Major Group: Crustacea Minor Group: Malacostraca Order: Decapoda Family: Hymenosomatidae Genus: Amarinus Species: lacustris This family is represented in Australia by a single freshwater species, Amarinus lacustris Chilton. |
Descriptive Features: cephalothorax dorso-ventrally thin, cuticle not heavily calcified, without hooked setae
dorsal carapace surface flat or nearly flat, often with strong gastro-cardiac groove and contiguous grooves
without orbits or with very incomplete orbits, eyes exposed and a little retractile
antennular fossae shallow and poorly defined, antennae fused with epistome (when present), 2nd segment slender
ischium of 3rd maxillipeds well developed, palp articulating near anterolateral angle of merus
chelipeds not longer than 2x carapace width in females and most males, fingers not bent at an angle to palm
male and female abdomens with not more than 5 segments, excluding telson
Carapace width: 2 - 26 mm |
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Amarinus lacustris |
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Taxonomic Checklist: Amarinus lacustris Chilton |
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Distribution: SA, Vic, Tas
Sensitivity Rating: SIGNAL grade 3. Amarinus lacustris is commonly found in freshwater with higher salinities.
Functional Feeding Group: gathering collectors |
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Murray River, near Hindmarsh Island SA |
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Ecology: Hymenosomatidae species are commonly known as 'false spider crabs'. Instream habitat: Hymenosomatid crabs generally occur in shallow marine coastal waters and estuaries, however, Amarinus lacustris is the only species noted as occurring in freshwater streams and lakes. This species is found in large numbers on snags, amongst vegetation or under and around rocks. Feeding ecology: These crabs are detritivores and omnivores. Habit: The pointed terminal leg segment enables them to climb freely on logs. They are crawlers and burrowers. Life history: |
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Information Sources: Davie 2002b, Gooderham & Tsyrlin 2002, Hawking & Smith 1997 |
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