Major Group: Insecta
Order: Coleoptera
Family: Hydrochidae (formerly within Hydrophilidae)
Genus: Hydrochus
This family is represented by a single genus worldwide, Hydrochus. |
Descriptive Features:
Adults
antennae 7- to 9-segmented with 3- or 4-segmented club
2nd segment of maxillary palpi slender
body narrow
elytra strongly punctate, exposing less than 2 complete abdominal tergites
prothorax without notopleural sutures, ventral portion of the notum, (hypomeron) on each side joined directly to the sternum by notosternal suture
pleuron reduced and concealed
abdomen with more than 3 ventrites
ventrite 1 not divided by hind coxae
meso- and metasternae without a continuous common keel
basal segment of hind tarsi shorter than 2nd
size: 0.5-7.0mm
Larvae
labrum completely fused to head capsule
labial palps 2-segmented
apex of mandible unidentate
maxilla with stipes longer than wide
mesal surface of mandibular base with pubescent lobe
gular sutures separate
abdominal tergum 8 usually subterminal, forming with segment 9 a spiracular chamber housing enlarged 8th spiracles
legs present
size: |
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Hydrochus larva |
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Hydrochus adult |
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Taxonomic Checklist: Species
Hydrochus abditus Watts
Hydrochus adelaidae Blackburn
Hydrochus aenigmatis Watts
Hydrochus aschnakiranae Makhan
Hydrochus atratus Watts
Hydrochus australis Motschulsky
Hydrochus burdekinensis Watts
Hydrochus cucullatus Watts
Hydrochus decorus Watts
Hydrochus euryspleuron Watts
Hydrochus gitaraiae Makhan
Hydrochus granicollis Lea
Hydrochus horni Blackburn
Hydrochus imamkhani Makhan
Hydrochus interioris Blackburn
Hydrochus kunarajahi Makhan
Hydrochus lateviridis Blackburn
Hydrochus macroaquilonius Watts
Hydrochus multicolor Lea
Hydrochus numerosepunctatus Watts
Hydrochus obscuroaeneus Fairmaire
Hydrochus obsoletus Lea
Hydrochus radjiei Makhan
Hydrochus simplicicollis Lea
Hydrochus umbratilis Watts |
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Distribution: Australia wide
Sensitivity Rating: SIGNAL grade 4
Functional Feeding Group: shredders (adults), unknown (larvae) |
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Wakool River on Wakoola, NSW |
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Ecology: No Australian larvae are known.
Instream habitat: Adults of Hydrochidae species are common wherever there is permanent water, living in a wide range of habitats from stagnant pools to gravel edges of major rivers. They are usually found amongst vegetation in gently flowing or still waters.
Feeding ecology: Hydrochus beetles are herbivores and detritivores feeding on parts of plants, periphyton and detritus.
Habit: Hydrochus adults can’t swim. They crawl around on water plants, submerged wood and other surfaces.
Life history: |
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Information Sources: Watts 2002, Williams 1980, Gooderham & Tsyrlin 2002
Key to Species: Watts 1999 (adults) |
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