Herpetology Notes, volume 8: 479-481 (2015) (published online on 03 October 2015)

A fish-scaled gecko (Geckolepis sp.) escapes predation by a velvet gecko (Blaesodactylus sp.) through skin shedding

Charlie Gardner1,*, Louise Jasper2

Many reptiles have evolved the ability to shed part night walk as tourists within the Bekaraoka forest block of their body in response to predator attack. The most of Loky-Manambato new protected area (13°08’38’’ widespread form is caudal autotomy, the shedding of S, 49°42’25’’ E), near the town of Daraina in extreme all or part of the tail, which occurs in many lizards and north-east Madagascar. At 19:25 we were alerted by amphisbaenians as well as some snakes and the tuataras movement on a tree trunk about 3 m away, and in our (Arnold, 1984; Bateman and Fleming, 2009): breakable torchlight observed a large Blaesodactylus that had tails allow potential prey animals to avoid predation captured a smaller gecko in its jaws and was struggling by i) providing a distraction away from the animal’s with it (Fig. 1). The animals immediately disappeared vulnerable head and torso, and ii) allowing animals that behind the tree but reappeared after a few seconds, at have been grasped by the tail to break free and escape. which point there were several violent, jerky movements Members of the gecko genus Geckolepis Grandidier, accompanied by the slap of the prey animal against the 1867 have evolved an even more extreme adaptation, tree trunk; however, we cannot say whether these were and are able to autotomise all or most of their skin when attempts by the predator to subdue its prey, or the efforts grasped; their skin is covered with large, overlapping of the prey to escape. After about 30 seconds following scales which easily fall off, and give rise to their English our initial observation, the prey animal suddenly slipped name of fish-scaled geckos (Schubert and Christophers, from the mouth of the Blaesodactylus and we both had 1985; Schubert et al, 1990; Bauer, 2003). While clearly a clear glimpse of the naked, pink torso of the gecko as an anti-predation strategy, little is known about the it flew through the air. On landing it crawled inside a predators against which it has evolved: since the genus rotten log on the ground and we were unable to relocate is arboreal and nocturnal, it has been hypothesised that it. nocturnal snakes (e.g. Madagascarophis, Stenophis) We identified the prey item as a Geckolepis on the may be likely predators (Glaw and Vences, 2007), basis of its naked torso as it escaped, an impression although the consumption of Geckolepis by diurnal birds confirmed by Fig. 1b in which the large scales are has also been observed (Gardner and Jasper, 2014). clearly visible. In addition, a scale can be seen on the Here we present an observation of a Geckolepis upper labials of the Blaesodactylus following the prey’s predation attempt by a velvet gecko (Blaesodactylus escape (Fig. 2b). However, we are unable to identify sp.), in which the prey animal, having been captured, the animal to species level because the taxonomy of the was able to avoid being consumed by shedding its skin genus is extremely complex (Köhler et al., 2009) and and escaping. On 27.11.2014 we were conducting a it contains a number of undescribed, cryptic lineages (Lemme et al., 2013). Likewise, we can only speculate on the specific identity of the Blaesodactylus specimen observed in the absence of a voucher specimen (Fig. 2). Of the four species currently recognised (Bauer et al., 2011), both B. sakalava and B. antongilensis 1 Durrell Institute of Conservation and Ecology, School of have been recorded from Loky-Manambato (in dry Anthropology and Conservation, University of Kent, Canterbury, Kent, CT2 7NR, UK; and humid forests, respectively), although only the 2 Cité Sisal 13, Toliara 601, Madagascar. former has been recorded in the Bekaraoka forest block * Corresponding author e-mail:������������������� cjamgardner�@�����������yahoo.co.uk (Rakotondravony, 2007). However, the animal we 480 Charlie Gardner & Louise Jasper

Figure 1. a) Blaesodactylus sp. predating a Geckolepis sp. in the Bekaraoka forest, Loky-Manambato protected area, b) magnification showing the distinctive Geckolepis scale pattern of the prey animal. Photo L. Jasper.

Figure 2. a) Blaesodactylus immediately following the escape of its Geckolepis prey, at Bekaraoka forest, Loky-Manambato protected area, b) magnification showing a Geckolepis scale remaining on the predator’s labials. Photo L. Jasper. A fish-scaled gecko escapes predation by a velvet gecko through skin shedding 481 photographed most closely resembles B. boivini on the Köhler, G., Diethert, H.-H., Nussbaum, R.A., Raqxworthy, C.J. basis of external morphology (F. Glaw, pers. comm.) (2009): A revision of the fish scale geckos, genus Geckolepis (Figs. 1 and 2). Little is known about the foraging Grandidier (Squamata, Gekkonidae) from Madagascar. Herpetologica 65: 419-435. mode or prey of any Blaesodactylus species, though Lemme, I., Erbacher, M., Kaffenberger, N., Vences, M., Köhler, B. ambonihazo has been classified as a sit-and-wait G. (2013): Molecules and morphology suggest cryptic species predator (Ikeuchi and Mori, 2014). diversity and an overall complex taxonomy of fish scale geckos, genus Geckolepis. Organisms,���������������������������������� Diversity and Evolution 13: 87- Acknowledgements. We thank Frank Glaw for providing 95. additional literature and comments that improved an earlier Rakotondravony, H.A. (2007): Conséquences de la variation version of the manuscript. des superficies forestières sur les communautés de reptiles et d’amphibiens dans la région Loky-Manambato, extrême nord- References est de Madagascar. Revue d’Ecologie, la Terre et la Vie 62: 209-227. Arnold, E.N. (1984): Evolutionary aspects of tail shedding in lizards Schubert, C., Christophers, E. (1985): “Dermolytische and their relatives. Journal of Natural History 18: 127-169. schreckhäutung” – ein besonderes autotomieverhalten von Bateman, P.W., Fleming, P.A. (2009): To cut a long tail short: a Geckolepis typica (Reptilia, Geckonidae). ������������Zoologischer review of lizard caudal autotomy studies carried out over the last Anzeiger 214: 129-141. 20 years. Journal of Zoology 277: 1-14. Schubert, C., Steffen, T., Christophers, E. (1990): Weitere Bauer, A.M. (2003): Gekkonidae, geckos. In The Natural History beobachtungen zur “dermolytischen schreckhäutung” bei of Madagascar, p. 973-977. Goodman, S.M., Benstead, J.P., Geckolepis typica (Reptilia, Gekkonidae). Zoologischer Eds., Chicago, The University of Chicago Press. Anzeiger 224: 175-192. Bauer, A.M., Glaw, F., Gehring, P.-S., Vences, M. (2011): New species of Blaesodactylus (Squamata: Gekkonidae) from Ankarafantsika National Park in north-western Madagascar. Zootaxa 2942: 57-68. Gardner, C.J., Jasper, L.D. (2014): A record of vertebrate carnivory by the crested drongo (Dicrurus forficatus). Malagasy Nature 8: 105-106. Glaw, F., Vences, M. (2007): A Field Guide to the Amphibians and Reptiles of Madagascar, 3rd Edition. Köln, Vences and Glaw Verlags GbR. Ikeuchi, I., Mori, A. (2014): Natural history of a Madagascan gecko Blaesodactylus ambonihazo in a dry deciduous forest. Current Herpetology 33: 161-170.

Accepted by Miguel Vences