> ≤ 0.05) on the same days between the treatments after performing one-way ANOVA followed by Tukey’s post-hoc test. Full article ">Figure 4
Variations in the total suspended solids (TSS) in the IMTA 1 (with 1 g Ulva L−1), IMTA 2 (2 g Ulva L−1), IMTA 3 (3 g Ulva L−1), and MONO C (with no Ulva) treatment groups during the 35 days of cultivation. a, b = Different lowercase letters on the same day represent a significant difference (<italic>p</italic> ≤ 0.05) between the treatments after ANOVA followed by Tukey’s post-hoc test. Full article ">

9 pages, 727 KiB

Open AccessArticle

Population Genetics of Chilean Jack Mackerel, Trachurus murphyi Nichols, 1920, (Pisces, Carangidae), in Waters of the South Pacific Ocean

by Sandra Ferrada Fuentes, Ricardo Galleguillos, Victoria Herrera-Yáñez and Cristian B. Canales-Aguirre

Fishes 2023, 8(3), 162; https://doi.org/10.3390/fishes8030162 - 13 Mar 2023

Cited by 2 | Viewed by 2487

Abstract

Estimating genetic diversity and population structure with polymorphic markers might provide information for the better management of fish that have economic importance. We used the Chilean jack mackerel, Trachurus murphyi, a pelagic species distributed in the south Pacific Ocean, to test the [...] Read more.

Estimating genetic diversity and population structure with polymorphic markers might provide information for the better management of fish that have economic importance. We used the Chilean jack mackerel, Trachurus murphyi, a pelagic species distributed in the south Pacific Ocean, to test the population genetic structure across its distribution. A total of 522 samples were collected from 11 locations in 2008, to be analyzed using six loci microsatellites. We conducted traditional genetic analyses to describe the genetic diversity of T. murphyi and whether it shows spatial genetic structure. The results showed a high genetic diversity across locations (Ho = 0.551 to 0.980; He = 0.676 to 0.959). Estimates for the population structure showed a low and non-significant pairwise F_ST in all comparisons. We supported the non-genetic differentiation previously reported with the used microsatellite panel. Further comparative temporal studies should be conducted to identify the stability of this pattern. Overall, this study reinforces the hypothesis that, in the Pacific Ocean, Chilean jack mackerel correspond to a large single population. Full article

(This article belongs to the Section Genetics and Biotechnology)

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10 pages, 2318 KiB

Open AccessArticle

Characteristics of Sound Attenuation by Individual and Multiple Fishes

by Hansoo Kim, Sungho Cho, Jee Woong Choi and Donhyug Kang

Fishes 2023, 8(3), 161; https://doi.org/10.3390/fishes8030161 - 13 Mar 2023

Viewed by 1812

Abstract

Fish biomass and stock assessment are estimated from acoustic volume backscattering strengths (Sv) obtained from various hydroacoustic equipment. Although sound attenuation due to fish schools and water influences the Sv value, only attenuation from water is considered during the acoustic data process. For [...] Read more.

Fish biomass and stock assessment are estimated from acoustic volume backscattering strengths (Sv) obtained from various hydroacoustic equipment. Although sound attenuation due to fish schools and water influences the Sv value, only attenuation from water is considered during the acoustic data process. For these reasons, it is necessary to understand the characteristics of sound attenuation by fish. Unfortunately, little is known about sound attenuation from fish. In the present study, the attenuation from one to four fish specimens was precisely measured during ex situ experiments in a water tank. The scientific echo sounder of a split-beam 200 kHz transducer and a miniature hydrophone were used for the attenuation measurements. Results show that the maximum attenuation coefficient (α) was approximately 25 dB/cm when the 4 multiple fishes had high fish heights. The relationship between the attenuation coefficient (

α_{200 k H z}

) and the total fish height (

H_{t o t a l}

) was approximately

α_{200 k H z} = 0.54 * H_{t o t a l} \pm 0.06

(

r^{2} = 0.72

). This work describes the sound attenuation characteristics to provide basic information for the compensation of Sv from fish schools or layers. Full article

(This article belongs to the Special Issue Application of Acoustics in Fisheries)

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16 pages, 2293 KiB

Open AccessArticle

Age and Growth of the Threatened Smalleye Round Ray, Urotrygon microphthalmum, Delsman, 1941, from Northeastern Brazil

by Jones Santander-Neto, Francisco Marcante Santana, Jonas Eloi Vasconcelos-Filho and Rosângela Lessa

Fishes 2023, 8(3), 160; https://doi.org/10.3390/fishes8030160 - 12 Mar 2023

Viewed by 2227

Abstract

The age and growth of Urotrygon microphthalmum were studied using specimens captured between March 2010 and March 2012 as by-catch in the shrimp trawl fishery off the coast of the state of Pernambuco, Brazil. A total of 347 vertebrae were read, 161 from [...] Read more.

The age and growth of Urotrygon microphthalmum were studied using specimens captured between March 2010 and March 2012 as by-catch in the shrimp trawl fishery off the coast of the state of Pernambuco, Brazil. A total of 347 vertebrae were read, 161 from males (81.6–249.55 mm) and 186 from females (86.15–298.1 mm). The estimated average percentage index (IAPE) ranged from 0.71% to 4.33% (mean = 2.5%) in vertebrae from specimens with 1 and 6 band pairs, respectively. In the present study, the different approaches to validation produced variable results (partially valid growth zones). We then decided to discuss the growth of the species considering the formation of an annual ring. There were statistically significant differences in growth between the sexes. The best model to describe male growth was the von Bertalanffy growth model for two phases (VBGM TP) with growth parameters L_∞ (maximum theoretical length) = 230.35 mm, k (growth constant) = 1.00, t₀ (theoretical age of size zero) = −0.76 years and for females it was the von Bertalanffy with birth size (VBGM L₀) model with parameters L_∞ = 282.55 mm, k = 0.37. The age of maturity for males and females was 1.52 and 2.02 years, respectively, and the maximum age observed was 5.5 and 8.5 years, respectively. Despite being a fast-growing species, Urotrygon microphthalmum is threatened, probably due to the high mortality levels from shrimp trawling in a very narrow range of the shelf where all the life stages are captured. Full article

(This article belongs to the Special Issue Elasmobranch Biodiversity, Conservation and Management)

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Figure 1

Figure 1
Frequency distribution of total length of Urotrygon microphthalmum captured in northeastern Brazil. Black bars, males; gray bars, females. Full article ">Figure 2
Error in the number of band pairs counted from Urotrygon microphthalmum captured in northeastern Brazil. The gray diagonal line indicates a one-to-one relationship. Full article ">Figure 3
The opaque and translucent proportion of vertebral band (dashed line) and marginal increment ratio (continuous line with standard deviation) of Urotrygon microphthalmum from northeastern Brazil. Full article ">Figure 4
Growth curves estimated for Urotrygon microphthalmum from northeastern Brazil. (A) male, one ring per year; (B) female, one ring per year; (C) male, two rings per year; (D) female, two rings per year. Gray circles are observed age. Full article ">Figure 5
Age distribution for Urotrygon microphthalmum from northeastern Brazil, considering (A) one ring per year and, (B) two rings per year. Black bars, males; gray bars, females. Full article ">

18 pages, 2792 KiB

Open AccessFeature PaperArticle

Application of a Lipopolysaccharide (LPS)-Stimulated Mitogenesis Assay in Smallmouth Bass (Micropterus dolomieu) to Augment Wild Fish Health Studies

by Cheyenne R. Smith, Christopher A. Ottinger, Heather L. Walsh, Patricia M. Mazik and Vicki S. Blazer

Fishes 2023, 8(3), 159; https://doi.org/10.3390/fishes8030159 - 10 Mar 2023

Viewed by 2053

Abstract

The utility of a functional immune assay for smallmouth bass (Micropterus dolomieu) lymphocyte mitogenesis was evaluated. Wild populations in the Potomac River have faced disease and mortality with immunosuppression from exposure to chemical contaminants a suspected component. However, a validated set [...] Read more.

