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Abstract

ANILIUS SCYTALE (Red pipesnake): REPRODUCTION. The Red pipesnake inhabits northern South America from southern and eastern Venezuela, Guyana, Suriname, and French Guiana through the Amazon Basin of Colombia, Ecuador, Peru, Bolivia, and Brazil (McDiarmid et al., 1999; Uetz, 1995–2005). It is a viviparous snake with fossorial habits that feeds mainly on elongate fossorial and aquatic vertebrates (Martins & Oliveira 1999), and which escapes from predators either by fleeing (flight category, Seigel & Fitch, 1984) or by using some form of active defense (stand-and-fight; Seigel & Fitch, 1984). Life history data on Ecuadorian populations of this species are scarce or unpublished. The only reproductive data available for Anilius in Ecuador is that reported by Duellman (1978), who states: ‘one female collected in June with small ovarian eggs’. Cunha & Nascimento (1981) reported on seven females from Brasil (520–945 mm total length [TTL]) collected between March and November with ovarian eggs (3–37 eggs/female), two females collected in March and July with eight and ten developing embryos each one; and, seven other females (530–841 mm TTL) collected between February and July with developed embryos (5–8 embryos/female, 184–218 mm TTL). Among these, one female (841 mm TTL) had twelve embryos with a mean TTL of 203.9 ± 2.1 SE mm (194–214 mm TTL, mode = 210 mm), and another (680 mm TTL) had nine embryos with a mean TTL of 196.0 ±2.3 SE mm (185–205 mm TTL, mode = 201 mm). Cunha & Nascimento (1981) stated that A. scytale appeared not to have a defined breeding season, independent from the rainy or dry season, and suggested a gestation period of four to six months. In the Iquitos region (Peru), Dixon & Soini (1986) reported on one female (1184 mm TTL) that gave birth to six young in February 1972; a smaller female that gave birth to four young in January 1966; and a very young specimen taken in early March. Martins & Oliveira (1999) reported on one female (598 mm snout-vent length [SVL], 24 mm tail length [TL]) that gave birth to eight young (154–163 mm TTL) in October; another (898 mm SVL, 29 mm TL, 181 g) that gave birth to 15 young (206–234 mm TTL; combined mass of all 15 young = 52 g; relative clutch mass [RCM] = total offspring mass/female total mass = 0.29); a female (424 mm SVL, 17 mm TL) with seven fully developed embryos (157 – 173 mm TTL) in October; and, a female (898 mm SVL, 29 mm TL) with five developing embryos. On 26th January 1999, a female A. scytale was collected in the Centro Mashient, province of Morona-Santiago, Ecuador. The specimen (FHGO 2355) was maintained in captivity and gave birth to 18 living and 8 stillborn young on 6th February 1999 (FHGO 2356-64, 2373-74, 2378, 2380, 2387-88, 2390-91, 2393-95, 2397, 2403, 2440). The female had a TTL of 1027 mm, and a mass of 155.7 g when collected. The 18 young had a mean TTL of 213.7 ± 2.5 SE mm (190–230 mm TTL, mode 218 mm), and mean mass of 2.8 ± 0.1 SE mm (2.2–3.3 g, mode=2.8 g). Four of the stillborn snakes had a mean TTL of 212.5 ± 3.1 SE mm (206–221 mm TTL) and mean mass of 2.7 ± 0.1 SE mm (2.4–2.9 g). Total litter mass was c. 70 g, RCM = 0.45. The 18 young snakes remained alive for between 53 to 69 days and died of unknown causes. Additional data presented herein indicate that A. scytale litter size varies from 4 to 18 young, with an SVL range of 154–234 mm). Reproductive females had a mean SVL of 718.5 ± 54.2 SE mm (424–1142 mm, n = 15), and relative clutch mass values range from 0.29–0.45. Notwithstanding the small sample size, RCM and SVL range in this species appears to be relatively high compared with other viviparous snakes (e.g. Seigel & Fitch, 1984; Seigel et al., 1986). Also, although a decrease in RCM is often associated with increasing body size in viviparous snakes (Seigel et al., 1986), A. scytale shows a different trend. However, this could be explained by the species’ fossorial habits, supporting Iverson’s hypothesis (in Seigel et al., 1986) regarding the secretiveness of fossorial species permitting higher RCM. Species with burrowing habits are generally less exposed to visual predators and the reproductive cost to females is thus likely to be relatively minor in comparison with species that occur primarily above ground, supporting Seigel et al.’s hypothesis (1986) regarding the ecological explanations for RCM and SVL relationships. Ovarian eggs, developing embryos and young have been reported from January to July, and in October and November, suggesting continual reproduction (Seigel & Ford, 1987) and supporting Martins & Oliveira’s hypothesis (1999).
