The attractive spiders-web pattern that adorns the shell of this species is both the reason for its name and, owing to the exotic pet trade, one of the main factors behind its precarious situation (1) (3) (5). The spider tortoise is a small reptile, with an oblong shell that is highly curved and widens towards the rear. The shell is decorated with five to eight yellow lines radiating out from a yellow centre, against a dark brown or black background. The shell on the underside of the tortoise, known as the plastron, is yellow. The head is dark and speckled with several yellow spots, and the legs and tail are brown. The tail of the male is longer and thicker than that of the female, and has a harder tip (6).
Three geographically separated subspecies of the spider tortoise are currently recognised (Pyxis arachnoides arachnoides, P. a. oblonga, and P. a. brygooi), with the presence, or varying mobility, of a plastron hinge providing the bases for this determination (4) (7). Pyxis arachnoides arachnoides has a semi hinged plastron, allowing the tortoise to retract its head and front legs and close itself in its protective shell, hence the scientific name Pyxis, which means box. Pyxis arachnoides brygooi completely lacks a hinge on the plastron, while Pyxis arachnoides oblonga has the most mobile plastron hinge allowing complete closure and quite often has black marks on the plastron (7).
- Pyxide Arachnoide, Tortue-araignée.
- Tortuga Araña.
- Average shell length: 11.1 (2)