European cave-dwelling aquatic salamander with permanent external gills; SYN. Proteus anguinus.
Cave-dwelling aquatic salamander Proteus anguinus, the only European member of the family Proteidae, the other members being the North American mudpuppies. Olms are found in underground caves along the Adriatic seaboard in Italy, Croatia, and Yugoslavia. The adult is permanently larval in form, about 25 cm/10 in long, almost blind, with external gills and under-developed limbs. See neoteny.