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 Major Groups | Gastropoda (snails) | Hygrophila (snails) | Planorbidae


Major Group: Gastropoda
Order: Hygrophila

Descriptive Features:

  • true molluscan gill lost, replaced by various types of secondary gills in some groups
  • position of eyes relative to tentacles variable, usually at inner bases or at middle of bases
  • hermaphroditic (simultaneous or protandric)
  • operculum absent
  • mantle cavity modified as pulmonary cavity
  • head and snout spread laterally
  • radula with many tooth rows (most teeth rather similar)
  • operculum absent
  • eyes on inner side of tentacle bases
  • shell coiled, sinistral, flat to ovate or elongate, spire sunken, flat or short to long
  • mantle edge simple, with pseudobranch
  • Size:

    Glyptophysa sp.


    Gyraulus sp.

    Taxonomic Checklist: Genera
    Amerianna 4? species
    Ancylastrum 2 species
    Bayardella 2 species
    Ferrissia 2 species
    Stimulator consetti Iredale
    Glyptophysa 11 species
    Gyraulus 10 species
    Helicorbis 2 species
    Isidorella 5? species
    Kessneria papillosa Walker & Ponder
    Leichhardtia sisurnius Walker
    Planorbarius corneus Linnaeus
    Note: plus 1 undescribed genus and several undescribed species

    Distribution: all states

    Sensitivity Rating: SIGNAL grade 2

    Functional Feeding Group: scrapers


    Dobson Lake outflow, Mt Field NP Tas

    Ecology: Instream habitat: Planorbidae species occur in slow-moving and still waters where they are found amongst macrophytes and algae.
    Feeding ecology: Planorbid snails feed macrophytes and algae.
    Habit: Isidorella newcombi is able to aestivate in the mud when conditions become unfavourable.
    Life history: Planorbidae species are hermaphrodites capable of self-fertilisation. They reproduce at least once per year.


    Information Sources: Ponder 2013, Smith 1992, 1996, 2002c, Walker & Ponder 2001, Gooderham & Tsyrlin 2002, Stevens et al. 1996, Sloane & Norris 2002
    Key to Genera: Smith 1996
    Key to Species: Ponder et al. 2000 (NSW), Smith & Kershaw 1981 (Tas)

    Planorbidae species fall into three groups by shell type; freshwater limpets (patelliform), flat spirals (planate taxa) and elevated spirals (non-planate taxa)

    Ferrissia petterdi 

    freshwater limpets

    Gyraulus sp. 

    flat spirals

    Glyptophysa sp. 

    elevated spirals