What True crabs are freshwater?

I am creating a project including all freshwater invertebrates and just need to finish it off with freshwater Hydrozoans, Amphipods and True crabs. Can anyone help me list them?

I don’t know how you want to handle this one, but Rhithropanopeus harrisii is an estuarine species that has been introduced into freshwater reservoirs and is now thriving in them.

There are likely many species of crabs that live in freshwater or brackish water. It is not clear if the brackish water species fit your project. There are crabs farmed in rice paddy fields in Asia in Thailand, Vietnam. The hill streams of Myanmar, Taiwan have freshwater crabs species. If you search through iNat , find those locations that are very inland. Some observations still need identification. In my area, Parathelphusa maculata, Irmengardia johnsoni, Parathelphusa reticulata are found in freshwater streams. The types popular in the pet trade Geosesarma species are land based, tropical forests. There are several species of rice paddy crabs, and Chinese mitten crab.

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There are a great number of freshwater amphipods as well. I can’t recall the exact number at the top of my head (always changing with new taxa described every year), but easily near a thousand in numerous families. There are common surface taxa (Gammarids, Crangonyctids, Hyaelllids, Chiltoniids, etc…); an extreme number of cave taxa (Niphargids, Crangonyctids, Hadziids, etc…), and even terrestrial taxa in the Talitroidea!

A lot of these taxa also include marine taxa (IE: Gammarus spp. can be found in both freshwater and marine environments (some species actually occur in both too!)) so any list would have to go species by species; which might be a bit clunky. depending on your area.

EDIT: It’s roughly around 2,000 described species now; a whole list might be difficult but I may be able to assist with a regional list.

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In the Laurentian Great Lakes Diporeia was, until recently, a keystone species (well, keystone genus, I guess) that played an enormous role in structuring ecosystems. Invasive Dreisenid mussels have drastically reduced their abundance everywhere but Lake Superior. Last I heard, the number of species was still being discussed.

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The project would be for freshwater inverebrates in Victoria, Australia.

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Thanks cannizag. The area would be in Victoria, Australia.

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The most well known freshwater hydrozoans are Hydra, Craspedacusta, and Cordylophora, but there may be others I don’t know of.

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In that case, Bradbury & Williams, 1999 would be a good reference for you. It’s a bit old but covers the basic taxa pretty well. The MDFRC website also has a ton of info. These two sources should cover most of the common families/genera, as well as a majority of species, but several have been described since 1999. And there are hordes of species that remain undescribed.

That being said a lot of these are unique cave/hypogean taxa, the most common 'pods you’ll likely encounter are chiltoniids/paraleptamophopids.

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Yeah! A really cool and unique genus. You are correct, at one point it was thought that there were several species, but it seems molecular analyses suggest shallow distances across the genus’ range, so it seems that D. hoyi is our only valid species.

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Thanks Thomas!

Had a look at the links. Amphipods should be completed!

Just need true crabs now :grinning:

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Sever true crabs are in freshwater. Yet they are not true freshwater crabs. True freshwater crabs lack larval development as evident in marine crabs, they have extensive maternal care and cant live in marine environments for long. I work on true freshwater crabs in South Africa.
Regards
Savel

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There are something like 1300 species of freshwater crab with more being discovered all the time. It’s a paraphyletic grouping, so making an accurate and comprehensive species list is not easy.

Vietnam alone had around identified to species as of 2014, and I know more have been discovered here since then.

These papers may help a bit:

And that’s not including the terrestrial crabs, some of which do rely on freshwater for things like breeding, and therefore could be loosely considered freshwater species.

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That’s very useful information. You might want to update your original message to include it so that you don’t continue to get irrelevant responses. Also, I doubt that there’s anyone who has a list of freshwater invertebrates for Victoria Austrailia. That’s a very specific request. You may need to do the research yourself if you actually must have this list for your project. This information is probably not easy to find in one source and may take many days of research in the literature to find. Are you sure you actually need this list? :slightly_smiling_face:

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Here’s a site that’s specifically that. Not sure how comprehensive it is though:

The Victoria government library has a lot of resources, but it’ll take a good bit of filtering to narrow it down to relevant ones:

The book Freshwater Invertebrates by Ralph H. Miller focuses specifically on SE Australia, but it is from 1996 and as such is probably not up to date. Still a useful resource though.

The National Library of Australia has a copy, as do other places:

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I’m not sure if it holds in other regions, but on South Pacific islands, a number of estuarine crabs in Sesarmidae and Varunidae are also found in purely freshwater streams further inland

I have seen river crabs in the Dominican Republic, which are Epiloboceridae. But that seems to be a Caribbean endemic family.

I am creating a project for Freshwater Invertebrates and need to finish it with freshwater true crabs. Can anyone help me list them?

(Freshwater crabs in Victoria, Australia)