While in a big box sporting goods store I overheard a guy talking about blue crabs that were living in an inland freshwater pond with no connection to saltwater. Now I wish I’d gone over and introduced myself. Has anybody ever heard of such a thing?
It actually happens frequently. They sometimes come in the spillways. I’ve personally seen them climb the dikes from salt to fresh. When inside the ponds they can grow very large and in good numbers. I guess the things that feed on he them are few in fresh water.
I can’t see them living long term in that environment. They need a lot of calcium to maintain their exoskeleton. Maybe Barbawang will see this and chime in. I don’t know if crabs absorb calcium straight from the water column, or if they get it mainly via dietary means, but either way, I’m skeptical that most freshwater impoundments would have sufficient calcium (or even magnesium) levels to support their exoskeleton.
… The Cross of Christ is the anvil upon which the hammer of evil wore itself out.
You ever seen the Land Crabs in South Florida? Where do they get their calcium from?
http://edis.ifas.ufl.edu/pdffiles/UW/UW01300.pdf
quote:
Originally posted by EasyYou ever seen the Land Crabs in South Florida? Where do they get their calcium from?
http://edis.ifas.ufl.edu/pdffiles/UW/UW01300.pdf
The article says they “return to the sea only to drink or breed”. That’s where 
I’m not saying that NO crab can live in freshwater. There are species of fiddlers you can buy at Tideline Aquatics in Hanahan that are straight freshwater. I’m just skeptical that blues can do it in a reproducing population.
And of course I could be wrong. I’m not a marine biologist, I just play one on the internet.
… The Cross of Christ is the anvil upon which the hammer of evil wore itself out.
Matt; they must drink a lot of water! When they head for water to breed, they will stack up against buildings, fences and anything in their way. They have shells so hard they have been known to cause flat tires on cars when hit crossing roads! In the 70’s I’ve seen them stacked up on the chain link fencing, we had around missile sites near Miami.
I’ve heard that they are edible. If so, just set up some crab pots in the back yard… right?
… The Cross of Christ is the anvil upon which the hammer of evil wore itself out.
They actually have a season to catch them now! The Cubans around Miami used to pick them up and put them is cages and feed them, to make them taste better!
quote:
Originally posted by Redfish_mattquote:
Originally posted by EasyYou ever seen the Land Crabs in South Florida? Where do they get their calcium from?
http://edis.ifas.ufl.edu/pdffiles/UW/UW01300.pdf
The article says they “return to the sea only to drink or breed”. That’s where
I’m not saying that NO crab can live in freshwater. There are species of fiddlers you can buy at Tideline Aquatics in Hanahan that are straight freshwater. I’m just skeptical that blues can do it in a reproducing population.
And of course I could be wrong. I’m not a marine biologist, I just play one on the internet.
… The Cross of Christ is the anvil upon which the hammer of evil wore itself out.
You are wrong.
Well, SLACK_ Line, certainly clarified the subject!
First time I’ve seen the blue land crab. Watched a show on tv last year that showed the read ones. That was a sight to see. The streets were totally covered from one side to the other.
16’ Bonito 65 Johnson
There is calcium and Magnesium in fresh water. That is what fresh water clams, muscles, crayfish, snails, etc use for their shells.
Wellcraft V-20 sportfish with a 200 Evinrude
late to the party as usual… i’ve seen them in goose creek reservoir, not hard to climb over the dam there, and I can attest that they get huge in freshwater, and impoundments with some salinity too.
as for the exoskeletal ingredients, i’m no chemist and never thought about it before… but steely’s observation makes sense. no idea if they could survive through molting and reproduction in pure fresh, I’ve been curious about that too.
always wondered if land crabs were good to eat, saw some when I was a kid in the keys that I was completely amazed by and followed around for hours.
quote:
Originally posted by steelytomThere is calcium and Magnesium in fresh water. That is what fresh water clams, muscles, crayfish, snails, etc use for their shells.
Wellcraft V-20 sportfish with a 200 Evinrude
I’m speaking mostly from speculation, but also notice that the vast majority of freshwater calcium/magnesium consumers are quite small.
I’m skeptical that most of our inland impoundments (those with no tidal influx) could harbor a reproducing population of blue crabs. Most of our freshwater impoundments aren’t very high in minerals (calcium/magnesium content), and the tannins in many of them are likely to be hostile to proper growth and molting. Obviously I could be wrong. I’m not a marine biologist, I just play one on the internet.
I am, however, speaking from a lifetime of hobby-level marine biology in reef and planted aquarium keeping. In other words, I like to glue animals to rocks and bake them under high powered LEDs.
… The Cross of Christ is the anvil upon which the hammer of evil wore itself out.