Natural History Notes
28 Herpetological Bulletin [2005] - Number 92
ANILIUS SCYTALE (Red pipesnake):
REPRODUCTION. The Red pipesnake inhabits
northern South America from southern and eastern
Venezuela, Guyana, Suriname, and French Guiana
through the Amazon Basin of Colombia, Ecuador,
Peru, Bolivia, and Brazil (McDiarmid et al., 1999;
Uetz, 1995–2005). It is a viviparous snake with
fossorial habits that feeds mainly on elongate
fossorial and aquatic vertebrates (Martins &
Oliveira 1999), and which escapes from predators
either by fleeing (flight category, Seigel & Fitch,
1984) or by using some form of active defense
(stand-and-fight; Seigel & Fitch, 1984).
Life history data on Ecuadorian populations of
this species are scarce or unpublished. The only
reproductive data available for Anilius in Ecuador
is that reported by Duellman (1978), who states:
‘one female collected in June with small ovarian
eggs’. Cunha & Nascimento (1981) reported on
seven females from Brasil (520–945 mm total
length [TTL]) collected between March and
November with ovarian eggs (3–37 eggs/female),
two females collected in March and July with
eight and ten developing embryos each one; and,
seven other females (530–841 mm TTL) collected
between February and July with developed
embryos (5–8 embryos/female, 184–218 mm
TTL). Among these, one female (841 mm TTL)
had twelve embryos with a mean TTL of 203.9 ±
2.1 SE mm (194–214 mm TTL, mode = 210 mm),
and another (680 mm TTL) had nine embryos with
a mean TTL of 196.0 ±2.3 SE mm (185–205 mm
TTL, mode = 201 mm). Cunha & Nascimento
(1981) stated that A. scytale appeared not to have
a defined breeding season, independent from the
rainy or dry season, and suggested a gestation
period of four to six months. In the Iquitos region
(Peru), Dixon & Soini (1986) reported on one
female (1184 mm TTL) that gave birth to six
young in February 1972; a smaller female that
gave birth to four young in January 1966; and a
very young specimen taken in early March.
Martins & Oliveira (1999) reported on one female
(598 mm snout-vent length [SVL], 24 mm tail
length [TL]) that gave birth to eight young
(154–163 mm TTL) in October; another (898 mm
SVL, 29 mm TL, 181 g) that gave birth to 15
young (206–234 mm TTL; combined mass of all
15 young = 52 g; relative clutch mass [RCM] =
total offspring mass/female total mass = 0.29); a
female (424 mm SVL, 17 mm TL) with seven
fully developed embryos (157 – 173 mm TTL) in
October; and, a female (898 mm SVL, 29 mm TL)
with five developing embryos.
On 26th January 1999, a female A. scytale was
collected in the Centro Mashient, province of
Morona-Santiago, Ecuador. The specimen (FHGO
2355) was maintained in captivity and gave birth
to 18 living and 8 stillborn young on 6th February
1999 (FHGO 2356-64, 2373-74, 2378, 2380,
2387-88, 2390-91, 2393-95, 2397, 2403, 2440).
The female had a TTL of 1027 mm, and a mass of
155.7 g when collected. The 18 young had a mean
TTL of 213.7 ± 2.5 SE mm (190–230 mm TTL,
mode 218 mm), and mean mass of 2.8 ± 0.1 SE
mm (2.2–3.3 g, mode=2.8 g). Four of the stillborn
snakes had a mean TTL of 212.5 ± 3.1 SE mm
(206–221 mm TTL) and mean mass of 2.7 ± 0.1
SE mm (2.4–2.9 g). Total litter mass was c. 70 g,
RCM = 0.45. The 18 young snakes remained alive
for between 53 to 69 days and died of unknown
causes.
