Aquatic Invertebrates of Montana

Haplotaxis gordioides (Hartman)

Recognition

A very distinctive oligochaete that superficially resembles a horsehair worm. The chaetae are simple-pointed and occur 1 per bundle, unlike any other Oligochaeta. The ventral chaetae are stout and strongly curved toward the apex. The dorsal chaetae are smaller and may be absent for much of the length. The prostomium extends far in front of the mouth.

Summary

This is primitive oligochaete that may be very long (up to about 400 mm), but still quite thin (up to about 2 mm). It normally lives in groundwater and is expected in caves and springs as well as streams with groundwater influence. Mature specimens are not yet known from North America and the species is therefore assumed and not really firmly establised. There may be more species named once collections of mature worms become available.

Distribution

A holarctic species that is reported from many parts of North America and it has already been collected in Montana.