Oligochaete worms (Eiseniella)

Taxonomic group

Oligochaeta: Eiseniella

Diagnostic features

Eiseniella tetraeda is a large introduced oligochaete worm found mainly in slow flowing streams. Like other oligochaetes they are visibly segmented, but unlike other freshwater oligochaetes they are squarish in cross section, particularly towards the tail end of the body.

[Eiseniella]. Image: Stephen Moore Image — Eiseniella. Image: Stephen Moore

[Eiseniella tetraeda]. Image: Stephen Moore Image — Eiseniella tetraeda. Image: Stephen Moore

Typical habitats

Eiseniella can be common in farmland streams, but we have not found them in the highly polluted sites where smaller tubificid worms can be abundant.

Feeding

They are deposit feeders, collecting fine organic matter from bottom sediments.

Indicator value

Hard bottom: unassigned; general oligochaete value 1
Soft bottom: unassigned; general oligochaete value 3.8

The tolerance values (ranging from 0 to 10) give an indication of which are the sensitive taxa (values of 8 or more) and which are the tolerant taxa (values of 3 or less). For more information see: Indicator species

Eiseniella are associated with soft bottom streams, but they are not as pollution tolerant as other oligochaetes. This genus has not been assigned tolerance values but the oligochaete worms have low tolerance values of 1 (hard bottom sites) and 3.8 (soft bottom sites).