Seychelles reptiles & amphibians

The Seychelles islands support a remarkable range of amphibians and reptiles found no-where else in the world. The data I collected is published in scientific papers and contributed to the Global Amphibian Assessment and the Global Reptile Assessment.

Amphibians

8 species of caecilian are known from the islands. These legless burrowing amphibians are very poorly known.

Grandisonia alternans, Grandisonia brevis, Grandisonia larvata, Grandisonia sechellensis, Hypogeophis rostratus, Praslinia cooperi

6 species of frogs have been identified in Seychelles. These comprise the Mascarene frog Ptychadena mascariensis (probably introduced), the Seychelles tree frog (Tachycnemis seychellensis) and four species of the endemic frog family Sooglossidae. I carried out research into the status of all these species, with a particular interest in Sooglossidae, leading to the discovery of a new species Seychellophryne pipilodryas, in addition to Seychellophryne gardineri, Sooglossus sechellensis and Sooglossus (Nesomantis) thomasseti. We collaborated on research into their acoustic biology, reproduction and evolution, and developed monitoring methods for these elusive frogs, results of this were published in 2007.

Reptiles

The islands used to have an exceptional chelonian fauna of 9 species: sea turtles, Seychelles terrapins and Seychelles giant tortoises (including 5 endemic species and 2 endemic subspecies) in a small geographical area. These were two of the seven sea turtle species (green turtle Chelonia mydas and hawksbill turtle Eretmochelys imbricata), three terrapins (Pelusios subniger parietalis, Pelusios castanoides intergularis and the extinct Pelusios seychellensis) and four tortoises (Aldabra giant tortoise, Seychelles giant tortoise, Arnold's tortoise and the extinct Daudin's tortoise).

The 20 species of lizard include the geckos Phelsuma sundbergi, Phelsuma astriata, Phelsuma laticauda, Phelsuma abbotti, Urocotyledon inexpectata, Ailuronyx seychellensis, Ailuronyx trachygaster, Ailuronyx tachyscopaeus, Hemidactylus mercatorius, Hemidactylus frenatus, Hemidactylus brooki, Gehyra mutilata and Lepidodactylus lugubris, the skinks Trachylepis sechellensis, Trachylepis wrightii, Pamelascincus gardineri, Janetascincus braueri, Janetascincus veseyfitzgeraldi and Cryptoblepharus boutonii, and the girdled lizard Zonosaurus madagascariensis insulans.  

One of the most interesting of the Seychelles geckos is Ailuronxy trachygaster, the giant bronze gecko. This has been an enigma since 1851 when it was described from Madagascar. Despite much interest in this large (30cm), heavily built gecko no-one has been able to find living animals anywhere on Madagascar. It is related to two smaller species found in the Seychelles islands and for many years it was suspected that the 1851 specimen had originally come from Seychelles and had been incorrectly labelled. In the 1990s exceptionally large geckos were spotted in the Vallee de Mai on Praslin island and after much careful research I managed to identify these as the long-lost giant bronze gecko. With this very restricted range it is Vulnerable to any further habitat deterioration or range contraction.

There are two species of chameleon Archaius species. Although found on three islands their populations are at low density and just 2,000 individuals are thought to exist. As with most island species they are threatened by invasive plants which degrade the primary forests. These continue to spread at an ever increasing pace on many islands, accordingly the chameleons are considered to be Endangered. These species do not bury their eggs in soil like all other chameleons, but lay them in the axils of pineapple plants, an introduced species. Where they bred before the pineapples invaded remains a mystery. More and more island species are being forced into depending on introduced species as their natural associations are lost.

Three species of land snake are resident breeders: the introduced flowerpot snake Rhamphotyphlops braminus, and the two endemic species of house snake Lycodon geometricus and wolf snake Lycognathophis sechellensis. The sea-snake Pelamis platurus has been observed in Seychelles waters but is not resident. The status of the terrestrial species is being monitored, the endemic species are considered to be Endangered.

Tachycnemis seychellensis

Seychelles biodiversity

Phelsuma journal

Contact

Justin Gerlach by e-mail