Double gill mayfly (Austronella)

Taxonomic group

Leptophlebiidae: Austronella

Diagnostic features

Austronella mayfly nymphs have a flattened body form, with generally pale colouring, and slender double gills. The prothorax (segment immediately behind the head) widens towards the head.

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

[Austronella]. Prothorax widest near the head. Image: Stephen Moore Image — Austronella. Prothorax widest near the head. Image: Stephen Moore

Typical habitats

Austronella is one of the less commonly recorded mayflies, but their larvae are found in weed bed or stony stream habitats.

Feeding

Leptophlebiid mayflies feed by scraping diatom algae and other organic matter from stone or plant surfaces.

Indicator value

Hard bottom: 7
Soft bottom: 4.7

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

Austronella larvae can be common in weedy streams with only moderate water quality, so they are not a strong indicator of pristine conditions. They have tolerance values of 7 (hard bottom sites) and 4.7 (soft bottom sites).