The utility of a functional immune assay for smallmouth bass (Micropterus dolomieu) lymphocyte mitogenesis was evaluated. Wild populations in the Potomac River have faced disease and mortality with immunosuppression from exposure to chemical contaminants a suspected component. However, a validated set of immune parameters to screen for immunosuppression in wild fish populations is not available. Prior to use in ecotoxicology studies, ancillary factors influencing the mitogenic response need to be understood. The assay was field-tested with fish collected from three sites in West Virginia as part of health assessments occurring in spring (pre-spawn; April–May) and fall (recrudescence; October–November). Anterior kidney leukocytes were exposed to lipopolysaccharide (LPS) from E.coli O111:B4 or mitogen-free media and proliferation was measured using imaging flow cytometry with advanced machine learning to distinguish lymphocytes. An anti-smallmouth bass IgM monoclonal antibody was used to identify IgM+ lymphocytes. Lymphocyte mitogenesis, or proliferative responses, varied by site and season and positively and negatively correlated with factors such as sex, age, tissue parasites, and macrophage aggregates. Background proliferation of IgM− lymphocytes was negatively correlated to LPS-induced proliferation in both seasons at all sites, but only in spring for IgM+ lymphocytes. The results demonstrate that many factors, in addition to chemical contaminants, may influence lymphocyte proliferation. Full article

(This article belongs to the Special Issue Study in Immune System and Disease of Fishes)

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16 pages, 5030 KiB

Open AccessArticle

Impacts of Land Cover Changes on Catches of Nile Perch and Nile Tilapia on Lake Kyoga, Uganda

by Rebecca Walugembe Nambi, Abebe Getahun, Fredrick Jones Muyodi and Edward Rukuunya

Fishes 2023, 8(3), 158; https://doi.org/10.3390/fishes8030158 - 10 Mar 2023

Cited by 1 | Viewed by 2789

Abstract

In East Africa, Nile perch and Nile tilapia are major commercial fish species, providing reliable protein and income sources. However, their stocks are dwindling on Lake Kyoga due to land use and land cover (LULC) changes within the surrounding catchment. Thus, this paper [...] Read more.

In East Africa, Nile perch and Nile tilapia are major commercial fish species, providing reliable protein and income sources. However, their stocks are dwindling on Lake Kyoga due to land use and land cover (LULC) changes within the surrounding catchment. Thus, this paper aims at assessing the land use land cover on Lake Kyoga and its immediate catchment and how those changes affect the water quality and the local fish catches. The Iso-Cluster tool in ArcGIS was used to analyze Landsat images from the years 1989 to 2021 to obtain LULC information. The LULC classes were classified into water, wetland, agricultural land, rangeland, and settlements. Correction using a 2-tailed test of the water quality parameters with the LULC classes indicated a strong positive correlation of TN with water (0.71), a strong negative correlation of TP with rangelands (−0.83), and a strong positive correlation of Chl-a with settlement (0.98) at a 0.05 confidence level. The correlation of the recorded fish catch data with fishing gear showed a strong negative correlation with cast and monofilament nets. Continued use of illegal fishing gear was ranked number 1 of the causes of LULC by the stakeholders. Thus, the fisheries managers should collaborate with local stakeholders to boost declining fish catches for improved livelihoods and sustainable management. Full article

(This article belongs to the Special Issue New Trends in Freshwater Fishes)

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20 pages, 5790 KiB

Open AccessArticle

Integrative Analysis to Manage Aquatic Resources Based on Fish Feeding Patterns in Neotropical Rivers

by Estevan Luiz da Silveira, Nabil Semmar, Eduardo Luis Cupertino Ballester and André Martins Vaz-dos-Santos

Fishes 2023, 8(3), 157; https://doi.org/10.3390/fishes8030157 - 6 Mar 2023

Cited by 3 | Viewed by 2473

Abstract

Feeding ecology is an integrative procedure to highlight different diets, associating feeding trends with governing and regulation factors characterizing foraging species and their environments, respectively. The diet variability of seven fish species forming a community in a Neotropical riverine system was analyzed to [...] Read more.

Feeding ecology is an integrative procedure to highlight different diets, associating feeding trends with governing and regulation factors characterizing foraging species and their environments, respectively. The diet variability of seven fish species forming a community in a Neotropical riverine system was analyzed to characterize the resource and consumer linkages, providing a detailed assessment of adaptive feeding behaviors of fishes living in different ecological states transiting from natural/resilient spaces to anthropic pressions-linked disturbed ones. Fishes were sampled along four sites during a year, and their stomach contents were analyzed. Feeding data were analyzed by applying quali- and quantitative methods with multi-levels and multifactor aspects to determine target food categories (percentage of occurrence) and identify feeding patterns (correspondence and cluster analyses, CA-HCA). Factors and scales governing target food categories were also tested. A total of 483 stomachs were dissected, and 30 food categories were identified. CA-HCA highlighted 10 feeding trends (FTs) combining several foods co-occurring at distinct levels. These FTs indicated characteristic diets and high diversity of feeding behaviors concerning multiple and narrow diets, different alimentary needs related to ecomorphological features, different plasticity ranges (adaptability, tolerance) and a spatial governing effect (headwater to river mouth environmental quality loss). These multiple factors provided essential information on overcoming ways of environmental constraints and optimization ways of food balances helping to better manage the richness and working of neotropical river systems. Full article

(This article belongs to the Special Issue Trophic Ecology of Fishes)

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Figure 1
Verde River basin and sampling sites. (A) South America and the Upper Paraná River Ecoregion (UPRE, in black); (B) UPRE and the Tibagi River basin (TRB, in black); (C) TRB and the Pitangui River basin (PRB, in black); (D) PRB and the Verde River basin (in black); (E) Hydrography; (F) Devonian Escarpment Environmental Protection Area; (G) Campos Gerais National Park; (H) Water flow direction. Adapted and modified from [<a href="#B38-fishes-08-00157" class="html-bibr">38</a>]. Full article ">Figure 2
Spatial distribution of fish species sampled with stomachs contents of the fish community from Verde River. Full article ">Figure 3
Dendrogram highlighting ten feeding trends characterized by high relative consumptions of different food types of the fish community from Verde River. Full article ">Figure 4
Factorial plots given by the 10 principal components of correspondence analysis applied on food data of the fish community from Verde River. (a,c,e,g,i) Food variables’ plots. (b,d,f,h,j) Feeding trends of individual fishes. Different colors were used to distinguish between different food categories (left plots) and between feeding trends (right plots). (Acarina: Acarina; Bacil: Bacillariophyta; Blatto: Blattodea; Bryo: Bryophyta; Coleo: Coleoptera; Cyano: Cyanophyta; Det/Sed: Detritus/Sediments; Dipter: Diptera; Ephem: Ephemeroptera; Gast: Gastropoda; Hemi: Hemiptera; InsFrag: Insect fragments; InvEgg: Invertebrates eggs; Isopoda: Isopoda; Lepid: Lepidoptera; Neuro: Neuroptera; Odon: Odonata; Oligo: Oligochaeta; Orthop: Orthoptera; PlantFrag: Plant Fragments; Plastic: Plastic; Teleo: Teleostei; Tricho: Trichoptera; UndIns: Undetermined Insects). Full article ">Figure 5
Feeding trends identified in the diet of the fish community from Verde River (A) by species and (B) by site. FTs = Feeding trends; P.fas = Psalidodon aff. fasciatus; P.par = Psalidodon paranae; Apa.sp = Apareiodon sp.; C.ehr = Corydoras ehrhardti; H.str = Hypostomus strigaticeps; R.que = Rhamdia quelen; G.bra = Geophagus brasiliensis. Full article ">Figure 6
Spatial distribution of the feeding trends (FT) identified in the diet of the fish community from Verde River. P.fas = Psalidodon aff. fasciatus; P.par = P. paranae; Apa.sp = Apareiodon sp.; C.ehr = Corydoras ehrhardti; H.str = Hypostomus strigaticeps; R.que = Rhamdia quelen; G.bra = Geophagus brasiliensis. Full article ">Figure 7
Schematic network showing the different feeding characteristics and interactions of the fish community from Verde River. H: headwater (red lines); U: upper middle stretch (blue lines); L: lower middle stretch (green lines); M: river mouth (purple lines); FTs = Feeding trends; P.fas = Psalidodon aff. fasciatus; P.par = Psalidodon paranae; Apa.sp = Apareiodon sp.; C.ehr = Corydoras ehrhardti; H.str = Hypostomus strigaticeps; R.que = Rhamdia quelen; G.bra = Geophagus brasiliensis. Full article ">

