Scientists have discovered a new species of caecilian – a worm-like amphibian – on an island in the Seychelles.
Dr Simon Maddock, a Lecturer in Conservation Genetics at the University of Wolverhampton, was part of a team who spent more than 300 person hours of digging before they uncovered the new amphibian species. The new species has been formally published today in the journal Zootaxa, an international journal for zoological taxonomists.
The work in the Seychelles was completed alongside government and non-government organisations, and with colleagues from the Natural History Museum, London and University of Michigan, USA. The new species is restricted to the island of Praslin, one of the northern granitic islands of the Seychelles, which is drier and hotter than many of the lusher islands to the south. The team has named the new species the petite Praslin caecilian (Hypogeophis pti), due to its small size. The little known legless caecilians (order Gymnophiona) are the third group of amphibians with the frogs and toads (order Anura), and the salamanders and newts (order Caudata) forming the other two.
Dr Maddock said: “Caecilians are common in the Seychelles but they are not widely known to people because they live underground.
“This new species has not been encountered on other islands during hundreds of hours of dedicated caecilian surveys between 1976 and 2017. As soon as I saw it I knew it was a new species; it is a very exciting discovery and I was delighted to be able to formally describe it and present it to the world.”
Seven species of caecilians are native to the Seychelles. They completely lack limbs, making the smaller species resemble worms, while the larger species can reach lengths > 40cm; some species can grow to > 1.5m in other parts of the world. The petite Praslin caecilian could represent the smallest species in the world, with a maximum recorded length of just 120mm.
The new species differs most obviously from other caecilian species in the Seychelles by having an elongated snout and the position of tentacle (a unique sensory organ in caecilians) being closer to the eye than the nostril, in the most similar species. They also have the fewest vertebrae of any caecilian in the world; vertebrae are inversely associated with length of animals, supporting this petite Praslin caecilian as probably the smallest caecilian species.
The petite Praslin caecilian has a small geographic range, making it threatened with extinction. Furthermore, the region in which it occupies has seen two independent mortality events in caecilians, posing questions about its survival. The caecilian team will now be continuing their investigations and gathering more information and data to aid the survival of the species.
Notes to Editors
Praslin is one of two islands that are home to a palm that produces the largest nut in the world (weighing up to 30kg), the coco de mer.