Monday, 9 October 2017

Hypogeophis pti: A new species of Caecilian from Praslin Island, the Seychelles.

Caecilians are limbless burrowing Amphibians found in tropical regions of Asia, Africa and South America. They resemble Earthworms, with circular folds on their skin which make them look segmented and skin covering their eyes (though they can see). Unlike snakes they have greatly reduced or even absent tails with their anus close to or at the tips of their bodies. Caecilians are predatory with a well developed sense of smell. Most Caecilians are found on continents; island dwelling species are very rare in this group. However one island group they have colonised are the tropical Seychelles in the Indian Ocean, where six species have been described to date. Four of these six species, Hypogeophis rostratus, Grandisonia alternans, Grandisonia larvata, and Grandisonia sechellensis, are found across several islands, and appear to be tolerant of a wide range of habitats, while the remaining two, Praslinia cooperi, and Hypogeophis brevis, appear to be restricted to habitats above 350 m, and are found on the two islands of the Seychelles that reach over 400 m, Mahé and Silhouette, with Hypogeophis brevis only ever recorded from Mahé.

In a paper published in the journal Zootaxa on 6 October 2017, Simon Maddock of the Department of Life Sciences at The Natural History Museum, Department of Genetics, Evolution and Environment at University College London, and the School of Biology, Chemistry and Forensic Science at the University of Wolverhampton, Mark Wilkinson, also of the Department of Life Sciences at The Natural History Museum, Ronald Nussbaum of the Museum of Zoology and Department of Ecology and Evolutionary Biology at the University of Michigan, and David Gower, again of the Department of Life Sciences at The Natural History Museum, describe a new species of Caecillian from Praslin Island in the Seychelles.

The new species is named Hypogeophis pti, where 'pti' means small in Seychellois Creole (deriving from the French 'petit'). The species is notably smaller than any other Caecilian from the Seychelles, with less than 70 vertebrae and a maximum recorded length of 116 mm. This species is grey brown in colour, lighter on the underside, with eyes visible as dark spots. The species was found at three locations, around the village of Ma Katrine, and at Fond Peper and Glacis Noir in the Praslin National Park. All specimens were found at altitudes of between 170 and 350 m, in slightly acid silty clay loam or sandy loam soils beneath dense layers of dried leaves.

Live specimen of Hypogeophis pti from Fond Peper in thr Praslin National Park. Maddock et al. (2017).

See also...
Follow Sciency Thoughts on Facebook.