Aquatic Invertebrates of Montana

Eiseniella tetraedra (Savigny)

Recognition

A large, thick-bodied aquatic worm with a thick clitellum on segments 22 through 27 or maybe a couple less until fully mature. The body beyond the clitellum is fairly square. Like all lumbricids, there is a well-formed gizzard at the beginning of the intestine.

Summary

This is a small earthworm, being just about big enough to get on a fish hook, which makes it one our biggest aquatic oligochaetes. Montana specimens frequently reach about 45 mm long and about 2 mm wide.

Distribution

It is a widespread species, at least in North America.