Crab help please????

Question

i really want a pet crab

the only crabs available where i live are saltwater ones from the wild

1. would they survive in freshwater

2. would they survive in no water (still damp)

3. what do they eat

4.are they ok with silica sand

they are just basic small 1 inch crabs

Answer 1

This might take a bit to explain properly, but I'll make it as brief as I can.  

1. Can they survive in freshwater?

---Probably not, but it depends on the species of crab you're dealing with.  The reason that most freshwater animals only live in freshwater, and vice versa for salt water, has to do with something called osmoregulation.  I won't bore you with the details; but freshwater animals have adaptations that allow them to retain body salts and expell large amounts of fresh water; saltwater creatures work the opposite way, retaining freshwater, and expelling large amounts of salts.  Here's a good link to explain things in further detail if you're curious: http://www2.hawaii.edu/~delbeek/delb11.h...

Having said that, there are some animals that can move back and forth between fresh and salt water and routinely do so.  Blue crabs, which are very common along the eastern and gulf coasts of North America often spend large amounts of time in freshwater and can even reproduce in fresh water.  Fiddler crabs are quite common in brackish water and do quite well in freshwater as well.  Most marine crabs are not capable of this transition though, so you'll need to know what kind of critter you're dealing with first.  If you can get a decent picture of one, I may be able to help.

2. Would they survive in no water?

---While it is true that many crustaceans can survive prolonged periods out of water, only the various species of "land crabs" are truly equipped for a terrestrial existence.  Your best bet here is to duplicate whatever environment you find them in.  Even though you may find them scuttling around the rocks along the shore, if you aren't seeing them inland (let's consider "inland" to be more than 15 or 20 meters from water), it's best to consider them as aquatic animals that need continuous access to water.

3. What do they eat?

---This is an easy one, as crabs are all pretty much generalists when it comes to food.  They have little taste receptors all over their body (particularly concentrated in their "feet"), and they are constantly looking for little edible morsels to munch on.  Any kind of fish food will work fine, and an occaisional meaty treat is always relished.

4. Are they ok with silica sand?

---Silica sand should be just fine.  While silica dust can cause diseases in animals with lungs, it shouldn't harm your crab at all.  If your little guy is a burrower, something a little more coarse (playbox sand, or beach sand) would probably be a better choice though.

Again, if you can get me a decent pic of one I can probably help figure out some of these answers more precisely; but if not, just do your best to duplicate whatever environment you find them in.  Crabs are pretty tough little critters, but they do have some basic needs you'll need to address too.  Good luck to ya!

Answer 2

no, they won't survive in freshwater. you say you want an explanation, but what is there to explain? a saltwater fish won't survive in freshwater, a freshwater fish won't survive in saltwater. all of your other questions depend on what type of crab it is, specificly. there are so many different types of crabs out there that i would have to know the exact species, and even then it would probably be hard to find any information, even on the net. chances are, it won't survive in captivity. as for food, again it depends on the species, but most crabs would feed on small crustations and other dead matter.

i strongly suggest you leave them in their natural habitat, where they are supposed to be.

Answer 3

If they're saltwater crabs, they can only live in saltwater. freshwater will kill them. they can't live in freshwater because they are ocean creatures. brackish water besides being very difficult to maintain will probably kill them too.

Answer 4

I believe you are in NZ?

OK there are several species of crabs you will find locally, some are fully marine and need to live underwater. Others are partly terrestrial and spend a lot of time out of the water, hunting and feeding on rocks between the tide lines.

They are all Marine species though, and need a coldwater marine (rockpool) setup. I would go with 1/2 a tank of water, with some rocks above the surface. Apart from that they are fairly easy to keep, They eat ANYTHING, so it's best not to try keeping anything else in your 'rockpool'. You can feed them sinking fish food pellets, lumps of vege, bits of fish or shrimp.

The reason they wont survive in fresh water is that marine and freshwater fish (and crustaceans) have to regulate their own intermal salinity, and that has to be handled differently in salt and fresh water. A freshwater fish must get rid of fresh water and convserve salt. Some species are able to live in both, but generally it's one or the other.

Ian

Answer 5

they won`t live in fresh water.

Answer 6

You should just go to a pet store and get a crab from there. it'd be simpler and they're really not that expensive. I'm pretty sure they have freshwater crabs or get a hermit crab.

Answer 7

1, 2, and 3 are "no" 4 is maybe. No, they cannot survive in brackish or fresh, AND HERE'S WHY (to answer your question.) They aren't able to breathe correctly in water with a low salinity, and would die. That is like saying, "can a human live in air that is 100% carbon dioxide" lol no that wouldn't work because a human couldn't breathe in that situation neither would crabs. But you never said what kind of crab it was. Is is a hermit crab? Because hermit crabs can live without water (except to drink.) Petsmart sells hermit crabs and freshwater crabs, so look there!