 |
|
Squamata, Serpentes, Acrochordidae - File Snakes |
| File Snakes are the remnants of an ancient snake lineage that was related to the ancestor of modern snakes. They form the sister group to the caenophidian (advanced) snakes. Unique among snakes, they have scales that contain sensory organs and tubercles on the skin between the scales. The scales also hold sensory bristles and their rough texture aids the snake is holding slippery prey in the folds of its body. Three currently recognized species are placed in the genus Acrochordus. File snakes range from India eastward to Southeast Asia, Australia, New Guinea, and the Solomon Islands. A single fossil species is known from the upper Miocene of Pakistan. All three species are highly aquatic. Two (A. arafurae and A. javanicus) are freshwater although A. javanicus is said to use brackish and saltwater, the third (A. granulatus) is marine and estuarine. All eat fish, but the little granular file snake (A. granulatus) also feeds on crustaceans, and apparently these snakes feed infrequently. All three species are viviparous with A. arafurae giving birth to litters of up to 25 individuals, and A. granulatus giving birth to litters of up to eight. At least some populations have relatively few females pregnant during any given year. Females, isolated from males, have demonstrated the ability to produce embryos without sperm, a characteristic that also occurs in other snake lineages. File snakes have very loose skin and poor muscle tone, probably an adaptation to their highly aquatic life style. They also have a larger blood volume than other snakes of a comparable size, allowing them to store more oxygen so they can spend more time underwater. |
 |
The Arafuraen File Snake Acrochordus arafurae McDowell 1979 inhabits eastern Indonesia, New Guinea, and northern Australia in the coastal areas of Northern Territory and Queensland. This specimen was photographed near Darwin, NT, Australia.
|
 |
The Elephant Trunk Snake, Acrochordus javanicus Hornstedt, 1787. Photographed in Thailand. Adults can reach 2.9 m and they have a very robust body form. Elephant trunk snakes inhabit Indochina and Indonesia and prefer stagnant or slow moving water. Fish form most, if not all of the diet. They appear to use holes in banks and they may leave the water during heavy rains. Females have litters of 6-52. In some studies females reproduce once every three years or more, others suggest that females reproduce more frequently, with 66% of the population gravid in any given year. In Indonesia this snake is known as the Karung and is heavily hunted. See: Shine et al. 1995. Journal of Herpetology 29:352-360.
|
 |
 |
|
| All text and photographs copyright © John C. Murphy. All rights reserved worldwide. The content of this site is made available for purposes of researching images offered for license by John C. Murphy. No image is to be copied, duplicated, modified or redistributed in whole or part without the prior written permission of JCM Natural History Photography. Email: jcm@jcmnaturalhistory.com |
|