13 pages, 1705 KiB

Open AccessArticle

Zebrafish Sexual Behavior in Plain and Enriched Environments: Parameters in the Valproate Model of Autism

by Xiomara Velázquez-Landa, Porfirio Carrillo, Genaro A. Coria-Avila, Deissy Herrera-Covarrubias, Luis I. García, María Rebeca Toledo-Cárdenas, María Elena Hernández-Aguilar and Jorge Manzo

Fishes 2023, 8(3), 156; https://doi.org/10.3390/fishes8030156 - 5 Mar 2023

Cited by 5 | Viewed by 2507

Abstract

Autism is a complex alteration in children’s developing nervous system that manifests in behavioral patterns that do not match those of typical subjects. Moreover, starting at puberty, these children may encounter problems regarding social interaction related to sexual encounters. As studies are scarce, [...] Read more.

Autism is a complex alteration in children’s developing nervous system that manifests in behavioral patterns that do not match those of typical subjects. Moreover, starting at puberty, these children may encounter problems regarding social interaction related to sexual encounters. As studies are scarce, we used the valproate model of autism in the zebrafish to contribute to the knowledge related to sexual behavior in this disorder. Young zebrafish were reproduced, embryos collected, and organized in groups of control or treated with valproic acid, as the autism model. Sexual behavior was recorded in fish from these embryos as they became sexually active. The results show that the zebrafish’s sexual behavior is organized into appetitive, preconsummatory, and consummatory behaviors, as in other vertebrates. In the autism model, the patterns of sexual behavior are present but with significant modifications. The behavior of males was the most affected, while in females, the most affected parameter was oviposition. These results show that, in the autism model of zebrafish, sexual behavior is not suppressed, but it seems that critical changes occur in the neuroendocrine system that reduces reproductive success. Furthermore, the enriched environment was beneficial in maintaining the consummatory behaviors of females and males with autism-like behaviors. Full article

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Full article ">Figure 1
Environment conditions. The image shows the lab-designed hatch tanks. The two tanks on the left are those with EE environments, and the two on the right are those with the PL environments. Tank dividers were opaque. Larger tanks had a similar arrangement. Full article ">Figure 2
Zebrafish sexual behavior. Time course (left to right) of appetitive, preconsummatory, and consummatory behaviors. See <a href="#fishes-08-00156-t001" class="html-table">Table 1</a> for behavioral descriptions. Full article ">Figure 3
Latency to initiate appetitive, preconsummatory, and consummatory behaviors. Neither treatment nor environment produced significant changes between groups. The female consummatory behaviors were the last executed in all four groups during interplay. Data show the mean ± SEM. Full article ">Figure 4
Appetitive behavior. The graph shows how often the female (a) and male (b) approached each other (frequency), and how long they stayed near each other before withdrawing (duration). Data show the mean ± SEM. * = p < 0.05. Full article ">Figure 5
Female preconsummatory behaviors. The graph shows how many times the female escort (a) and halt (b) the male (frequency), and how long such behaviors were displayed for (duration). Data show the mean ± SEM. * = p < 0.05. Full article ">Figure 6
Male preconsummatory behaviors. The graph shows how many times the male touched (a) and encircled (b) the female (frequency) and how long he displayed such behaviors for (duration). Data show the mean ± SEM. * = p < 0.05; ** = p < 0.01. Full article ">Figure 7
Female consummatory behaviors. The graph shows how many times the female guided the male (a) and displayed oviposition (b) (frequency), and how long she displayed such behaviors for (duration). Data show the mean ± SEM. * = p < 0.05; ** = p < 0.01. Full article ">Figure 8
Zigzag and quiver behaviors in males. The graph shows how many times the male executed the zigzag (a) and quiver (b) behaviors (frequency), and how long he displayed such behaviors for (duration). Data show the mean ± SEM. * = p < 0.05; ** = p < 0.01. Full article ">

11 pages, 1527 KiB

Open AccessArticle

Modelling Early Growth of Totoaba macdonaldi (Teleostei: Sciaenidae) under Laboratory Conditions

by Marcelo V. Curiel-Bernal, Miguel Á. Cisneros-Mata, Guillermo Rodríguez-Domínguez, Laura Sánchez-Velasco, S. Patricia A. Jiménez-Rosenberg, Alejandro Parés-Sierra and E. Alberto Aragón-Noriega

Fishes 2023, 8(3), 155; https://doi.org/10.3390/fishes8030155 - 4 Mar 2023

Cited by 3 | Viewed by 2713

Abstract

The totoaba (Totoaba macdonaldi) is a sciaenid (croaker) fish endemic to the Gulf of California with high commercial importance. Because it was considered at risk of extinction (since 2021 it was reclassified as vulnerable by the IUCN), and aquaculture procedures were [...] Read more.

The totoaba (Totoaba macdonaldi) is a sciaenid (croaker) fish endemic to the Gulf of California with high commercial importance. Because it was considered at risk of extinction (since 2021 it was reclassified as vulnerable by the IUCN), and aquaculture procedures were developed for restocking and commercial purposes. The present study was conducted with the hypothesis that the early stages of totoaba present depensatory individual growth and an observed variance-at-age modelling approach is the best way to parametrize growth. Ten models were tested including asymptotic, non-asymptotic, exponential-like, and power-like curves including a new one that represents a modification of Schnute’s model. The model that best described the growth trajectory of larval and early juveniles of T. macdonaldi in a controlled environment is a sigmoid curve with two inflexions, related to changes in the feeding regime. Full article

(This article belongs to the Section Biology and Ecology)

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12 pages, 501 KiB

Open AccessEditor’s ChoiceCommunication

Determination of Multi-Class Antibiotics Residues in Farmed Fish and Shrimp from Sri Lanka by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS)

by G. D. T. M. Jayasinghe, Joanna Szpunar, Ryszard Lobinski and E. M. R. K. B. Edirisinghe

Fishes 2023, 8(3), 154; https://doi.org/10.3390/fishes8030154 - 4 Mar 2023

Cited by 8 | Viewed by 3573

Abstract

Antibiotics have been used to control the aquatic environment in both therapeutic and prophylactic ways. Antibiotics are particularly difficult to extract due to their strong interactions with biological matrices. In this study, UPLC-MS/MS method was developed and validated for quantitative confirmatory analysis of [...] Read more.

