Stonefly (Spaniocerca)

Taxonomic group

Notonemouridae: Spaniocerca

Diagnostic features

Spaniocerca stonefly nymphs have no gills between the cerci (“tails”), they have a hair fringe around the pronotum (first segment behind the head) and unlike Halticoperla the hind legs are not much broader than the fore legs.

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

[Spaniocerca]. Hair fringe around the pronotum. Image: Stephen Moore Image — Spaniocerca. Hair fringe around the pronotum. Image: Stephen Moore

Typical habitats

Spaniocerca nymphs are rarely found in abundance, but they tend to occur in gravelly or stony, fast flowing, cold water streams.

Feeding

Like most other stoneflies they may feed on a range of organic matter including decomposing vegetation, algae and other microscopic organisms in streambed biofilms.

Indicator value

Hard bottom: 8
Soft bottom: 8.8

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

Spaniocerca nymphs are an indication of good habitat and water quality conditions, especially if other mayfly or stonefly groups are abundant. They have tolerance values of 8 (hard bottom sites) and 8.8 (soft bottom sites).