Airbreathing catfish

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Airbreathing Catfishes
Clarias gariepinus
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Actinopterygii Order: Siluriformes Family: Clariidae
Genera
Bathyclarias Channallabes Clariallabes Clarias Dinotopterus Dolichallabes Encheloclarias Gymnallabes Heterobranchus Heteropneustes Horaglanis Platyallabes Platyclarias Tanganikallabes Uegitglanis Xenoclarias

Airbreathing catfishes are fishes comprising the family Clariidae of Order Siluriformes, part of the Actinopterygii (ray-finned fishes). There are about 14 genera and 100 species of clariids. All the clariids are freshwater species.^[1]

Airbreathing is accomplished with a labyrinthic organ arising from the gill arches ('labyrinth catfishes'). Some species are capable of travelling short distances on land ('walking catfishes'). This has allowed such fish as Clarias batrachus to be an invasive species in Florida.^[1]

The dorsal fin base is very long and is not preceded by a fin spine. The dorsal fin may or may not be continuous with the caudal fin, which is rounded. Pectoral and pelvic fins are variously absent in some species. There are usually four pairs of barbels. Some fish have small eyes and reduced or absent pectoral and pelvic fins for a burrowing lifestyle. A few species are blind.^[1]

Heteropneustidae containing the genus Heteropneustes is considered by some to be a separate family and by others to be a subfamily. Their body is elongate and compressed with a greatly depressed head. They have a long air sac that serves as a lung that extends from the gill chamber. The dorsal fin is short and has no spine. The pectoral fins have an associated venom gland and is considered dangerous.^[1]

With Heteropneustidae and Clariidae as separate family, a recent paper groups these families into a superfamily called Clarioidea. Relationships of clarioids to other families remains uncertain.^[2]

[edit] References

1. ^ ^{a b c d} Nelson, Joseph S. (2006). Fishes of the World. John Wiley & Sons, Inc. ISBN 0-471-25031-7. 
2. ^ Sullivan, JP; Lundberg JG; Hardman M (2006). "A phylogenetic analysis of the major groups of catfishes (Teleostei: Siluriformes) using rag1 and rag2 nuclear gene sequences". Mol Phylogenet Evol. 41 (3): 636-62.