Antibiotics have been used to control the aquatic environment in both therapeutic and prophylactic ways. Antibiotics are particularly difficult to extract due to their strong interactions with biological matrices. In this study, UPLC-MS/MS method was developed and validated for quantitative confirmatory analysis of multi-class antibiotics residues in fish and shrimp. Fourteen antibiotics belonging to sulphonamides, β-lactams, quinolones, sulfones and macrolides were determined within one chromatographic run. The samples were suspended in 0.1 M HCl, and the analytes were extracted into ethyl acetate. The extracts were defatted with cyclohexane. The limits of quantification (LOQ) ranged from 0.24 to 1.32 µg kg⁻¹ for fish and 0.42–1.62 µg kg⁻¹ for shrimp samples. The recoveries ranged from 75 to 105%. The method was applied to the analysis of farmed freshwater Tilapia fish (Oreochromis niloticus) and shrimp (Penaeus monodon) collected in Sri Lanka. Sulfacetamide (4.31 ± 0.70 µg kg⁻¹) and sulfamethoxypyridazine (0.75 ± 0.15 µg kg⁻¹) were detected in the fish, and sulfapyridine (0.21–0.56 µg kg⁻¹) and sulfadoxine (0.35–1.44 µg kg⁻¹) were detected in the shrimp samples. The concentrations complied with the EU regulation limits for veterinary drug residues in seafood and did not pose a risk in terms of food safety. Full article

(This article belongs to the Section Sustainable Aquaculture)

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15 pages, 350 KiB

Open AccessArticle

The Protective Effects of Korill Product on Carp Fingerlings Reared in High Densities and Challenged with Albendazole Treatment

by Lacrămioara (Grădinariu) Năstac, Lorena Dediu, Mirela Crețu, Cristian Rîmniceanu, Angelica Docan, Iulia Grecu, Floricel Maricel Dima, Maria Desimira Stroe and Camelia Vizireanu

Fishes 2023, 8(3), 153; https://doi.org/10.3390/fishes8030153 - 4 Mar 2023

Cited by 2 | Viewed by 2090

Abstract

The objectives of the present study were to evaluate the potential of the Korill (KO), a product based on krill oil, supplemented in fish feed (5 g/kg feed) to alleviate density-induced stress in carp fingerlings, and its protective capacity in case of anthelmintic [...] Read more.

The objectives of the present study were to evaluate the potential of the Korill (KO), a product based on krill oil, supplemented in fish feed (5 g/kg feed) to alleviate density-induced stress in carp fingerlings, and its protective capacity in case of anthelmintic drug administration (ABZ—albendazole). Thus, the fish were divided into four groups: LD (low density with normal feed), LD-KO (low density with KO supplementation feed), HD (high density with normal feed), and HD-KO (high density with KO supplementation feed). During the first trial, the fish held under different densities were fed normal feed and KO feed for two months, following a 2 × 2 factorial experimental design. In the second trial, seven fish per tank were subjected, for one week, to albendazole treatment (administered daily by an oral dose of 5 mg/kg body weight). For both trials, blood and plasma samples were used to quantify hematological and biochemical parameters. The results showed that the KO diet alleviated the negative impact of ABZ treatment on liver function and the metabolic profile of carp fingerlings reared in high densities. In addition, KO feeding improved lysozyme activity (LZM) and therefore the immune status of the fish, and reduced oxidative damage in the liver, demonstrated by a decrease of malondialdehyde (MDA) content and an increase of total antioxidant capacity (TAC). Full article

(This article belongs to the Section Welfare, Health and Disease)

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9 pages, 3940 KiB

Open AccessCommunication

Successful Ultrasonography-Assisted Artificial Reproduction of Critically Endangered Sichuan taimen (Hucho bleekeri)

by Xiaoqian Leng, Hao Du, Wei Xiong, Peilin Cheng, Jiang Luo and Jinming Wu

Fishes 2023, 8(3), 152; https://doi.org/10.3390/fishes8030152 - 3 Mar 2023

Cited by 5 | Viewed by 2215

Abstract

Sichuan taimen (Hucho bleekeri), a critically endangered species, is listed as a first-class protected species in China. The natural population has been missing from most of its known distribution areas for many years but was rediscovered in the Taibai River in [...] Read more.

Sichuan taimen (Hucho bleekeri), a critically endangered species, is listed as a first-class protected species in China. The natural population has been missing from most of its known distribution areas for many years but was rediscovered in the Taibai River in 2012, providing an important resource for the conservation stocking of the Sichuan taimen. In this study, 43 wild adult Sichuan taimen collected from the Taibai River were determined for gamete maturity for artificial reproduction using ultrasonography. The echogenicity of the gonads before and after hormonal induction was described to determine broodstock identification, injection dose of hormones, and spawning time. Four batches of artificial breeding were successfully achieved in 2013, 2014, and 2016. Broodstock (19 females and 16 males) spawned with average fertilization and hatching rates reaching 80.2% and 61.0%, respectively. This study demonstrates that ultrasonic imaging is a convenient and efficient method to track the state of gonads of mature Sichuan taimen during artificial reproduction, which will assist in broodstock cultivation, and further large-scale proliferation and effective resource restoration of the Sichuan taimen. Full article

(This article belongs to the Special Issue Advances in Endangered Aquatic Animals Protection)

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27 pages, 2082 KiB

Open AccessArticle

Has the Regulatory Compliance Burden Reduced Competitiveness of the U.S. Tilapia Industry?

by Carole R. Engle, Jonathan van Senten, Charles Clark and Noah Boldt

Fishes 2023, 8(3), 151; https://doi.org/10.3390/fishes8030151 - 2 Mar 2023

Cited by 10 | Viewed by 3703

Abstract

Emerging research on aquaculture governance has pointed to the conundrum of negative global environmental effects from economic incentives for aquaculture production to shift from more highly regulated to less regulated countries. This study has focused on examining whether regulatory costs on U.S. tilapia [...] Read more.

Emerging research on aquaculture governance has pointed to the conundrum of negative global environmental effects from economic incentives for aquaculture production to shift from more highly regulated to less regulated countries. This study has focused on examining whether regulatory costs on U.S. tilapia farms may have contributed to their contraction in contrast to the growth of global tilapia production that contributes to the volume of seafood imports into the U.S. A national survey (coverage rate = 75% of tilapia sold; response rate = 18%) found that on-farm regulatory costs accounted for 15% of total production costs on U.S. tilapia farms, the fifth-highest cost of production. The total direct regulatory costs nationally were $4.4 million, averaging $137,611/farm. Most problematic were regulations of effluent discharge, predatory bird control, international export, and water and energy policies. Manpower costs for monitoring and reporting were the greatest cost of regulatory compliance. The lost sales revenue resulting from regulations was $32 million a year, or 82% of total annual sales, indicating that the regulatory framework has constrained the growth of U.S. tilapia farming. The smallest tilapia farms had the greatest regulatory cost per kg. This study provides evidence that regulatory costs, along with other challenges related to live fish markets, have contributed to the decline in U.S. tilapia production. Increased competitiveness of the U.S. tilapia industry will require a combination of: (1) improved regulatory efficiency that reduces on-farm cost burdens without reducing societal benefits; (2) research and on-farm extension assistance to evaluate new tilapia fillet equipment; and (3) research on changing consumer preferences to provide guidance on effective strategies to penetrate the large U.S. fillet market. Full article

