Results for “relict”

Endemic to a handful of natural springs in the Río Verde valley, San Luis Potosí state, Central Mexico. The valley is believed to have once been filled by a large lake and the relict springs are part of the elevated Río (river) Verde basin which later drains into the much larger Río Pánuco system. Much of the aquatic fauna found in the valley is endemic to the area but in many cases threatened by introduced species.

This little-known, relict species possesses some unique morphological and behavioural traits when compared with its congeners and the genus Kosswigichthys was erected for it in the original description. It has a much more elongate body profile than other Aphanius spp., almost total absence of scalation on the body and three rows of conical (as opposed to tricuspid in all other species) teeth which set it apart. Work by Franz and Villwock in the 1970s revealed it to be a member of Aphanius and showed ...