Herpetological Review 47(1), 2016
SQUAMATA — SNAKES
EUNECTES MURINUS (Green Anaconda). REPRODUCTION /
FACULTATIVE PARTHENOGENESIS. Obligate parthenogenesis
is well documented in at least 25 species of lizards, but only a
single snake species, Indotyphlops (formerly Ramphotyphlops)
braminus (Vrijenhoek et al. 1989. In Dawley and Bogert [eds.],
Evolution and Ecology of Unisexual Vertebrates, pp. 19–23
Bulletin 466, New York State Museum, Albany, New York).
Occasional cases of facultative parthenogenesis have also now
been documented in an increasing number of otherwise sexual
snake species, including Python bivittatus (Groot et al. 2003.
Heredity 90:130–135); Boa constrictor (Booth et al. 2011. Biol.
Lett. 7:253–256); Epicrates cenchria (Kinney et al. 2013. 2–13.
Zoo Biol. 32:172–176); E. maurus (Booth et al. 2011. J. Hered.
102:759–763); Acrochordus arafurae (Magnusson 1979. Copeia
1979:744–745; Dubach et al. 1997. Herpetol. Nat. Hist. 5:11–
18); Thamnophis couchii (Germano and Smith 2010. Southwest.
Nat. 55:280–282); T. elegans vagrans and T. marcianus (Schuett
et al. 1997. Herpetol. Nat. Hist. 5:1–10); Agkistrodon contortrix
(Booth and Schuett 2011. Biol. J. Linn. Soc. 104:934–942); Crotalus
durrisus unicolor and C. horridus (Schuett et al., op. cit.). We here
report the first documented case of facultative parthenogenesis
in Eunectes murinus.
On 11 August 2014, a female E. murinus (SVL = 2462; total
length = 2832 mm), held in the collection at Mark O’Shea’s
Reptile World, Discovery Trail, West Midland Safari Park (WMSP),
Bewdley, Worcestershire, United Kingdom, gave birth to three
live and five dead neonates, all confirmed as females (SVL = 600–
685 mm; total length = 715–795 mm). The female has been in
the collection since 27 March 2009 (5 years, 4.5 months) during
which time it has been maintained solely in the company of a
single larger (4.0 m+) female. Prior to its arrival at WMSP, as an
immature subadult, the female was maintained in a private
collection, also in isolation from any male, thereby ruling out the
possibility of long-term sperm-storage being responsible for the
The small size of the litter, the high mortality, and its all-
female composition, are all compatible with other cases of boid
parthenogenesis (Booth et al. 2011. J. Hered. 102:759–763;
Kinney et al., op. cit.). Tissue and blood samples were taken
from all live and dead neonates, and the adult female, as part of
regular veterinary screening requirements, and surplus samples
were shipped to Warren Booth, University of Tulsa, Oklahoma,
USA. The dead neonates were accessioned into the Natural
History Museum, London (NHMUK 2013.486–490, field nos.
MOS 3500–04). The three live neonates were maintained in the
WMSP collection, with the subsequent death of the weakest
on 7 January 2015. Post-mortem gross and histopathological
examination of this individual identified bacterial and fungal
pathogens and reduced body condition; the carcass was not
retained. At the time of writing, almost 15 months post-birth, the
remaining two neonates are feeding well and thriving.
MARK O’SHEA (e-mail: email@example.com), STEVE SLATER, RE-
BECCA SCOTT, Discovery Trail, West Midland Safari Park, Bewdley, Worces-
tershire, DY12 ILF, United Kingdom; SARAH SMITH, Veterinary, WMSP,
Bewdley, Worcestershire, DY12 ILF, United Kingdom; KATIE McDONALD,
Research, WMSP, Bewdley, Worcestershire, DY12 ILF, United Kingdom; BOB
LAWRENCE, Development, WMSP, Bewdley, Worcestershire, DY12 ILF,
United Kingdom; MARIE KUBIAK, Manor Vets, 373 Hagley Road, Birming-
ham, West Midlands, B17 8DL, United Kingdom.