Allotoca is a genus of splitfins that are endemic to west-central and southwest Mexico, where restricted to the Lerna–Chapala–Grande de Santiago, Ameca and Balsas river basins, as well as various endorheic lake basins in Michoacán and Jalisco (Pátzcuaro, Zirahuén, Cuitzeo, Magdalena and others).

[4] The largest Allotoca is up to 12 cm (4.7 in) long, but most species only reach between half and three-quarter that size.

[3] Unusually, A. catarinae is probably the result of an ancient translocation by humans in the pre-Columbian era (similar ancient human-assisted translocations are known from certain birds in Mexico).

[1] FishBase recognizes eight species in this genus,[3] but their taxonomy is complex and in need of a review.

[1] One of the species recognized by FishBase, A. regalis, is distinctive and sometimes placed in its own genus Neoophorus.