The fish also lacks eyes, instead having various sensory organs for taste, smell, and touch; these can help it to orient itself in the total darkness and locate food.

[2] R. reddelli is known from a single cave system in Mexico through which flows an underground stream about 3 mi (4.8 km) long.

The cave is near San Antonio Cañada, in the Sierra Madre de Oaxaca southeast of Mexico City.

With this limited and erratic food supply, the fish has a low metabolic rate and stores fat in its tissues.

It exhibits parental care by keeping its newly hatched young in its mouth to prevent predation.