fernandina/isabela snake facts
Name: Galapagos/Fernandina/Isabela Snake
Scientific name: Alsophis dorsalis
Length: Up to 120 cm (39 in) sheds skin up to once per year to grow
Number of Species: 28
Endemic Species: 19
Twenty eight species of reptiles have been recorded in Galapagos in recent times. Nineteen of these species are endemic to the archipelago, 11 of which are confined to single islands, and three species have been introduced.
Length: Up to 120 cm (39 in)
Three species of snakes have been recorded in Galapagos (3 terrestrial indigenous residents, two of which are represented by 3 subspecies and the other by 2 subspecies). Endemic species include the Floreana Snake (which includes named subspecies Española Snake and San Cristobal Snake), the Galapagos Snake (which includes named subspecies Fernandina Snake and Isabela Snake), and Slevin's Snake (which includes named subspecies Steindachner's Snake).
Locally fairly common. Two named subspecies occur, mainly in the arid and shore zones: Galapagos Snake dorsalis (Baltra, Rabida, Santa Cruz, Santa Fe and Santiago), Fernandina Snake occidentalis (Fernandina) and Isabela Snake helleri (Isabel a and Tortuga). Feeds by constricting its prey, although slightly venomous.
Virtually impossible to identify unless examined in the hand, identification being confirmed on the basis of the shape, pattern and number of scales on certain parts of the body. As in the other species, predominantly brown with yellow stripes or dark grey with yellow spots on their upper-side forming a zigzag pattern. However, the present species only occurs on islands from which P. biserialis is absent, and although present on the same islands as A. slevini, that species is considerably smaller.