Acrochordus granulatus

Acrochordus granulatus
Conservation status
Least Concern  (IUCN 3.1) [1]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Suborder:	Serpentes
Family:	Acrochordidae
Genus:	Acrochordus
Species:	A. granulatus
Binomial name
Acrochordus granulatus (Schneider, 1799)
Synonyms [2]
[Hydrus] Granulatus – Schneider, 1799 [Anguis] Granulatus vel Acrochordus – Scheider, 1801 [Anguis] Granulatus – Scheider, 1801 Acrochordus Fasciatus – Shaw, 1802 Pelamis granulatus – Daudin, 1803 Chersydrus [fasciatus] – Cuvier, 1817 [Chersydrus] granulatus – Merrem, 1820 C[hersydreas]. granulatus – Gray, 1825 Chersydrus annulatus – Gray, 1849 Potamophis fasciata – Schmidt, 1852 Chersydrus fasciatus – Duméril, Bibron & Duméril, 1854 Acrochordus fasciatus – Schlegel, 1872 Chersydrus granulatus – Boulenger, 1893 [Chersydrus] g[ranulatus]. granulatus – Loveridge, 1938 Chersydrus granulatus luzonensis – Loveridge, 1938

Acrochordus granulatus is a snake species found from India through Southeast Asia to the Solomon Islands. It is known as the little file snake, marine file snake, ^[3] and little wart snake. ^[4] It is completely aquatic and almost helpless on land. No subspecies are currently recognized. ^[5]

Description

Acrochordus granulatus is the smallest of the three members of the family Acrochordidae, and is commonly called the "little file snake". Acrochordus granulatus is also the only Acrochord that permanently inhabits estuaries as well as coastal seas, dawning its other common name the "marine file snake". ^[6] All members of Acrochordus are completely aquatic and nearly helpless on land, with the exception of A. granulatus. The file snake has hygroscopic skin that retards desiccation, allowing it to travel out of water. ^[7]

As with the other members of the genus, Acrochordus granulatus has uniquely spinose scales with an almost rough texture. ^[8] Members of Acrochordus also possess specialized tubercles with nerve endings on the skin between their scales which provide an extra sensory organ used to feel water movements of prey. ^[9] Acrochordus granulatus also have laterally compressed tails, and they can flatten dorsoventrally to assist in swimming. ^[8] Acrochordus granulatus are the most marine of the Acrochordidae and have specialized sublingual salt glands similar to those found in the true sea snake subfamily Hydrophiinae. Despite this, they are still susceptible to dehydration at sea and rely on freshwater lenses built up on the surface of marine water for freshwater. Members of the true sea snake subfamily Hydrophiinae have been shown to exhibit this same behavior. ^{[10] [11]} Acrochordus granulatus are sexually divergent, with females being slightly larger than males. ^[12]

Geographic range

Found from both coasts of peninsular India though Southeast Asia, the Indo-Australian Archipelago and northern Australia to the Solomon Islands. This includes Bangladesh, Myanmar, Sri Lanka, the Andaman and Nicobar Islands, Thailand, Cambodia, Vietnam, China (Hainan), the Philippines (Luzon, Cebu and Batayan), Malaysia, Indonesia (Sumatra, Java, Borneo, Flores, Timor, Sulawesi, Ternate, Ambon, and coastal Irian Jaya), Papua New Guinea, the Solomon Islands the coast along northern Australia (Northern Territory and eastern Queensland). No type locality was given with the original description, although Smith (1943) gives "India" and Saint-Girons (1972) gives "Inde." ^[2]

Feeding

Harold Voris reports field studies revealing a diet of Gobiodei, Eleotridae, Trypauchenidae, small crustaceans and snails in the straits of Malacca. ^[13] Due to the species' extensive range, the diet likely varies regionally. ^[14] In captivity they have been known fairly non-preferential to take a variety of fish. ^[8]

