Herpetology Notes, volume 8: 629-631 (2015) (published online on 20 December 2015)

Intraclutch characteristics of the Wagler’s viper, Tropidolaemus wagleri (Serpentes: Viperidae), in Singapore

Ryan J. R. McCleary1,2,*, Mary-Ruth Low1 and David P. Bickford1

As currently recognized (Vogel et al., 2007), having a dark background with light yellow, white, Tropidolaemus wagleri (Wagler’s Pit Viper, Wagler’s and/or blue patches along the body. Males, on the other Palm Viper, Wagler’s Keeled Green Pit Viper, Temple hand, are bright green with small bars of reddish-brown Viper, or Temple Pitviper) is found throughout Southeast and white along the entire dorsal aspect (Grismer, Asia, from southern Thailand to peninsular Malaysia and 2011). Females are also much larger than males in Singapore; to the Indonesian islands of Sumatra, Nias, both length and mass. These differences make the the Mentawai Archipelago, Pulau Bangka, the Riau species an ideal candidate for studies of sexual selection Archipelago, and Pulau Natuna; and with a seemingly and reproduction, but very little has been reported isolated population in southern Vietnam (Orlov et al., concerning reproduction in the wild. Two reports of 2003). Although it can be found in habitats ranging clutch sizes have been previously published as “about from mangroves to swamps to lowland forests, in 15” (David and Vogel, 1996), 25 (Hagen, 1890), and Singapore it is one of the more common snakes (pers. 41 (from an adult in captivity; Lim, 1990), and Das obs.) in the undisturbed areas of the Central Catchment (2010) indicated average lengths of neonates to be 150 (CCNR) and Bukit Timah Nature Reserves (BTNR) and mm, although no specific data are given. Therefore, Pulau Tekong, the only locales in Singapore that still any information pertaining to reproduction in terms contain primary and old secondary forest patches. The of numbers, size at birth, and reproductive effort are species is highly arboreal (David and Vogel, 1996), and important for understanding this species. individuals can often be found a meter or more above On 15 April 2014 at approximately 2230 h, we the ground in branch tangles of shrubs and trees. Like collected a female T. wagleri in the CCNR, Singapore some other viper species, they appear to have strong site (01.36864°N 103.78176°E; datum: WGS 84) fidelity, often remaining in the same vicinity for a week approximately 1.5 m above the ground in a thicket of or longer. They are also ambush predators (pers. obs.). branches (Fig. 1A). Although it was not readily apparent Although not considered of medical importance due that the animal was gravid (even with palpation), on 15 to low incidences of human envenomation (David and May 2014, it produced thirteen offspring (12 alive, 1 Vogel, 1996), the species is venomous, and its venom stillborn; Fig. 1B) and two undeveloped ova while in contains toxic components (Molles and Taylor, 2002; captivity. All offspring were resting on the tops of Chang et al., 2008). branches within the enclosure, displaying immediate Tropidolaemus wagleri is atypical for a viper as it arboreal behavior post-partum. As has been previously exhibits strong adult sexual dimorphism, with females reported (Vogel et al., 2007), all offspring had the same phenotype as adult males. They also all had white tail tips (Fig. 1C), indicating potential for caudal luring behavior (Heatwole and Davison, 1976). The combined post-partum neonate and ova mass was 63.12 g, which is 29.2% of the mass of the mother post-partum or 22.6% 1 National University of Singapore, Department of Biological of the combined mass of adult and offspring (see Table Sciences, 14 Science Drive 4, Singapore 117543 2 Current address: Utah State University, Department of 1). The adult female and all 12 living offspring were Biology, 5305 Old Main Hill, Logan, UT 84322-5305 released in the wild at the point of the adult’s capture. * Corresponding author e-mail: [email protected] To our knowledge, this is the first description of relative 630 Ryan J. R. McCleary et al.

Figure 1. A) Tropidolaemus wagleri adult mother at site of capture in the Central Catchment Nature Reserve in Singapore, B) neonates, and C) neonates showing white tail tips indicative of caudal luring behavior (circled in photo). Photographs by R. J. R. McCleary.

Table 1. Measurements of adult, neonates, and unfertilised eggs of Tropidolaemus wagleri, post-partum.

4 Animal ID Mass (g) SVL (mm) Tail length (mm) Adult mother 216.26 693 127 Neonate 1 5.2138 176 41 Neonate 2 4.7256 177 29 Neonate 3 4.7013 172 34 Neonate 4 4.3484 188 29 Neonate 5 4.5305 180 39 Neonate 6 4.7290 176 36 Neonate 7 4.7983 178 39 Neonate 8 3.8137 172 36 Neonate 9 4.7479 169 36 Neonate 10 4.8741 184 38 Neonate 11 4.8327 182 40 Neonate 12 4.7438 182 39 Neonate 13 (stillborn) 3.7894 176 42 Neonate average (SD) 4.6037 (0.406) 177.8 (5.3) 36.8 (4) Undeveloped ova 1 2.0504 Undeveloped ova 2 1.2231 Intraclutch characteristics of Tropidolaemus wagleri in Singapore 631 clutch mass and intra-clutch variation from wild-caught T. wagleri. It also expands the lower end of clutch size range for fully developed offspring and adds to the limited data currently available on wild reproduction in this common species. This work was conducted with permission of the National University of Singapore Institutional Animal Care and Use Committee (B01/ 11(A1)13) and National Parks Board of Singapore (NPRP10-095-2a).

References

Chang, C.-H., Chung, C.-H., Kuo, H.-L., Hsu, C.-C., Huang, T.-F. (2008): The highly specific platelet glycoprotein (GP) VI agonist trowaglerix impaired collagen-induced platelet aggregation ex vivo through matrix metalloproteinase-dependent GPVI shedding. Journal of Thrombosis and Haemostasis 6: 669-676. Das, I. (2010): Reptiles of South-east Asia. London, New Holland Publ. Ltd. David, P., Vogel, G. (1996): The Snakes of Sumatra. Frankfurt am Main, Edition Chaimara. Grismer, L.L. (2011): Amphibians and Reptiles of the Seribuat Archipelago. Frankfurt am Main, Edition Chaimara. Hagen, B. (1890): Die Pflanzen- und Thierwelt von Deli auf der Ostküste Sumatras : naturwissenschaftliche Skizzen und Beitrage. Leiden, E.J. Brill. Heatwole, H., Davison, E. (1976): A review of caudal luring in snakes with notes on its occurrence in the Saharan sand viper, Cerastes vipera. Herpetologica 32: 332-336. Lim, B.L. (1990): Venomous land snakes of Malaysia. In: Snakes of Medical Importance (Asia-Pacific Region), p. 387-417. Gopalakrishnakone, P., Chou, L.M., eds., Singapore, Venom and Toxin Research Group National University of Singapore and International Society on Toxinology (Asia-Pacific Section). Molles, B.E., Taylor, P. (2002): Structure and function of the waglerins, peptide toxins from the venom of Wagler’s pit viper, Tropidolaemus wagleri. Toxin Reviews 21: 273-292. Orlov, N.L., Ryabov, S.A., Sang, N.V., Truong, N.Q. (2003): New records and data on the poorly known snakes of Vietnam. Russian Journal of Herpetology 10: 217-240. Vogel, G., David, P., Lutz, M., van Rooijen, J., Vidal, N. (2007): Revision of the Tropidolaemus wagleri-complex (Serpentes: Viperidae: Crotalinae). I. Definition of included taxa and redescription of Tropidolaemus wagleri (Boie, 1827). Zootaxa 1644: 1-40.

Accepted by Anamarija Zagar