Major Group: Gastropoda Order: Hygrophila Family: Planorbidae (formerly Ancylidae) |
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 typically absent, present in 1 basal families
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 limpet-shaped
mantle edge simple, with pseudobranch
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Ferrissia petterdi |
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Taxonomic Checklist: Species Ferrissia petterdi Johnston Ferrissia tasmanica Tenison-Woods Stimulator consetti Iredale |
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Distribution: all states
Sensitivity Rating: SIGNAL grade 4
Functional Feeding Group: scrapers |
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Murray River at Talmalmo, Vic |
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Ecology: Instream habitat: Ferrissia species occur in a wide variety of freshwater habitats, from stagnant pools to fast flowing creeks and rivers. They are found attached to any flat surface, in line with their common name of ‘limpet snail’. Limpet snails can cope with a variety of water speeds and live on rocky substrates, woody debris and amongst macrophytes. Feeding ecology: Limpet snails graze on periphyton. Habit: Life history: Species in the Northern Hemisphere are hermaphroditic but cannot self-fertilise as the sperm and ovum are kept separately within the body. The life span is about one year. |
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Information Sources: Ponder 2001, 2013, Smith 1992, 1996, Smith & Kershaw 1981, Sloane & Norris 2002 Key to Genera: none (Stimulator only occurs in NW WA) Key to Species: Ponder et al 2000 (NSW, Ferrissia), Smith & Kershaw 1981 (Tas, Ferrissia) |
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