Additional data presented herein indicate that A.
scytale litter size varies from 4 to 18 young, with
an SVL range of 154–234 mm). Reproductive
females had a mean SVL of 718.5 ± 54.2 SE mm
(424–1142 mm, n = 15), and relative clutch mass
values range from 0.29–0.45. Notwithstanding the
small sample size, RCM and SVL range in this
species appears to be relatively high compared
with other viviparous snakes (e.g. Seigel & Fitch,
1984; Seigel et al., 1986). Also, although a
decrease in RCM is often associated with
increasing body size in viviparous snakes (Seigel
et al., 1986), A. scytale shows a different trend.
However, this could be explained by the species’
fossorial habits, supporting Iverson’s hypothesis
(in Seigel et al., 1986) regarding the secretiveness
of fossorial species permitting higher RCM.
Species with burrowing habits are generally less
Natural History Notes
Number 92 - Herpetological Bulletin [2005] 29
exposed to visual predators and the reproductive
cost to females is thus likely to be relatively minor
in comparison with species that occur primarily
above ground, supporting Seigel et al.’s
hypothesis (1986) regarding the ecological
explanations for RCM and SVL relationships.
Ovarian eggs, developing embryos and young
have been reported from January to July, and in
October and November, suggesting continual
reproduction (Seigel & Ford, 1987) and
supporting Martins & Oliveira’s hypothesis
(1999).
ACKNOWLEDGMENTS
I am grateful to Jean-Marc Touzet and Ana María
Velasco for granting access to the specimens
deposited at the FHGO, to Dwain Holmes for
donating the pregnant specimen of Anilius scytale.
To Anita Peñaherrera, Gabriel Touzet, Margarita
Brandt, Andrés León, and Tomi Sugahara for
laboratory assistance. To Roy McDiarmid and to
the Savanna River Ecology Laboratory for sharing
literature. My gratitude to Maria Elena Heredia
and Laura Heredia for financial and moral support.
Universidad San Francisco de Quito provided
institutional support.
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Dixon, J. R. & Soini, P. (1986). The Reptiles of the
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Duellman, W. E. (1978). The biology of an
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Seigel, R. A. & Fitch, H. S. (1984). Ecological
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Seigel, R.A. & Ford, N.B. (1987). Reproductive
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& Novak, S.S. (Eds.). New York: Macmillan
Publ. Co.
Seigel, R. A. Fitch, H. S. & Ford, N. B. (1986).
Variation in relative clutch mass in snakes
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Uetz, P. (1995-2005). The EMBL Reptile
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DIEGO F. CISNEROS-HEREDIA
College of Biological and Environmental
Sciences, Universidad San Francisco de Quito,
Ave. Interoceánica y calle Diego de Robles,
Campus Cumbayá, Edif. Maxwell. Casilla Postal
17-12-841, Quito, Ecuador. E-mail:
diegofrancisco_cisneros@yahoo.com)
... Taxa Color image of this figure appears in the color plate section at the end of the book. the wet or dry season (Martins and Oliveira 1999;Cisneros-Heredia 2005;Maschio et al. 2007). Molecular divergence dating indicates that this family likely originated at the K/T boundary (Burbrink and Pyron 2008). ...
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Reproductive ecology
  • R A Seigel
  • N B Ford
Seigel, R.A. & Ford, N.B. (1987). Reproductive ecology. In Snakes: Ecology and Evolutionary Biology, pp. 210-252. Siegel, R.A. Collins, J.T. & Novak, S.S. (Eds.). New York: Macmillan Publ. Co.
  • O R Cunha
  • Da
  • F Nascimento
Cunha, O. R. da, & Nascimento, F. P. do. (1981).
The Reptiles of the Upper Amazon Basin
  • J R Dixon
  • P Soini
Dixon, J. R. & Soini, P. (1986). The Reptiles of the Upper Amazon Basin, Iquitos Region, Peru. Milwaukee: Milwaukee Pub. Mus. Press. 154 pp.
The EMBL Reptile Database. Online. EMBL Heidelberg: <http://www.reptile-database.org> [Accessed on
  • P Uetz
Uetz, P. (1995-2005). The EMBL Reptile Database. Online. EMBL Heidelberg: <http://www.reptile-database.org> [Accessed on December 2004].