Spiny gilled mayfly (Coloburiscus)

Taxonomic group

Coloburiscidae: Coloburiscus

Diagnostic features

Coloburiscus mayfly nymphs are easily distinguished by the cactus-like gills covering the top of the abdomen. The front and mid legs are very hairy.

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

[Coloburiscus]. Cactus-like abdominal gills. Image: Stephen Moore Image — Coloburiscus. Cactus-like abdominal gills. Image: Stephen Moore

Typical habitats

Coloburiscus larvae are most abundant in stony or gravelly, cold water, well aerated, bush covered streams.

Feeding

They are filter feeders, using their hairy legs to trap drifting food particles (probably both plant fragments and small invertebrates).

Indicator value

Hard bottom: 9
Soft bottom: 8.1

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

High abundances of Coloburiscus are indicative of good habitat and water quality, particularly if other mayflies or stoneflies are common or abundant. They have tolerance values of 9 (hard bottom sites) and 8.1 (soft bottom sites).