Indostomus
Indostomus is the sole genus of the monogeneric family Indostomidae, indigenous to freshwater habitats in Indochina.[1] The indostomids were long considered to belong in the stickleback order Gasterosteiformes, as close relatives of seahorses and pipefishes (family Syngnathidae). Molecular analyses consistently find that syngnathids do not belong with Gasterosteiformes, however, and Indostomus may not be closely related to either group.[2]
| Indostomus | |
|---|---|
 | |
| I. paradoxus in an aquarium | |
| Scientific classification | |
| Kingdom: | |
| Phylum: | |
| Class: | |
| Order: | |
| Family: | Indostomidae Prashad & Mukerji, 1929 |
| Genus: | Indostomus Prashad & Mukerji, 1929 |
Species
The three currently recognized species in this genus are:[3]
- I. crocodilus Britz & Kottelat, 1999
- I. paradoxus Prashad & Mukerji, 1929 (armoured stickleback, pipe fish)
- I. spinosus Britz & Kottelat, 1999
The first indostomid, I. paradoxus, was discovered in the 1920s in a lake in Burma. It was named the armoured stickleback, but is also called paradox fish and Burma stichling. The fish was morphologically unique, so the new family Indostomidae was erected for it. It is 3 to 4 cm in length and much smaller in width and height, similar to the pipefish. The body is extremely thin and cylindrical, especially caudally as it tapers to its thinnest point and ends in a fan-shaped tail fin. The body is thin and twiglike, covered in hard scutes, and bears five spines on its back and six on its operculum. It is a slow-moving, bottom-feeding fish that picks for food in the mud of swamps and rivers.
In the 1990s, two other species were discovered and placed into the genus Indostomus.[4] I. crocodilus lives in Thailand and has habits similar to I. paradoxus. I. spinosus was found in the Mekong River, its tributaries, and adjoining swamps. In 2001, I. tiliosi was listed as a possible new species, but has not yet been officially described.
References
- Froese, Rainer, and Daniel Pauly, eds. (2012). "Indostomidae" in FishBase. October 2012 version.
- Kawahara, Ryouka; Miya, Masaki; Mabuchi, Kohji; Lavoué, Sébastien; Inoue, Jun G.; Satoh, Takashi P.; Kawaguchi, Akira; Nishida, Mutsumi (2008). "Interrelationships of the 11 gasterosteiform families (sticklebacks, pipefishes, and their relatives): A new perspective based on whole mitogenome sequences from 75 higher teleosts". Molecular Phylogenetics and Evolution. 46 (1): 224–236. doi:10.1016/j.ympev.2007.07.009. ISSN 1055-7903.
- Froese, Rainer and Pauly, Daniel, eds. (2012). Species of Indostomus in FishBase. October 2012 version.
- Britz, R. and M. Kottelat. (1999). Two new species of gasterosteiform fishes of the genus Indostomus (Teleostei: Indostomidae). Ichthyol. Explor. Freshwat. 10(4):327-336.
Further reading
- Berra, Tim M. (2001). Freshwater Fish Distribution. San Diego: Academic Press. ISBN 0-12-093156-7