(This article belongs to the Section Sustainable Aquaculture)

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U.S. states reporting at least one tilapia farm in 2018. SOURCE: 2018 Census of Aquaculture (USDA-NASS 2019). Full article ">Figure 2
U.S. tilapia sales and number of farms, 1997 to 2018. SOURCE: USDA-NASS. Full article ">Figure 3
Producer responses to the following question: “We would like to put the importance of regulatory effects in the context of your overall business. What would you say are the top 5 biggest problems for your business? Please rank your top 5 problems with #1 being the biggest problem.” (n = 24 respondents). Full article ">Figure 4
Producer responses to the following question: “Of all the regulations you deal with, which have created the greatest problems for your business, with #1 being the most problematic.” (n = 24 respondents). “Other” includes: low-cost imports as barrier to entry, disease control (lack of approved antibiotics), FDA/processing regulations, OSHA, banking regulations, the cumulative effect of the total suite of regulations. Full article ">Figure 5
Regulatory costs by type of cost (% of regulatory costs). Full article ">Figure 6
Regulatory cost by type of regulation (% of regulatory cost). Full article ">

8 pages, 896 KiB

Open AccessCommunication

The Complete Mitochondrial Genome of the Fivespot Flounder, Pseudorhombus pentophthalmus (Pleuronectiformes: Paralichthyidae), from Korea and Its Phylogenetic Analysis

by Yong-Suk Lee, Maheshkumar Prakash Patil, Jong-Oh Kim, Yu-Jin Lee, Yong Bae Seo, Jin-Koo Kim, Rahul K. Suryawanshi and Gun-Do Kim

Fishes 2023, 8(3), 150; https://doi.org/10.3390/fishes8030150 - 2 Mar 2023

Cited by 2 | Viewed by 1846

Abstract

The mitogenome is an important tool for researching the evolution of metazoan animals. However, until now, only few mitochondrial genes of Pseudorhombus pentophthalmus have been reported. Here, we report the complete mitogenome of P. pentophthalmus, assembled using the Illumina platform. The circular mitogenome [...] Read more.

The mitogenome is an important tool for researching the evolution of metazoan animals. However, until now, only few mitochondrial genes of Pseudorhombus pentophthalmus have been reported. Here, we report the complete mitogenome of P. pentophthalmus, assembled using the Illumina platform. The circular mitogenome of P. pentophthalmus is 16,684 bp in length, has a bias A+T content of 52.78%, encodes 37 genes (13 protein-coding genes, 22 tRNA genes, 2 rRNA genes), and has a control region. The overall nucleotide composition was A: 26.56%, T: 26.22%, G: 17.97%, and C: 29.25%. The phylogenetic tree based on the complete mitogenome P. pentophthalmus was shown to be monophyletic with the other Pseudorhombus species and was shown to be on the same branch as P. dupliciocellatus. This research might be useful for future studies on population genetics and evolution analysis. Full article

(This article belongs to the Section Taxonomy, Evolution, and Biogeography)

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12 pages, 2008 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Exposure of Hyalella bonariensis (Crustacea, Amphipoda) to Essential Oils: Effects on Anesthesia and Swimming Activity

by Alessandra Janaína Becker, Sandro Santos, Berta Maria Heinzmann, Braulio Otomar Caron and Bernardo Baldisserotto

Fishes 2023, 8(3), 149; https://doi.org/10.3390/fishes8030149 - 2 Mar 2023

Cited by 1 | Viewed by 2069

Abstract

Amphipods are frequently used as bioindicators of water quality in experimental or behavior trials. Thus, it is a group considered suitable for use as a model organism in tests with essential oils (EOs). This study evaluated the time required for anesthesia induction and [...] Read more.

Amphipods are frequently used as bioindicators of water quality in experimental or behavior trials. Thus, it is a group considered suitable for use as a model organism in tests with essential oils (EOs). This study evaluated the time required for anesthesia induction and recovery of the amphipod crustacean H. bonariensis exposed to the essential oils of Aloysia triphylla (EOAT) and Lippia alba (EOLA), and their major compounds citral and linalool, respectively. In addition, we evaluated the locomotor activity of amphipods using ANY-maze^® software. Mortalities were observed at concentrations of 100 and 200 µL/L of citral (50.0 ± 0.39%) and 750 µL/L of EOLA (66.7 ± 0.33%). Except for linalool, increased concentrations of the compounds of the essential oils decreased the time for sedation and anesthesia induction. There were differences for the induction of anesthesia (p < 0.05) and recovery (p < 0.05) between EOLA and linalool treatments, but not between that for EOAT and citral. Reduced locomotor activity and longer time and episodes of freezing were observed in animals exposed to EOAT. The EOs and their major compounds induced anesthesia and affected the locomotor activity of H. bonariensis, Therefore, EOAT and linalool are recommended for anesthesia of this species. EOAT can also be utilized in long-term exposure. Full article

(This article belongs to the Section Welfare, Health and Disease)

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Time required for anesthesia induction and recovery of the amphipod H. bonariensis exposed to L. alba EO (a), linalool (b), A. triphylla EO (c), and citral (d). Different lowercase letters above the bars indicate significant differences in the time required for anesthesia induction or recovery between concentrations for the same anesthetics or major compounds. Different uppercase letters indicate significant differences in the time required for anesthesia induction or recovery between the anesthetics and their major compounds (L. alba X linalool; A. triphylla X citral) (p < 0.05). Data are presented as mean ± SEM (n = 8). Full article ">Figure 2
Locomotor parameters and comparison between immobility periods observed in H. bonariensis groups during behavioral trial. Mean speed (a). Maximum speed (b). Absolute turning angle (c). Time of freezing (d). Freezing episodes (e). Different letters on the right side of the bars indicate significant differences between anesthetic concentrations (p < 0.05; by one-way ANOVA followed by Tukey’s or Kruskal–Wallis tests; n = 5 per group). Full article ">Figure 3
Tank exploration of H. bonariensis exposed to control, ethanol, and 75 µL/L of A. triphylla EO (EOAT). Concentrations of 50 and 75 µL/L of linalool and 100 and 200 µL/L of L. alba EO (EOLA). Distance (a). Line crossings (b). Different letters indicate significant difference in length of stay at the aquarium zones between the different treatments (p < 0.05; by one-way ANOVA followed by Tukey’s or Kruskal–Wallis tests; n = 5 per group). Full article ">Figure 3 Cont.
Tank exploration of H. bonariensis exposed to control, ethanol, and 75 µL/L of A. triphylla EO (EOAT). Concentrations of 50 and 75 µL/L of linalool and 100 and 200 µL/L of L. alba EO (EOLA). Distance (a). Line crossings (b). Different letters indicate significant difference in length of stay at the aquarium zones between the different treatments (p < 0.05; by one-way ANOVA followed by Tukey’s or Kruskal–Wallis tests; n = 5 per group). Full article ">Figure 4
Comparative analysis of the time spent in each zone of aquarium for the amphipod H. bonariensis during exposure to control, ethanol, and 75 µL/L of A. triphylla EO (EOAT). Concentrations of 50 and 75 µL/L of linalool and 100 and 200 µL/L of L. alba EO (EOLA). Full article ">

22 pages, 4606 KiB

Open AccessArticle

Comparison of Immune Response of Litopenaeus vannamei Shrimp Naturally Infected with Vibrio Species, and after Being Fed with Florfenicol

by Medhat S. Shakweer, Gehad E. Elshopakey, Abdelwahab A. Abdelwarith, Elsayed M. Younis, Simon John Davies and Samia Elbahnaswy

Fishes 2023, 8(3), 148; https://doi.org/10.3390/fishes8030148 - 2 Mar 2023

Cited by 7 | Viewed by 3662

Abstract

The outbreaks caused by Vibrio spp. are a notable threat to the potential growth of the economy of penaeid culture, which is still controlled by the administration of antibiotics. At first, the infected group was subjected to phenotypic bacteriological examination with subsequent molecular [...] Read more.

