Hydrophis semperi
From Wikipedia, the free encyclopedia
| Philippine Freshwater Sea Snake | ||||||||||||||||
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| Hydrophis semperi (Garman, 1881) |
Hydrophis semperi, known in some circles as Garman's sea snake,[2] is a rare sea snake found only in a single lake on the island of Luzon in the Philippines. It is noted for being one of two known species of sea snake (and the only one in its family) that is known to be found almost-exclusively in freshwater.[3]
H. semperi is usually classified in the subfamily Hydrophiinae of the family Elapidae[1], although in some classification schemes, it and the rest of the "true" sea snakes are instead grouped in the family Hydrophiidae.[4]
Like all "true" sea snakes, it is a rather heavyset snake, elongated with a small head. It possesses the characteristic flattened, paddle-like tail found in the members of its subfamily. This particular species is considered short in comparison to the rest of the family; adult specimens of H. semperi that have been caught were in the realm of 50 cm to 70 cm in length. The snake is colored much like a typical sea snake, having a dark blue or black body with alternating yellow (sometimes white) bands encircling its body. Like its close relatives, its nostrils are located almost dorsally, with valves that prevent water from entering its nasal (and oral) cavities when the snake is submerged.[5]
This snake is known to be found only in the waters of Lake Taal (formerly known as Lake Bombon) in the province of Batangas in the Philippines. It is unusual for being the only freshwater sea snake in the country. It lives the entirety of its life within the confines of the lake, feeding and breeding in its slightly acidic waters. The lake itself is a volcanic crater lake, formerly saltwater but its waters gradually lost its salinity after the lake was closed off from the sea by an eruption in the 16th century. It is this unique aspect of the lake's formation and history that led to the evolution of several once-saltwater species, including H. semperi. Thus, this species is relatively young, having been accustomed to freshwater for less than a millennium.
As with "true" sea snakes, H. semperi is piscivorous, feeding primarily on the numerous fish species that are known to dwell in Taal Lake's murky waters. Very little is known about the snake's life history, including its ecology and breeding cycles.
Since so little is known about the species' reproductive habits, there have been little-to-no estimates of the snake's population. Like many other species endemic to the lake, it is vulnerable as a species to any anthropogenic effects on the lake's ecosystem, both directly and indirectly. Pollution is always a major issue when it comes to enclosed bodies of water with numerous surrounding human settlements. The numerous commercial establishments, towns and plantations dumping chemicals and sewage into the lake, combined with the dense population of fish farms in the lake's waters may yet have an adverse effect on the health of the species as a whole. In addition, while the snake itself has no commercial value and is not harvested, it suffers from the typical human stigma that is often attributed to snakes. Fishermen that frequently encounter the docile snakes have been known to kill the snakes simply because of what they are.[3]
The snake was named for Carl Semper, a German ecologist who discovered the species in the mid-1800s. It is also sometimes referred to as Garman's sea snake.[2] Locally, the snake is known as duhol.[3]
[edit] References
- ^ a b Hydrophis semperi (TSN 700554). Integrated Taxonomic Information System. Retrieved on 13 January 2007.
- ^ a b Hydrophis semperi. UNEP-WCMC Species Database. United Nations Environment Programme. Retrieved on 2007-02-02.
- ^ a b c Diesmos, Arvin C.; Rafe M. Brown, Marefe C. Lagda and Norydel F. Tresnado (2005-03-07). The "sea" snake of Taal Lake. Features. [Haribon Foundation for the Conservation of Natural Resources]. Retrieved on 2007-02-02.
- ^ Bischoff, Joe; Mikhail Domrachev, Scott Federhen, Carol Hotton, Detlef Leipe, Vladimir Soussov, Richard Sternberg and Sean Turner. Hydrophis semperi. National Center for Biotechnology Information Database. U.S. Library of Medicine. DOI:ID: 66179 Taxonomy ID: 66179. Retrieved on 2007-02-02.
- ^ Uetz,Peter, EMBL Reptile Database: Subfamily Hydrophiinae (Sea Snakes). Family Elapidae (cobras, coral snakes, and seasnakes etc.). European Molecular Biology Laboratory (EMBL) Heidelberg 2006-04-04
