1. FishLoaches are ray-finned fishes of the suborder Cobitoidei. They are freshwater, benthic (bottom-dwelling) fish found in rivers and creeks throughout Eurasia and northern Africa. Loaches are among the most diverse groups of fish; the 1249 known species of Cobitoidei comprise about 107 genera divided among 9 families. == Etymology == The name Cobitoidei comes from the type genus, Cobitis, described by Carl Linnaeus in his landmark 1758 10th edition of Systema Naturae. However, its origin predates modern zoological nomenclature and derives from a term used by Aristotle to refer to "small fishes that bury... like the gudgeon." == Description == Loaches display a wide variety of morphologies, making the group difficult to characterize as a whole using external traits. They range in adult length from the 23 mm (1 in) miniature eel-loach, Pangio longimanus, to the 50 cm (20 in) imperial flower loach, Leptobotia elongata, with the latter weighing up to 3 kg (6.6 lbs). Most loaches are small, narrow... from wikipedia.org