Herpetology Notes, volume 8: 315-320 (2015) (published online on 19 May 2015)
First report of the reproduction in captivity of the Chocoan
Bushmaster, Lachesis acrochorda (García, 1896)
Ana María Henao Duque1,* and Greivin Corrales2
Abstract. The Serpentarium at the Universidad de Antioquia houses four specimens of the Chocoan bushmaster (Lachesis
acrochorda) in a vivarium simulating natural habitat conditions. After an acclimatization period of nine months the moisture
level in the enclosure was increased artificially to induce reproductive behaviour. One male was observed to court a female
for 15 days, but copulation was not observed. The female subsequently refused food and 110 days after the last observation
of courting 11 eggs (average weight 57.9 g) were discovered. While three eggs were artificially incubated, the rest were left
in the vivarium; both sites were monitored continuously. On Day 74 of incubation, the eggs in the vivarium were moved to
an incubator due to a drop in temperature. Hatching began on Day 93 and seven eggs hatched during a 3-day period. Average
weight (42.0 ± 3.6 g) and length (40.0 ± 1.4 cm) of the neonates was recorded. This is the first report of captive reproduction
for L. acrochorda.
Keywords. Courtship behaviour, eggs, hatchling, pitviper, vivarium, Lachesis acrochorda, Colombia, bushmaster.
Resumen. El Serpentario de la Universidad de Antioquia alberga cuatro verrugosos (Lachesis acrochorda) en un vivario
que simula las condiciones naturales de su hábitat. Después de un período de aclimatación de nueve meses, se incrementaron
los niveles de humedad en el encierro mediante aumento en la frecuencia del riego, con el fin de inducir el comportamiento
reproductivo. Posteriormente se observó el cortejo de un macho a una de las hembras durante 15 días, no obstante no se
observó la cópula. La hembra dejó de alimentarse durante las alimentaciones subsecuentes y 110 días después del último
día de cortejo se encontró enrollada sobre 11 huevos (peso promedio 57.9 g). Tres huevos se incubaron artificialmente y los
demás se dejaron en el vivario, ambos se monitoreaban continuamente. Al Día 74 de incubación los huevos que se dejaron
en el vivario se trasladaron a incubación artificial, debido a una caída en la temperatura. La eclosión empezó el Día 93 y siete
huevos eclosionaron durante un período de tres días. Los neonatos se midieron (40.0 ± 1.4 cm) y pesaron (42.0 ± 3.6 g). Este
es el primer reporte de la reproducción de Lachesis acrochorda en cautiverio.
Palabras clave. Cortejo, huevos, eclosión, víbora de foseta, vivario, Lachesis acrochorda, Colombia, verrugoso
Introduction
Vipers of the genus Lachesis, commonly known
as bushmasters, or verrugosos in Colombia, are the
longest members of the family Viperidae (de Souza,
2007). As currently recognized, there are four species
of bushmasters, two in Central America, L. stenophrys
(Cope, 1876) and L. melanocephala (Solórzano and
Cerdas, 1986), and two in South America, L. acrochorda
(García, 1889) and L. muta (Linnaeus, 1766); the latter
is an Amazonian taxon comprising two subspecies, L. m.
muta and L. m. rhombeata (Wied, 1824). Zamudio and
Greene (1997) confirmed this taxonomic arrangement
using mitochondrial DNA data. These snakes have
specialized habitats and are found almost exclusively
in primary forest, which makes nearly inaccessible to
humans and difficult to find. Their diet usually consists of
small mammals, which makes them selective predators
1
Ophidism/Scorpionism Program, Universidad de Antioquia
UdeA, Calle 70 No. 52-21, Medellín, Colombia
2
La Ceiba Biological Reserve, Punta Uva, Costa Rica
* Corresponding author: ana.h.cat@gmail.com
316
Ana María Henao Duque & Greivin Corrales
(Campbell and Lamar, 2004). Additionally, they are
oviparous vipers, depositing their eggs in underground
cavities or the burrows of other animals (Ripa, 1994;
Campbell and Lamar, 2004; de Souza, 2007).