References

1. Sanders, K.; Murphy, J.; Lobo, A.; Gatus, J. (2010). "Acrochordus granulatus". IUCN Red List of Threatened Species . 2010: e.T176769A7300762. doi: 10.2305/IUCN.UK.2010-4.RLTS.T176769A7300762.en . Retrieved 20 November 2021.
2. McDiarmid RW, Campbell JA, Touré T. 1999. Snake Species of the World: A Taxonomic and Geographic Reference, vol. 1. Herpetologists' League. 511 pp. ISBN   1-893777-00-6 (series). ISBN   1-893777-01-4 (volume).
3. Acrochordus granulatus at the Reptarium.cz Reptile Database . Accessed 16 August 2007.
4. Western Australian Reptile Species at Frank O'Connor's Birding Western Australia. Accessed 20 September 2007
5. "Acrochordus granulatus". Integrated Taxonomic Information System . Retrieved 16 August 2007.
6. Lillywhite, Harvey B.; Ellis, Tamir M. (1994). "Ecophysiological Aspects of the Coastal-Estuarine Distribution of Acrochordid Snakes" . Estuaries. 17 (1): 53–61. doi:10.2307/1352334. JSTOR   1352334. S2CID   83854655.
7. Comanns, Philipp; Withers, Philip C.; Esser, Falk J.; Baumgartner, Werner (November 2016). "Cutaneous water collection by a moisture-harvesting lizard, the thorny devil (Moloch horridus)". Journal of Experimental Biology. 219 (21): 3473–3479. Bibcode:2016JExpB.219.3473C. doi: 10.1242/jeb.148791 . PMID   27807218. S2CID   22725331.
8. Lillywhite, Harvey B. (1996). "Husbandry of the little file snake, Acrochordus granulatus" . Zoo Biology. 15 (3): 315–327. doi:10.1002/(SICI)1098-2361(1996)15:3<315::AID-ZOO10>3.0.CO;2-9.
9. Van Der Kooij, Jeroen; Povel, David (1996). "Scale Sensillae of the File Snake (Serpentes: Acrochordidae) and Some Other Aquatic and Burrowing Snakes" . Netherlands Journal of Zoology. 47 (4): 443–456. doi:10.1163/156854297X00111.
10. Lillywhite, Harvey B.; Heatwole, Harold; Sheehy, Coleman M. (2014). "Dehydration and Drinking Behavior of the Marine File Snake Acrochordus granulatus". Physiological and Biochemical Zoology. 87 (1): 46–55. doi:10.1086/673375. PMID   24457920. S2CID   24775631.
11. Lillywhite, Harvey B.; Sheehy, Coleman M.; Sandfoss, Mark R.; Crowe-Riddell, Jenna; Grech, Alana (2019). "Drinking by sea snakes from oceanic freshwater lenses at first rainfall ending seasonal drought". PLOS ONE. 14 (2): e0212099. Bibcode:2019PLoSO..1412099L. doi: 10.1371/journal.pone.0212099 . PMC   6366689 . PMID   30730972.
12. Shine, Richard (1991). "Intersexual Dietary Divergence and the Evolution of Sexual Dimorphism in Snakes". The American Naturalist. 138 (1): 103–122. Bibcode:1991ANat..138..103S. doi:10.1086/285207. S2CID   84056277.
13. "Acrochordus granulatus (Little filesnake, Marine File Snake)". Animal Diversity Web .
14. Voris, Harold K.; Glodek, Garrett S. (1980). "Habitat, Diet, and Reproduction of the File Snake, Acrochordus granulatus, in the Straits of Malacca". Journal of Herpetology. 14 (1): 108–111. doi:10.2307/1563896. JSTOR   1563896.

Further reading

• Greer, A.E. 2006. Encyclopedia of Australian Reptiles. Australian Museum Online. Accessed 16 August 2007.
• Shine, R. 1991. Australian Snakes, a Natural History. Ithaca, New York: Cornell University Press.
• Smith, M.A. 1943 The Fauna of British India, Ceylon and Burma, Including the Whole of the Indo-Chinese Sub-Region. Reptilia and Amphibia. 3 (Serpentes). Taylor and Francis, London. 583 pp.
• Wall, Frank 1921 Ophidia Taprobanica or the Snakes of Ceylon. Colombo Mus. (H. R. Cottle, government printer), Colombo. xxii, 581 pages

External links

• Acrochordus.com. Accessed 16 August 2007.
• Image of Acrochordus granulatus at the Institute of Toxicology and Genetics. Accessed 16 August 2007.
• Videos of A. granulatus feeding in captivity.
• Little Filesnakes at Life is Short but Snakes are Long