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 Major Groups | Insecta (insects) | Ephemeroptera (mayflies) | Oniscigastridae


Major Group: Insecta
Order: Ephemeroptera
Family: Oniscigastridae
Genus: Tasmanophlebia
This family is represented in Australia by a single genus, Tasmanophlebia.

Descriptive Features:

  • head small, hypognathous
  • length of antenna a little less than width of head
  • legs medium length, tibia shorter than tarsus, tarsal claws smooth
  • abdomen dorsoventrally flattened
  • abdominal segments 1-9 with flattened lateral flange and strongly projecting posterolateral angle
  • abdominal segments 1-5 (at least) with dorsal protuberances along midline
  • gills present on abdominal segments 1 to 4, all gills with margins entire,
  • operculate gills on segment 1, covering the gills on segments 2-4, inner margins of operculate gills widely separated
  • all caudal filaments with lateral setal fringes, although setae on outer margins of outer caudal filaments shorter and restricted to apical half
  • Total length: 12 - 15 mm

    Tasmanophlebia sp.

    Taxonomic Checklist:
    Tasmanophlebia lacuscoerulei Tillyard
    Tasmanophlebia lacustris Tillyard
    Tasmanophlebia nigrescens Tillyard

    Distribution: NSW, Vic, Tas, SA, ACT

    Sensitivity Rating: SIGNAL grade 8

    Functional Feeding Group: gathering collectors


    Ovens River, Peechelba Vic

    Ecology: Instream habitat: Oniscigastridae species have been recorded from a wide range of habitats, from high altitude lakes and streams to small coastal streams. They are usually found on sandy substrata and will tolerate a small amount of silt.
    Feeding ecology: Oniscigastrid nymphs are detritivores.
    Life history: Females produce 1500 eggs. Emergence usually takes place at dusk when the mature nymph crawls out of the water just before ecdysis. At peak times large numbers of exuviae (empty nymphal skins) can be found above the water line attached to the sides of boulders or large rocks. There one or two generations per year with the adults emerging between November and March.


    Information Sources: Dean & Suter 1996, Suter & Webb 2012, Peters & Campbell 1991, Gooderham & Tsyrlin 2002, Sloane & Norris 2002
    Key to Species: Suter & Webb 2012
    Key Note: Specimens without wing pads are early instars and cannot be confidently identified at species level.