Isopod

 The lelt is commonly five to seven inches in length. It is white, and long-finned. It swims slowly and smoothly, its fins moving the water very little, which apparently contributes to its own concealment in a blind environment and makes it easier to detect the vibrations of its prey, any of several varieties of tiny segmented creatures, predominantly isopods.

Tribesmen of Gor     Book 10     Page 247

These, in turn, become food for various flatworms and numerous tiny segmented creatures, such as isopods, which, in turn, serve as food for small, blind, white crayfish, lelts and salamanders.

Tribesmen of Gor     Book 10     Page 249

It swims slowly, conserving its energy, not alerting its prey, commonly flatworms and tiny segmented creatures, predominantly isopods.

Tribesmen of Gor     Book 10     Page 256