GERLACH, J. (2009)

Aldabrachelys arnoldii (Bour 1982) – Arnold's Giant Tortoise.

Conservation Biology of Freshwater Turtles and Tortoises. 028.1. A Compilatory Project of the IUCN/SSC Freshwater Turtle and Tortoise Specialist Group. Chelonian Research Monographs No. 5 (ISSN 1088-7105).

Summary:

Arnold’s  giant  tortoise, Aldabrachelys  arnoldi (=  Dipsochelys  arnoldi)   (Family Testudinidae), from the granitic Seychelles, is a controversial species possibly distinct from the Aldabra giant tortoise, A. gigantea  (= D. dussumieri  of some authors). The species is a morphologically distinctive morphotype, but has so far not been genetically distinguishable from the Aldabra tortoise,  and  is  considered  synonymous  with  that  species  by  many  researchers.  Captive  reared juveniles suggest that there may be a genetic basis for the morphotype and more detailed genetic work is needed to elucidate these relationships. The species is the only living saddle-backed tortoise in the Seychelles islands. It was apparently extirpated from the wild in the 1800s and believed to be extinct until recently purportedly rediscovered in captivity. The current population of this morphotype is 23 adults, including 18 captive adult males on Mahé Island, 5 adults recently introduced to Silhouette Island, and one free-ranging female on Cousine Island. Successful captive breeding has produced 138 juveniles to date.