Chaca (genus)

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Chaca
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Siluriformes
Superfamily: Siluroidea
Family: Chacidae
Bleeker, 1858
Genus: Chaca
Gray, 1831
Binomial name
Chaca bankanensis
Bleeker, 1852
Chaca burmensis
Brown & Ferraris, 1988
Chaca chaca
(Hamilton, 1822)

Chaca is the only genus in the catfish family Chacidae. These fish are commonly known as squarehead catfishes, frogmouth catfishes, or angler catfishes.[1] These unusual fish have a sedentary lifestyle and spend much of their time immobile.

Contents

[edit] Taxonomy

The first species of this genus was first described as Polystacus chaca in 1822 by Hamilton.[2] In 1831, the genus Chaca was erected for this species by John Edward Gray.[3] Later, Pieter Bleeker described the second species, C. bankanensis, in 1852.[4] C. burmensis was described most recently in 1988 by Brown and Ferraris.[5][6] C. burmensis is more closely related to C. chaca than to C. burmensis.[5]

Chaca is the sole genus in the family Chacidae. The monophyly of this family is supported by a number of skeletal characters.[5] This family is one of many families in the superfamily Siluroidea, which also includes Siluridae, Malapteruridae, Auchenoglanididae, Plotosidae, Clariidae, and Heteropneustidae. Chacidae has a close relationship with Plotosidae and Clariidae.[7]

The name Chaca is derived from the sound these fish make when it pulled out of the water; when removed from the water, they will rapidly repeat the sound "chaca".[3] Only C. chaca makes these sounds; the other species do not.[8]

[edit] Distribution and habitat

Chaca species are found in freshwater from eastern India to Borneo. C. chaca is found in the Ganges-Brahmaputra River system of India and the Ayeyarwady River of Myanmar.[3] C. bankanensis originates from the Sundaland region.[3] C. burmensis is found in the Sittang River in Myanmar and possibly the Ayeyarwady drainage.[5]

C. chaca is found in rivers, canals, and ponds of grassland, scrubland, deciduous forest, and rainforest habitats.[3][2] On the other hand, C. bankanensis is only found in the rainforest, where it inhabits peat.[3][4]

[edit] Appearance and anatomy

Thse fish have a broad head that is long and flattened. The mouth is terminal and very wide.[3] There are three or four pairs of barbels, though if the nasal barbels are present they are minute.[7] These fish grow to a length of about 20 centimetres (8 in).[2][4][6]

The dorsal fin spine is short and strong dorsal and pectoral fin spines that are serrated; though small, they are strong enough to inflict wounds. This provides the fish with a defense.[3]

[edit] Ecology

These fish live in soft substrates where they will bury themselves as camouflage, both for protection and to feed.[2] These fish are ambush predators. They feed on prey such as small fish, including cyprinids and cyprinodontids.[3] They will lie in wait, well camouflaged, in preparation for prey to swim by. Sometimes, they use their maxillary barbels to lure prey fish closer to its mouth, similar to a worm jerking in the water.[3] This behavior is contested by some aquarists who do not observe this behavior.[8] When the catfish is ready to strike, the Chaca will open its large mouth rapidly, creating a vacuum that pulls in water and its prey, which may be up to half the fish's own length.[3] These fish are also able to use this large mouth as a means of propulsion; when frightened, they will gulp a large amount of water and expel it through their gills.[8]

[edit] In the aquarium

Chaca species are occasionally available as aquarium fish. These fish are nocturnal and are usually inactive. It is no surprise, with their large mouths, that these fish should not be maintained with smaller fish.[9] A bizarre phenomenon is shown in that Chaca appear to lower the pH of the water, and so maintenance of water chemistry is necessary.[8] These fish have been bred in captivity.[8]

[edit] References

  1. ^ Chacidae (TSN 164133). Integrated Taxonomic Information System. Retrieved on May 8, 2007.
  2. ^ a b c d "Chaca chaca". FishBase. Ed. Ranier Froese and Daniel Pauly. May 2007 version. N.p.: FishBase, 2007.
  3. ^ a b c d e f g h i j k Roberts, Tyson R. (1982). "A Revision of the South and Southeast Asian Angler-Catfishes (Chacidae)". Copeia 1982 (4): 895–901. doi:10.2307/1444100. 
  4. ^ a b c "Chaca bankanensis". FishBase. Ed. Ranier Froese and Daniel Pauly. May 2007 version. N.p.: FishBase, 2007.
  5. ^ a b c d Brown, Barbara A.; Ferraris, Carl J., Jr. (1988). "Comparative Osteology of the Asian Catfish Family Chacidae, with the Description of a New Species from Burma" (PDF). American Museum Novitates (2907): 1–16. 
  6. ^ a b "Chaca burmensis". FishBase. Ed. Ranier Froese and Daniel Pauly. May 2007 version. N.p.: FishBase, 2007.
  7. ^ a b Nelson, Joseph S. (2006). Fishes of the World. John Wiley & Sons, Inc.. 
  8. ^ a b c d e Catfish of the Month::March 2001 (2006-10-03). Retrieved on 2007-05-08.
  9. ^ Axelrod, Herbert R. (1996). Exotic Tropical Fishes. T.F.H. Publications. 
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