More snakes, because – thanks to Dave Hone – I have some more pictures to use (and, I’ll be honest, at least some of my posts are ‘picture-driven’). We’ve looked previously at the unusual, mostly small, worm-like, burrowing snakes grouped together as the scolecophidians here. In that article, however, I didn’t really emphasise the small size of some scolecophidian species. This photo – taken by Dave in Mexico (is that Dino Frey holding the animal?) – makes the point well.
The smallest scolecophidians are Caribbean leptotyphlopids (aka threadsnakes, wormsnakes or slender blindsnakes) belonging to the genus Leptotyphlops. L. bilineatus (often also called L. bilineata) from Martinique* is said to have a MAXIMUM adult length of 108 mm and was, until recently, listed as the world’s smallest snake (Carwardine 1995). Since then, Hedges (2008) has described the closely related species L. carlae from Barbados [shown below, on some sort of coin], and its total length is given as 104 mm (incidentally, though the holotype of this species was discovered in 2006, two specimens belonging to it have been known since, respectively, 1889 and 1963, it’s just that they were misidentified as belonging to L. bilineatus).
* Specimens from Barbados and St. Lucia once referred to this species actually represent the close relatives L. carlae and L. breuili.
Hedges (2008) noted, however, that sample sizes have an obvious impact on views about maximum size. Of six Leptotyphlops species that have maximum lengths of less than 105 mm (L. dissimilis, L. nicefori, L. pungwensis, L. yemenicus, L. carlae and L. tanae) four are known from single specimens, and at least one of these is a juvenile. In the case of the Socotra Island species L. wilsoni, the two specimens known up until 2004 had total lengths of 100 and 101 mm respectively (meaning, incidentally, that this is the species that should have been in the Guinness Book of Records as ‘world’s smallest snake’, not that Caribbean upstart L. bilineatus). But six additional specimens reported by Rösler & Wranik (2004) increased the maximum length to a gigantic 129 mm. Anyway, the point remains that some threadsnakes are very, very small, and in fact they’re very probably at the extreme lower end of what’s possible in terms of snake body-size. As for the other extreme: well, that’s been in the news lately, as you’ll know.
Regarding the identification of the Mexican species shown in Dave’s photo, I’ll have to pass on that I’m afraid. It might be a leptotyphlopid, but it might also be a typhlopid (or blindsnake).
Refs – -
Carwardine, M. 1995. The Guinness Book of Animal Records. Guinness Publishing, Enfield, Middlesex.
Hedges, S. B. 2008. At the lower size limit in snakes: two new species of threadsnakes (Squamata: Leptotyphlopidae: Leptotyphlops) from the Lesser Antilles. Zootaxa 1841, 1-30.
Rösler, H. & Wranik, W. 2004. A key and annotated checklist to the reptiles of the Socotra Archipelago. Fauna of Saudi Arabia 20, 505-534.