Natural History of Lachesis acrochorda.—Lachesis
acrochorda is a large snake (Ripa, 2001; Campbell and
Lamar, 2004), reaching up to 3 m in total length (TL).
It is characterized by an arabesque colour pattern on
the head, a ventral scale count intermediate between L.
stenophrys and L. muta, as well as a variety of additional
distinguishing features (Ripa, 1999, 2001). Its preferred
habitat is tropical wet forest from sea level up to 1000
m (Ripa, 1999; Campbell and Lamar, 2004). Lachesis
acrochorda is distributed in Panamá, Colombia, and
Ecuador. In Colombia populations exist along the
northwestern Atlantic Coast, along the Pacific Coast and
to the south of Antioquia and Caldas in the valleys of
the Magdalena and Cauca rivers (Campbell and Lamar,
2004). Although this species is found in remote areas
and primary forest, the fragmentation and destruction
of their natural habitat and the largely negative reaction
of humans to venomous snakes impacts the population.
In addition, it is known that bushmasters do not easily
adapt to climatic variations caused by deforestation (Vial
and Jimenez-Porras, 1967; Ripa, 1994, 1999). For these
conservation-oriented reasons, but more importantly
to produce antivenom, it is important to maintain and
propagate these species in captivity.
Maintaining bushmasters in captivity poses a significant
challenge because they are very susceptible to stress,
may refuse to feed, and can suffer from maladaptation
syndrome (Turner et al., 2008). Simulating their natural
environment, absent the stress that arrives with human
interactions in the form of keepers, is hard to accomplish,
but their reproduction depends on the conditions in
which these animals are housed to be optimal and free
from stress (Dowling, 1960; Burchfield, 1975; Boyer,
1989; Ripa, 1994, 1999; Turner et al., 2008). Successful
captive reproduction has been reported previously for
three species of Lachesis: Ripa (1994) reported on L.
stenophrys and L. melanocephala, and Boyer et al.
(1989) and de Souza (2007) on L. muta, the latter on the
subspecies L. m. rhombeata. The junior author recently
participated in a study of L. stenophrys in Costa Rica,
where successful reproduction occurred (Corrales et al.,
2014).
The aim of this report is to describe the reproduction
of L. acrochorda in captivity, including the process of
gestation, oviposition, and hatching of eggs and the
growth of the neonates. To the best of our knowledge,
this is the first time captive breeding was achieved for
this species.
Materials and Methods
Specimens.—Four wild-caught adult specimens (2M,
2F) were donated from E.S.E. Hospital Maria Toro de
Elejalde (Frontino) and E.S.E. Hospital San Camilo de
Lelis (Vegachí) to the Serpentarium at the Universidad
de Antioquia (Medellín, Colombia) between 2007 and
2013 (Table 1). They were collected at La Blanquita,
Frontino, Western Antioquia, Colombia (6°45’00” N,
76°18’00’’ W) and Las Águilas, Vegachí, Northeast
Antioquia, Colombia (6°46’23’’ N, 74°48’06’’ W).
Initial Preparation.—Each specimen was assigned
a collection number (e.g., M1 = male No. 4074, F2 =
female No. 4230), weighed, measured, and sexed. They
were housed in individual boxes and maintained in the
environmental conditions of Medellín, Colombia, with
a temperature between 16–28°C and relative humidity
between 50–65% (IDEAM, 2005). Snakes remained in
quarantine for a period of 90 days, during which they
were under constant veterinary supervision. They were
dewormed based on the results from stool sampling.
Table 1. Descriptions for the four individuals of Lachesis acrochorda used in this study. Specimen numbers indicate sex (M =
male, F = female) and breeding attempt (*).
indicate sex (M = male, F = female) and breeding attempt (*).
