TEMPERATURE RESPONSES IN THE INDIAN SAND LIZARD, OPHIOMORUS STREETI ANDERSON AND LEVITON

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There are many physical factors in ecology influencing the desert lizards, but the role of temperature is of great importance because the environmental temperature controls the degree of their activities to a large extent and imposes limitations on their movements and distribution. Ophiomorus streeti is a desert dweller fossorial by habit, but, like other terrestrial lizards, it does not hibernate but remains buried in the loose sand in a state of torpor during winter and emerges occasionally to search for food, restricting thereby its activity within a tolerable temperature range. Though much work has been done in regard to temperature responses in reptiles-COWELS (1940 & 1941), COWELS & BOGERT (1944), BOWERS & SMITH (1947), NEIL (1948), BOGERT (1949) & FITCH (1954,1955,1956) etc., thermoregulation in burrowing forms, like Ophiomorus, is still to be studied. Therefore, this paper contributes to our knowledge on the temperature responses in this lizard. The experiments were conducted in 1968 at Jodhpur in Western Rajasthan (India), an are a in the southern part of this province insufficiently watered and unproductive but abounding in sand dunes was chosen for study. Experiments were conducted both, in nature and in captivity. The mean maximum temperature in Jodhpur is 25.9℃. and the mean minimum temperature is 10.4℃. during winter and 37.9℃. and 15.8℃. during post monsoon. The average rainfall is 366mm. Experimentally, the optimum temperature for the lizard was 29.0℃±1.5℃ and the lethal 44.0〜47.8℃.