The outbreaks caused by Vibrio spp. are a notable threat to the potential growth of the economy of penaeid culture, which is still controlled by the administration of antibiotics. At first, the infected group was subjected to phenotypic bacteriological examination with subsequent molecular identification via 16S rRNA gene sequencing, which confirmed four strains of Vibrio spp., V. atlanticus, V. natriegens, V. alginolyticus, and V. harveyi, from moribund-infected shrimp during mortality events in an Egyptian hatchery. To better understand the defense mechanism of the most effective antibiotic against Vibrio strains, the immune responses were compared and evaluated in infected Litopenaeus vannamei broodstock after being fed 5 mg kg⁻¹ of florfenicol antibiotic, which was first determined through in vitro antibiogram tests. Therefore, our study aimed to determine the immune response of L. vannamei during Vibrio spp. infection in Egyptian hatcheries and after antibiotic medication. The parameters assessed were the total and differential hemocyte count (THC), granular cells (GC), semi-granular cells (SGC), and hyaline cells (HC). As well as the metabolic and immune enzymes: alanine aminotransferases (ALT), aspartate aminotransferases (AST), alkaline phosphatase (ALP), acid phosphatase (ACP), and lysozyme activity; an antioxidant index, such as superoxide dismutase (SOD) and glutathione (GSH); a phagocytic assay; changes in reactive oxygen species (ROS); and bactericidal activity in the hemolymph of the control, infected, and treated groups. Further evaluation of the mRNA expression levels of the prophenoloxidase (LvproPO), toll-like receptor 1 (LvToll1), and haemocyanin (LvHc) genes were performed in the hepatopancreas of the same groups. A significant drop in the THC, GC, SGC, and HC counts, as well as lysozyme and bactericidal activities, phagocytic assay, ROS, SOD, and GSH index, were represented in infected shrimp compared to control shrimp; however, a marked increase in the activity of ALT, AST, ALP, and ACP was observed. These activities were significantly restored in the treated shrimp compared to the infected shrimp. Nevertheless, no significant changes were noted in the transcriptional levels of the LvproPO and LvToll1 genes in the treated shrimp when compared to the infected shrimp; however, a significant suppression of the LvHc gene was noted. Our study aimed to determine the immune response of L. vannamei during Vibrio spp. infection in Egyptian hatcheries and after antibiotic medication. We concluded that florfenicol in medicated feed could be effective in controlling vibriosis and ameliorating the immune response of shrimp. Full article

(This article belongs to the Section Nutrition and Feeding)

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19 pages, 12517 KiB

Open AccessArticle

Beneficial Effects of Graded Levels of Fish Protein Hydrolysate (FPH) on the Growth Performance, Blood Biochemistry, Liver and Intestinal Health, Economics Efficiency, and Disease Resistance to Aeromonas hydrophila of Pabda (Ompok pabda) Fingerling

by Afrina Yeasmin Suma, Shishir Kumar Nandi, Zulhisyam Abdul Kari, Khang Wen Goh, Lee Seong Wei, Albaris B. Tahiluddin, Paul Seguin, Mikael Herault, Abdullah Al Mamun, Guillermo Téllez-Isaías and Muhammad Anamul Kabir

Fishes 2023, 8(3), 147; https://doi.org/10.3390/fishes8030147 - 2 Mar 2023

Cited by 20 | Viewed by 4869

Abstract

Fish protein hydrolysate (FPH) is the enzymatic hydrolysis of protein into smaller peptide and free amino acids, which has recently captured considerable attention as a supplementary ingredient in the aqua-feed industry sector. The present research aimed to observe the physiological, biochemical, and bacteriological [...] Read more.

Fish protein hydrolysate (FPH) is the enzymatic hydrolysis of protein into smaller peptide and free amino acids, which has recently captured considerable attention as a supplementary ingredient in the aqua-feed industry sector. The present research aimed to observe the physiological, biochemical, and bacteriological study of FPH-treated diets and its effects on growth, hematology, plasma biochemistry, liver and gut histopathology, and resistance to Aeromonas hydrophila infection in Pabda (Ompok pabda). Four experimental diets (35% crude protein) were formulated with graded FPH supplementation (0, 0.5, 1, and 2%). The feed physiological parameters such as expansion ratio, bulk density, water stability, and floatability were not significantly affected by dietary FPH levels (p > 0.05), except for the pellet durability index (PDI). Furthermore, the diets with 1% and 2% FPH were more palatable to fish than other treatment diets. The total bacteria (TB) in fish diets and guts followed an increasing trend with the increase in various levels of FPH in diets. The significantly highest body weight, specific growth rate (SGR), total biomass (TB), survival rate (SR), condition factor (CF), and hepatosomatic index (HSI) were noted in 2% FPH-fed fish when compared with other treatment groups (p < 0.05). The feed intake of fish was significantly increased when increasing the FPH in diets (p < 0.05). The fish fed with a 2% FPH diet had significantly higher neutrophil, monocyte, lymphocyte, red blood cell, and platelet levels (p < 0.05). The blood glucose, creatinine, total protein, and globulin were significantly lower in control fish compared to other treatment groups (p < 0.05). The histopathological observation of mid intestine tissues displayed that 2% of FPH-diet-fed fish had a well-anchored epithelial wall with well-arranged goblet cells, a long villus structure, stratum compactum, and tunica muscularis compared to other treatments of FPH. The inclusion of FPH in diets up to 2% significantly improved the liver health of fish. The fish fed with 2% FPH had a significantly lower cumulative percent mortality (16.67%) against A. hydrophila infection in the bacterial challenge test (p < 0.05). Therefore, the present results suggested that using 2% FPH in the aqua-feed industry improves the growth performance, health status, and disease resistance of Pabda fingerlings in captivity. Full article

(This article belongs to the Special Issue Feed and Nutrition Research in Aquaculture)

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3 pages, 186 KiB

Open AccessEditorial

Fish Nutrition and Feed Technology

by Marina Paolucci

Fishes 2023, 8(3), 146; https://doi.org/10.3390/fishes8030146 - 28 Feb 2023

Cited by 1 | Viewed by 3997

Abstract

This Special Issue was designed to address advances in feeding and feed technology and challenges in aquaculture in order to achieve a greater understanding of its management and improve the sector [...] Full article

(This article belongs to the Special Issue Fish Nutrition and Feed Technology)

18 pages, 6685 KiB

Open AccessArticle

Comparative Transcriptome Analysis Identifies MAPK Signaling Pathway Associated with Regulating Ovarian Lipid Metabolism during Vitellogenesis in the Mud Crab, Scylla paramamosain

by Yuanhao Ren, Wei Wang, Yin Fu, Zhiqiang Liu, Ming Zhao, Likun Xu, Tianyong Zhan, Ting Huang, Minghao Luo, Wei Chen, Chunyan Ma, Fengying Zhang, Keji Jiang and Lingbo Ma

Fishes 2023, 8(3), 145; https://doi.org/10.3390/fishes8030145 - 28 Feb 2023

Cited by 5 | Viewed by 2400

Abstract

The mud crab, Scylla paramamosain, has abundant nutrients in the ovary, where numerous lipids accumulate during ovarian maturation. However, the mechanism behind the accumulation of lipids in the ovary of mud crab during ovarian maturation is largely unknown. This study conducted a [...] Read more.