Sex
Length (cm)
Weight (g)
Origin
Time in captivity
M1*
243
4706
Vegachí
5 yr
F1*
168
2569
Frontino
1 yr
M2
154
1483
Frontino
10 mo
F2
162
1859
Frontino
4 mo
First report of the reproduction in captivity of the Chocoan Bushmaster
317
every day. No cameras were used. Results from all
observations were compiled and evaluated.
Results
Figure 1. Lachesis acrochorda female, specimen F1, coiled
around her eggs. Photo by Ana M. Henao
Establishment.—At the end of the quarantine period,
the animals were moved to an enclosure with length,
width, and height dimensions of 3.58 m x 2.51 m x
2.67 m, respectively. The enclosure had a filter-covered
drain and a substrate composed of gravel, soil, and rice
husks. It included four shelters constructed from roots
and tree trunks, a source of water with 40-liter capacity,
larger rocks, plants (Araceae, Cannaceae, Ciclantaceae),
controlled irrigation twice weekly, a temperature
between 19 and 28°C, and relative humidity of 75–
95%, all of which simulates the natural habitat of this
species.
General maintenance.—Once the animals were
established in their enclosure, they fed voluntarily and
no dysecdysis was observed. Every 20 days prey was
offered, consisting of guinea pigs (Cavia porcellus) and
rabbits (Oryctolagus cuniculus), each weighing 90–180
g. Prey animals were delivered alive using hooks, and
were presented individually to snakes according to body
size.
Stimulation.—Several authors described that a sudden
drop in temperature (Boyer et al., 1989; Ripa, 2001; de
Souza, 2007) and an increase in humidity can induce
reproductive behaviour in bushmasters (Ripa, 1994).
For this reason, the watering frequency was increased
to three times weekly in February 2013 so that humidity
could be maintained above 85%. At this time the four
specimens were housed together in the enclosure.
Observations.—Animal behaviour was directly
observed during three 20-min observation periods
Courtship Behaviour.—During the first days of June
2013, we observed M1 engaging in courtship behaviour
with F1. This consisted of using its head to rub scales
against and gently tap the head and neck of F1, while
she was coiled. Courtship began on 6 June after 1600
hrs and was also recorded on 15 consecutive days. No
copulation was observed. Courtship was intermittent
and always started in the afternoon. During the courtship
period, which included the time when mating must have
occurred, all animals continued to feed voluntarily. M1
never courted F2, and M2 never showed any courtship
behaviour because it was still sexually immature.
Gravidity and Oviposition.—Beginning in early July
F1 refused to eat, which we suspect indicated that she
was gravid. About one week before we found eggs, F1
began to move actively around the vivarium using several
different places to rest. On 23 September 2013, ca. 110
days after having observed the last courtship behaviour,
F1 was found coiled around 11 eggs (Fig. 1). During
the entire next day, F1 remained beside the clutch. Four
days later, we attempted to remove the eggs from the
vivarium following the recommendations of Boyer et
al. (1989), to avoid the potential loss of the eggs if there
was a problem with the incubation conditions. However,
only the three eggs on the periphery could be extracted
singly since the others were adhering to each other in an
underground cavity; this made their intact removal oneby-one impossible. These eggs were therefore left in the
vivarium under the previously described conditions to
avoid any breakage (Fig. 2).
Eggs and Incubation.—The extracted eggs weighed
on average 57.9 g and were kept in 1:1 vermiculite :
sterile water. The three extracted eggs were incubated
at 24.6–25°C temperature and 77.1–80.1% relative
humidity. However, none of the three eggs hatched.
The characteristics that identified these eggs as
non-developing included the presence of wrinkles,
compressions, and hardening after 22, 81, and 85
incubation days, respectively. Dissection revealed
a reddish spot of what appeared to be the embryo,
surrounded by caseous yolk.
