Stonefly (Zelandobius)

Taxonomic group

Gripopterygidae: Zelandobius

Diagnostic features

Zelandobius stonefly nymphs have a rosette of anal gills between the cerci (“tails”). There are several species but they tend to be a uniform brown colour. They lack the hairy legs of Zelandoperla, the pale markings of Acroperla or Nesoperla, the subanal lobe spines of Megaleptoperla, or the thoracic lobes of Taraperla.

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

[Zelandobius illiesi]. Image: Stephen Moore Image — Zelandobius illiesi. Image: Stephen Moore

Typical habitats

Zelandobius nymphs can be found in a wide range of stony streams and rivers all over the country.

Feeding

They are thought to be “collector-gatherers”, feeding on a range of organic matter accumulating on stream beds.

Indicator value

Hard bottom: 5
Soft bottom: 7.4

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

Zelandobius species can be found in streams of moderate to good water quality. They have tolerance values of 5 (hard bottom sites) and 7.4 (soft bottom sites).