Amphisbaena alba Linnaeus ,Double-headed Worm Lizard - Reptilenesia
Double-headed Worm Lizard Identification
Identification. A legless lizard, with exceptionally small eyes in an ocular scale, body scales smooth, rectangular, and arranged in 220–233 annuli (or rings), another 16−21 annuli on the tail; four upper labials, three lower labials, postoculars can number 1–3; scales around body in a single ring number 70−86. The tail annuli lack a constriction for autonomy. The red-tan to off-white dorsum; the direct contact between the prefrontal and the upper labials; and the higher number of body annuli readily distinguish this species from the other Trinidad Amphisbaena.
Similar species. The Black and White Amphisbaena, A. fuliginosa, has a highly contrasting pattern of black and white; 42−55 scales around the mid-body; three upper tail with constricted base, and 24−28 annuli.
Double-headed Worm Lizard Habitat and Distribution
Distribution. Widespread in South America, ranging from Colombia to Paraguay. It is present on Trinidad, absent from Tobago. It is likely that several different species are currently combined under this name.
Habitat. Forests, savannas, coastal habitats, disturbed environments including cultivated fields.
Biology. Mostly nocturnal but may be found any time of day. This is a fossorial species, but it swims well; one individual swam more than 2.5 km. The diet includes plant material, invertebrates, and small vertebrates. The Double-headed Worm Lizard is often associated with leaf-cutting ant nests; and they are known to follow leaf-cutter ant scent trails. When in ant nests, this lizard feeds on beetles, which are also ant nest commensals. Studies on the life-cycle of a pentastomid parasite found in Amphisbaena alba, report it also depends on ant and beetle commensals for transmission. This suggests A. alba and the leaf-cutters (Atta) have long evolutionary and ecological relationships. Reproduction occurs in the dry season in Brazil; smallest reproductive males 422 mm, smallest reproductive females 457 mm. Clutch size 8–16. The pre-cloacal glands in these lizards secrete molecules as the glands are abraded by soil as they move through tunnels leaving a chemical message for other individuals. When disturbed it partially curls its body and raises its head and tail. The tail is rigid and often contains areas lacking pigment that are most likely scars. The tail is composed of a dense mass of collagen; predators biting the tail cause little damage to lizard. The rest of the external body is also very resistant to damage because of a layer of flexible collagen. Predators include birds and snakes.
Source :
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