The eggs that incubated under more natural conditions
in the vivarium did not experience changes in
incubation condition and were monitored twice daily.
The temperature ranged from 21.3–27.1°C and relative
humidity from 78.7–95.6%. Due to low temperatures
318
Ana María Henao Duque & Greivin Corrales
first shed their skin. We established the initial feeding
frequency at every ten days, and the amount of food
was determined based on 10% of the body weight for
each neonate. At the time of this writing, one year after
hatching, all neonates are feeding voluntarily.
Discussion
Figure 2. Eggs left in the vivarium. Photo by Ana M. Henao.
around 20°C for a one-week period in Medellín, on
Day 74 of incubation, the eight adhering eggs were
excavated and moved as a unit into an incubator (Model
12-140, Quincy Lab Inc., Chicago, Illinois, USA), in
order to provide optimal temperature conditions for
the development of the embryos. In the incubator, the
temperature remained between 24.5 and 27.7°C, and
relative humidity between 78.0 and 91.4%.
Hatching and Post-Hatching.—On Day 93 of
incubation (24 December 2013) hatching began and
lasted until Day 96. Seven of the neonates hatched
in good health (Table 2), but the eighth never fully
emerged from the egg.
Hatchlings had an average size and weight of 40.0 ±
1.4 cm and 42.0 ± 3.6 g. The first food, consisting of
pinky mice (4-day olds), was offered after hatchlings
F1 arrived at TL 168 cm and reproduced a year later,
whereas F2 arrived at TL 162 cm, just four months earlier
and was not courted by M1 (Table 1). Our observations
indicate that courtship behaviour occurred only between
M1 and F1. Sexual maturity for L. stenophrys and L.
melanocephala were described by Ripa (1999, 2001),
as early as 4 yrs of age for females and 3 yrs of age for
males in optimal conditions (with one male performing
courtship at 2.5 yrs). Ripa (1999, 2001) noted that these
early breeding episodes were not always successful
and might contribute to injury of the female. Solórzano
(2004) and Corrales et al. (2014) reported sexual maturity
at age 5 yrs in captivity for L. stenophrys, and that a
female of that age may present with a total length of
160 cm. At our facility, M1 courted and copulated with
F1 but not with F2, even though the difference in TL
between the females was only 6 cm. While we cannot be
certain, the absence of any reproductive advances of M1
on F2 could be a sign that F2 had not yet reached sexual
maturity. With sexual maturity in Lachesis occurring
near a TL of 160 cm, our F2 of L. acrochorda may have
not have reached the critical size for L. acrochorda.
On the other hand, given its small size, we are almost
certain that M2 was immature. Multiple matings, as
described by Ripa (1994), were therefore not possible
and not observed.
Courtship behaviour observed was consistent with
that described by Ripa (1994). This behaviour matches
Table 2. Time of hatching, length, and weight at birth of eight neonate Lachesis acrochorda.
Table 2. Time of hatching, length, and weight at birth of eight neonate Lachesis acrochorda.
Duration of incubation (days)
Total Length (cm)
Weight (g)
93
41,4
43,3
93
39,9
40,6
93
39,5
42,5
94
40,6
47,5
94
39,6
42,8
94
40
45,4
94
40,8
38
96
40
36,3
First report of the reproduction in captivity of the Chocoan Bushmaster
the experience of the junior author with L. m. muta and
L. stenophrys, namely a beginning of courtship by the
male without initial female response, followed after
several attempts by the male suddenly beginning to rub
the female, and coiling its tail around the last third of
her body in order to stimulate the cloacal area (Corrales
et al., 2014).
Regarding the oviposition behaviour of Lachesis
species, Ripa (1994) described that the gravid female
explores the site in order to find a place that ensures
adequate humidity and temperature and that allows her
to coil up completely around her eggs. Such behaviour
has been reported both ex situ and in situ (Ripa, 1994).