The mud crab, Scylla paramamosain, has abundant nutrients in the ovary, where numerous lipids accumulate during ovarian maturation. However, the mechanism behind the accumulation of lipids in the ovary of mud crab during ovarian maturation is largely unknown. This study conducted a comparative transcriptome analysis of the ovaries of mud crabs at various stages of ovarian maturation. A total of 63.69 Gb of clean data was obtained, with a Q30 of 93.34%, and 81,893 unigenes were identified, including 10,996 differentially expressed genes (DEGs). After KEGG enrichment of these DEGs, MAPK signaling pathway was significantly enriched during vitellogenesis. Moreover, the expression levels of genes involved in carbohydrate, amino acid, and lipid metabolism were found to be higher during vitellogenesis. The two genes (Sp-Eip75B and Sp-Eip78C) that are homologous to the vertebrate gene PPARγ in the PPAR signaling pathway, were identified. Additionally, genes in MAPK signaling pathway might regulate lipid metabolism through PPAR signaling pathway based on Protein-Protein Interaction (PPI) network. These findings suggest that MAPK signaling pathway plays a critical role in lipid metabolism in the ovary during vitellogenesis, which provides new insights into the mechanism of lipid accumulation during ovarian maturation in mud crabs. Full article

(This article belongs to the Special Issue Recent Advances in Crab Aquaculture)

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(A) Distribution of the length of unigenes and transcripts. The abscissa represents different length ranges of transcripts and unigenes, and the ordinate represents the number of transcripts and unigenes in a certain length range. (B) Functional annotation of unigenes from six databases (GO, KEGG, eggNOG, NR, Swiss-Prot, and Pfam). Full article ">Figure 2
Annotation of the unigenes obtained from the transcriptome assembly of S. paramamosain. (A) Venn diagram of the total unigenes annotated into the six databases (NR, Siwss-Prot, Pfam, eggNOG, GO, and KEGG), the central white part is the number of common genes. (B) GO annotation results are summarized into three main categories (biological process, cellular component, and molecular function). (C) eggNOG annotation of the total unigenes; the results are classified into 23 categories. (D) KEGG annotation of the total unigenes are assigned into four main categories (metabolism, genetic information processing, environmental information processing, and cellular process). Full article ">Figure 3
qRT-PCR validation of the DEGs from the transcriptome sequencing. The sample information represented by abscissa (see <a href="#fishes-08-00145-t001" class="html-table">Table 1</a>) and the ordinate represents the gene relative expression level of qRT-PCR and transcriptome sequencing (TPM). A total of 6 genes were validated (A) gene 1, (B) gene 2, (C) gene 3, (D) gene 4, (E) gene 5, (F) gene 6, (G) Sp-Vg, and (H) Sp-VgR. All the information about the genes in the qRT-PCR are listed in the <a href="#app1-fishes-08-00145" class="html-app">Supplementary File Table S1</a>. Different superscript letters in the column of the figures indicate a significant difference (p < 0.05). Full article ">Figure 4
Annotation of the DEGs in the GO and KEGG databases. (A) The number of DEGs in the different comparison groups. (B) Venn diagram of the DEGs from different comparison groups. (C) GO annotation of total DEGs. (D) KEGG annotation of total DEGs. Full article ">Figure 5
Heatmap analysis of the expression of metabolism-related genes during different ovarian stages. KEGG analysis of three metabolic pathway unigenes of up- and down-regulated during different ovarian stages: (A) Carbohydrate metabolism; (B) Amino acid metabolism; (C) Lipid metabolism. GO analysis of lipid metabolism-related genes up- and down-regulated during different ovarian stages: (D) Lipid metabolic process (GO: 0006629); (E) Lipid binding (GO: 0008289); (F) Lipid biosynthetic process (GO: 0008610). KEGG analysis of three lipid metabolism pathway genes of up- and down-regulated during different ovarian stages: (G) Fatty acid degradation (map00071). Full article ">Figure 6
KEGG enrichment of DEGs in the different comparison groups. (A) Total number of DEGs in the vitellogenesis stages of SOMP (S_OV_4_vs_S_OV_3; S_OV_5_vs_S_OV_4); (B) Total number of DEGs in the vitellogenesis of FOMP (F_OV_4_vs_F_OV_3; F_OV_5_vs_F_OV_4); (C) Total number of DEGs in the comparison groups between the SOMP and FOMP during vitellogenesis (S_OV_3_vs_F_OV_3; S_OV_4_vs_F_OV_4; S_OV_5_vs_F_OV_5); (D) PPAR signaling pathway; (E) MAPK signaling pathway. Full article ">Figure 7
Domain architectures of the PPARγ-homologs, Eip75B and Eip 78C, in Drosophila melanogaster and S. paramamosain. Sp-Eip75B/78C: ecdysone-induced protein E75B/78C in S. paramamosain; Dm-Eip75B/78C: ecdysone-induced protein E75B/E78C in Drosophila melanogaster. NR_LBD: Ligand-binding domain (LBD) of nuclear receptor (NR); NR_DBD: DNA binding domain (DBD) of nuclear receptor (NR). Full article ">Figure 8
Protein-protein interaction network of MAPK and PPAR signaling pathways. All the information of the proteins in the network are listed in the <a href="#app1-fishes-08-00145" class="html-app">Supplementary File Table S5</a>. Full article ">Figure 9
Schematic diagram of hypothetical mechanism of several key signaling pathways regulating lipid metabolism in S. paramamosain. Full article ">

15 pages, 5030 KiB

Open AccessArticle

Two Probiotic Candidates of the Genus Psychrobacter Modulate the Immune Response and Disease Resistance after Experimental Infection in Turbot (Scophthalmus maximus, Linnaeus 1758)

by Sven Wuertz, Filipa Beça, Eva Kreuz, Konrad M. Wanka, Rita Azeredo, Marina Machado and Benjamin Costas

Fishes 2023, 8(3), 144; https://doi.org/10.3390/fishes8030144 - 28 Feb 2023

Cited by 10 | Viewed by 3087

Abstract

Probiotic bacteria are a recognized alternative to classical methods of disease prophylaxis and therapy. We tested the effects of their application on the immune reaction in juvenile turbot. To prevent digestion of the probiotics, rectal administration was applied to maximise colonization, by-passing digestion [...] Read more.

