Rhyacichthyidae

Rhyacichthyidae (loach goby; subclass Actinopterygii, order Perciformes) A possibly monospecific family (Rhyacichthys aspro) of freshwater fish that have a flattened head and belly, a low-slung mouth, and small eyes. The two dorsal fins are well separated; the tail fin and pectoral fins are rather large. The anterior part of the body, together with the pelvic fins, form a type of suction device which enables the fish to secure its position in fast-flowing hill streams. The structure of this suction device is similar to that found in the true hillstream loaches (Homalopteridae). There are one or two species, distributed widely in south-east Asia. The name ‘loach goby’ is perhaps unfortunate, as the fish is neither a loach nor a globy.