It has also been reported that in the wild L. acrochorda
uses burrows of “guagua in Colombia” (Agouti paca)
and armadillos (Dasypus sp.) to oviposit (Ripa, 1994;
De Souza, 2007). In our case the female oviposited in
a small underground cavity created with a root of a tree
and remained next to the eggs during the first four days
of incubation.
During the “natural” incubation of eggs in the vivarium,
F1 did not remain beside the eggs but changed her place
of rest frequently, in contrast to the behaviour reported
by Ripa (1994) for L. melanocephala and L. stenophrys,
species known to provide significant parental care for
their eggs. Additionally, F1 never showed aggressive
behaviour when the keeper entered the enclosure to
assess the state of the eggs. In comparison with the
incubation time reported for other bushmasters at 74–79
days (Switak, 1969; Boyer et al., 1989; Ripa, 1994, 1999;
319
de Souza, 2007; Corrales et al., 2014), the 96-day period
of incubation may be due to the incubation temperature
in the “natural” vivarium not being constant and at
times below 24°C, possibly the minimum incubation
temperature for successful development (Ripa, 1999,
2001; de Souza 2007). However, Solórzano (2004)
and Chacón and Valverde (2004) reported hatching
periods for Lachesis between 75–90 and 105–108 days,
respectively.
Eggs size in bushmasters varies considerably,
correlating with clutch size as well as the size and
nutritional status of the mother (Ripa, 1999, 2001).
It was reported previously that the average weight of
the eggs of a clutch of L. stenophrys (n = 16) and L.
melanocephala (n = 22) were 82.0 ± 0.2 g and 75.0 g,
respectively (Ripa, 1994; Corrales et al., 2014), which
are heavier than that deposited by the female of L.
acrochorda (57.9 g). The smaller egg size can perhaps
be attributed to the age of F1, who, based on her length,
is a young female; her exact age could not be confirmed
since the animal was not born in captivity.
The death of three eggs extracted on the fourth day
could be linked to the low humidity of incubation (77.1–
80.1%), consistent with that reported by de Souza (2007).
Successful incubation conditions are probably similar to
those of the rainforest, with a temperature range of 25–
28°C and relative humidity of 80–95%. Based on our
experience, we do not recommended separating the eggs
once they are adhered together in order to avoid trauma
or injury that may prevent successful hatching. In this
Figure 3. (Left) Overview of the vivarium at the Serpentarium of the Universidad de Antioquia (Medellín, Colombia) where a pair
of bushmasters (Lachesis acrochorda) was successfully captive-bred. (Right) Detail of the vivarium, showing one of the mated
individuals (M1) on the trunk. Photos by Ana M. Henao.
320
case, the eggs that were left in the place selected by F1
for the first 74 days of incubation hatched successfully,
as the cavity maintained adequate humidity, preventing
them from crinkling or compacting. Finally, with regard
to the death of the last neonate, we presume that this
could be from exhaustion, which was previously
reported by Mader (2006).
An important aspect for the captive breeding of this
species is to provide large spaces that simulate the
conditions of their natural habitat (Ripa, 1994, 1999; de
Souza, 2007). We believe that the successful reproduction
of L. acrochorda was facilitated by the construction and
adaption of an enclosure at the Serpentarium of the
Universidad de Antioquia (Medellín) that simulated the
conditions of their natural habitat (Fig. 3). This is the
first report of reproduction of this species in captivity.
Acknowledgements. The authors thank Jorge Enrique Asprilla
for his work and collaboration in the care of the snakes for so
many years, as well as for his support in the incubation and
hatching of the eggs. We thank Sebastian Estrada, Juan Carlos
Alarcon, and Claudia Ceballos for their support of this study,
and Dean Ripa, Camilo Londoño, and Aaron Gomez A. for
their valuable comments on earlier versions of this manuscript.
This work was funded by grants obtained from Estrategia para
la Sostenibilidad de los Grupos de Investigación (2014–2015),
Universidad de Antioquia.
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