Herpetology Notes, volume 14: 53-54 (2021) (published online on 09 January 2021)

Observation on clutch size and embryo colour of Psammodynastes pulverulentus (Boie, 1827) in Taiwan (: Colubridae)

Chun-Kai Yang

Psammodynastes pulverulentus (Boie, 1827), the The clutch size of this road-killed female falls within this common mock viper, is widely distributed in Nepal, range. This study supports observations by Dieckmann India, Southeast Asia, Philippines, China, and Taiwan et al. (2013) that the colour of juvenile P. pulverulentus (Miller and Zug, 2016). In Taiwan, this common varies and is not always the same as that of the mother. species is widespread in lowland cultivated habitats and secondary forests (Tu, 2004). Here, I report on a road- Acknowledgements. I thank my undergraduate colleague Tang killed female carrying embryos in her body. Hsin for collecting the specimen during a road-kill survey. At 10:14 h on 2 July 2018, a road-killed was collected by a colleague at Fenglin Township, Hualien References County, Taiwan (23.7898°N, 121.3711°E). The snake Boback, S.M., Dichter, E.K., Mistry, H.L. (2012): A developmental was identified as a female P. pulverulentus, with staging series for the African house snake, Boaedon embryos in her oviduct. Because she had been run over (Lamprophis) fuliginosus. Zoology 115: 38–46. by a vehicle, some embryos were partially exposed Dieckmann, S., Norval, G., Mao, J. (2013): Notes on four from three parts of her oviduct. Heads of all embryos Psammodynastes pulverulentus papenfussi Zhao, 1995 (Squamata: Colubridae) litters from eastern Taiwan. remained inside her body (Fig. 1). With forceps, I Herpetolology Notes 6: 497–499. carefully removed the embryos from the female. Miller, A.H., Zug, G.R. (2016): Morphology and biology of the The eight embryos had developed to Stage 10 (Fig. Asian Common Mockviper, Psammodynastes pulverulentus 2A): scales and teeth were well developed (Boback (Boie, 1827) (Serpentes: ): a focus on Burmese et al., 2012). Although some embryos were partially populations. Proceedings of the Biological Society of damaged or dismembered, I measured the length of Washington 129: 173–194. all individuals. The female was 418 mm in snout-vent Pope, C.H. (1929): Notes on from Fukien and other length, the eight embryos measured 170–210 mm in Chinese provinces. Bulletin of the American Museum of Natural History 58: 335–487. total length (Table 1). In India, neonates are 150–180 Pope, C.H. (1935): The reptiles of China: turtles, crocodilians, mm in total length (Whitaker et al., 2004). These road- , lizards. Bulletin of the American Museum of Natural killed embryos were therefore at the higher end of the History 10: 1–604. length spectrum for neonates of P. pulverulentus. Based on criteria defined by Dieckmann et al. (2013), four embryos were classified as the light colour morph and the others as the dark colour morph (Fig. 2B). Their mother was classified as the light colour morph. The colour morph ratio in this clutch was therefore 1:1 (Dieckmann et al., 2013). Dieckmann et al. (2013) and Pope (1929, 1935) reported a clutch size of 3–10 eggs in P. pulverulentus.

Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan. 410054001@ gms.ndhu.edu.tw Figure 1. Body of a road-killed female Psammodynastes pulverulentus found in Hualien County, Taiwan. Some embryos © 2020 by Herpetology Notes. Open Access by CC BY-NC-ND 4.0. had been forced out of her body. 54 Chun-Kai Yang

Tu, M.-C. (2004): Big Surprise of Snakes. Taipei, Yuan-Liou Co. Whitaker, R., Captain, A., Villa, R. (2004): Snakes of India – the [In Chinese] Field Guide. Chennai, India, Draco Books.

Table 1. Total length and body colour morph of each Psammodynastes pulverulentus embryo removed from a road killed female collected in Hualien County, Taiwan.

Embryo No. Colour morph Total length (mm) Damage status 1 light 206 Fractured in two places 2 light 188 Dismembered into two parts; one fracture 3 light 180 Dismembered into two parts 4 light 204 Dismembered into three parts 5 dark 198 Body intact 6 dark 179 Dismembered into two parts 7 dark 217 One fracture 8 dark 207 Body intact

Figure 2. (A) Eight embryos removed from a road-killed female Psammodynastes pulverulentus from Hualien County, Taiwan. All embryos were fully developed, indicating that this species is viviparous. (B) Colouration variation in siblings from the same litter. The upper individual represents the dark colour morph, whereas the lower individual represents the light colour morph.

Accepted by Colin Strine