Probiotic bacteria are a recognized alternative to classical methods of disease prophylaxis and therapy. We tested the effects of their application on the immune reaction in juvenile turbot. To prevent digestion of the probiotics, rectal administration was applied to maximise colonization, by-passing digestion in the stomach. The application of Psychrobacter nivimaris and Psychrobacter faecalis showed beneficial effects on the inflammatory response and disease resistance after infection with the common pathogen Tenacibaculum maritimum. Treatment with P. nivimaris and P. faecalis resulted in 0% and 8% mortalities post-infection, while in the treatment control, an elevated mortality of 20% was observed. In the challenge controls (no infection), no mortalities were observed during the entire experimental period. After an experimental infection, mRNA expression of selected immune markers (mhc II α, il-1β, tcr, tgf β and tnf α) were determined by RT-QPCR at 0, 1 and 5 days post-infection (dpi). At 0 dpi, gene expression was comparable between the treatments and the treatment control, suggesting that probiotics did not act via immune stimulation of the host. At 1 dpi, all genes were up-regulated in the treatment control but not in the probiotic groups, indicating that the infection in probiotic-treated fish developed at a less severe level. At 5 dpi, mRNA expression returned to baseline levels. As a conclusion, the native probiotic candidates P. nivimaris and P. faecalis improved survival, whereas, in the control, mortality increased and expression of the immune markers was up-regulated post infection. This highlights a potential application of P. nivimaris and P. faecalis in disease prophylaxis, but further research is needed. Full article

(This article belongs to the Special Issue Nutrition and Immunity of Fish and Shellfish)

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15 pages, 3603 KiB

Open AccessArticle

Design and Study of a Spindle-Shaped Fry Head-to-Tail Orientation Device

by Jianping Li, Chen Li, Congcong Li, Wei Luo, Kang Wu, Songming Zhu and Zhangying Ye

Fishes 2023, 8(3), 143; https://doi.org/10.3390/fishes8030143 - 28 Feb 2023

Viewed by 1783

Abstract

The head-to-tail orientation of spindle-shaped fry is an important part of automated vaccine injection. The fry’s automatic orientation helps reduce labor and improve efficiency during the automated injection. This paper designed an electromagnetic vibration fry orientation device for grass carp fry, measured its [...] Read more.

The head-to-tail orientation of spindle-shaped fry is an important part of automated vaccine injection. The fry’s automatic orientation helps reduce labor and improve efficiency during the automated injection. This paper designed an electromagnetic vibration fry orientation device for grass carp fry, measured its friction characteristics with three different materials in scales and against scales, analyzed the kinematic characteristics of the fry on the electromagnetic vibration feeder, and clarified the main factors affecting fry transport. It used the trough’s inclination angle, amplitude, and material as the test factors, whereas the orientation success rate and orientation rate were used as the evaluation index. Orthogonal combination tests were carried out with 90–150 mm grass carp fry as the research object to obtain reasonable parameter combinations. The results showed that the best orientation effect was achieved when the surface of the trough was a silicone film with many bumps, the inclination of the plate spring was β = 15°, the inclination of the trough plane was θ_y = −4°, and the amplitude A = 0.7 mm. In this parameter combination, the directional device was tested and verified. The targeted success rate was ε = 95.5%, and the direction rate was η = 0.87 tail/s. The device could meet the requirements of the head and tails during the mechanized injection of the fry. Full article

(This article belongs to the Section Fishery Facilities, Equipment, and Information Technology)

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10 pages, 573 KiB

Open AccessArticle

Improvement of Flesh Quality of Farmed Silver Carp (Hypophthalmichthys molitrix) by Short-Term Stocked in Natural Water

by Xiaomin Miao, Hui Guo, Yong Song, Chunying Du, Jingyun Feng, Yixi Tao, Hao Xu and Yun Li

Fishes 2023, 8(3), 142; https://doi.org/10.3390/fishes8030142 - 28 Feb 2023

Cited by 4 | Viewed by 2024

Abstract

To investigate the effects of different raising environments on the flesh quality, the study set up three groups of silver carp (Hypophthalmichthys molitrix), that is, pond-farmed; short-term stocked; and ranched, grown in a natural water ranch. This study compared the differences [...] Read more.

To investigate the effects of different raising environments on the flesh quality, the study set up three groups of silver carp (Hypophthalmichthys molitrix), that is, pond-farmed; short-term stocked; and ranched, grown in a natural water ranch. This study compared the differences in muscle proximate composition and amino acid composition among three groups. The results showed that there was no difference between the ranched and the stocked groups in content of crude protein, ash, total amino acids (TAA), essential amino acids (EAA), and umami-flavored amino acids (UAA), with both groups being significantly higher than the farmed group. This shows that, in terms of flesh quality, the stocked group was closer to the ranched group and better than the farmed group after being stocked in natural water for 30 days. The results suggest that the flesh quality of farmed fish was improved by short-term stocking in natural water. To elucidate the reasons of flesh quality change in the stocked group, this study compared the food composition and intestinal digestive enzyme activity in three groups, demonstrating that the ranched and stocked groups had similar food composition, with their detritus proportion lower than that of the farmed group, consuming easily digestible phytoplankton diatoms rich in amino acids and fatty acids. No significant difference was seen between the ranched group and the stocked group, for which amylase, lipase, and trypsin activities were lower than that of the farmed group. It is hypothesized that differences in environmental and food composition resulted in lower digestive enzyme activity in the ranched group and the stocked group. In summary, the short-term stocking of farmed fish in a natural water ranch can effectively improve the nutrient content, quality and flavor, and promote value of fish products. Full article

(This article belongs to the Section Sustainable Aquaculture)

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12 pages, 310 KiB

Open AccessArticle

Dietary Tryptophan Supplementation Implications on Performance, Plasma Metabolites, and Amino Acid Catabolism Enzymes in Meagre (Argyrosomus regius)

by Cláudia Teixeira, Rita Pedrosa, Carolina Castro, Rui Magalhães, Elisabete Matos, Aires Oliva-Teles, Helena Peres and Amalia Pérez-Jiménez

Fishes 2023, 8(3), 141; https://doi.org/10.3390/fishes8030141 - 28 Feb 2023

Cited by 3 | Viewed by 3129

Abstract

Tryptophan (Trp) is an essential amino acid, commercially available as a feed-grade product, and is a precursor to serotonin and melatonin, which are both important molecules in stress mitigation. Meagre have a high potential for marine aquaculture diversification but are highly susceptible to [...] Read more.

Tryptophan (Trp) is an essential amino acid, commercially available as a feed-grade product, and is a precursor to serotonin and melatonin, which are both important molecules in stress mitigation. Meagre have a high potential for marine aquaculture diversification but are highly susceptible to stressful conditions. This study aimed to assess the potential role of dietary tryptophan supplementation in meagre juveniles in order to minimize the deleterious effect of potential stress conditions. For this, a growth trial was performed wherein meagre juveniles were fed four isoproteic (45%DM) and isolipidic (16%DM) diets; namely, a control diet, and three diets similar to the control diet but supplemented with varying levels of tryptophan, graded according to the resulting percentage in each diet’s dry matter (Control, 0.25%Trp, 0.5%Trp, and 1%Trp), corresponding to a total dietary tryptophan of 1.06, 1.70, 2.08, and 3.24 g 16 g⁻¹ N, respectively. Diets were tested in triplicate, and fish were fed twice a day, six days a week, for eight weeks. Five days after the end of the growth trial, a time-course blood sampling was performed at 0 h, 1 h, 3 h, 6 h, and 12 h after feeding. At the 6 h sampling point, the liver was also collected. Overall, our results indicate that 1Trp supplementation (total dietary Trp 3.24 g 16 g⁻¹ N) may be harmful to fish, decreasing growth performance and feed utilization, although doses up to 0.5Trp do not influence these parameters. Voluntary feed intake lineally decreased with the increase in the level of dietary Trp. Whole-body lipid content decreased at the highest tryptophan inclusion, whereas no changes were observed in protein levels. After 12 h from feeding, plasma glucose levels were lower in all dietary treatments supplemented with tryptophan compared to those observed in the control. Hepatic enzyme activity of protein catabolism decreased with dietary Trp inclusion. Overall, our results suggested that while a dietary Trp level increase of up to 2.08 g 16 g⁻¹ N did not affect growth performance and feed efficiency, both these parameters were severely compromised with a Trp level of 3.24 g 16 g⁻¹ N. Full article

(This article belongs to the Special Issue Women’s Special Issue Series: Their Contribution to Aquatic Animals Study)

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Fishes, Volume 8, Issue 3 (March 2023) – 50 articles

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