And YES, land hermit crabs can go underwaterwithout drowning. In fact, they NEED water that they cansubmerge in to do well in captivity for several reasons. Theonly way they drown usually is if there is no escape route. I HAVENEVER HAD A CRAB DROWN IN THE 3 YEARS I HAVE HAD DEEPPOOLS.
Measure Shell Openings
It is important to choose shells with thecorrect opening size for your hermit crabs.The opening size you choose should be 1/8" bigger than yourhermit crab's big claw. You should measure the lengthof the largest claw, not how wide it is.If your hermit crab dies, it will begin todecompose – and its carcass will begin to smell putrid. Ifyou can't smell anything, pick the crab out of the tank toget a closer whiff. If you smell a salty, rotten scent, there's agood chance that your crab has passed away. Assume that yourcrab is molting.
For a 10 gallon tank that may be 10 tinycrabs, 6 small crabs or 4 medium crabs or areasonable combination of the above. You can keep hermitcrabs of different sizes together as long as your substratedepth accommodates your largest crab being able tocompletely bury when he needs to molt.
If you just have to know then there issome thought that the female land hermit crab hastiny genital openings called gonopores. Gonopores are located onthe first segment on the back pair of walking legs. They are nearthe joint of the cephalothorax and abdomen very close to the body.Only to female crab has them.
When a hermit crab is out of itsshell—either because of a molt or anotherenvironmental cause—it's stressed and vulnerable. Yourcrab needs protection from the other crabs in thehabitat, as well as a little coaxing so that it will return to itsshell. The molting cycle can take up to one month, so bepatient.
Most healthy crabs molt at least once every 18months. SOMETIMES smaller crabs molt more frequently, butnot always. So don't worry if it's been a year and your crabhasn't molted yet. Just continue to take good care of it,and the crab will molt when it istime.
Is it normal for hermit crabs to stayburied over the long periods of time? Your crabs mayalso be burying themselves due to lack of humidity in thetank. They try to dig to get to where the substrate/sand isthe dampest because even though they are land crabs,they have gills and require moisture to breathe.
Do not disturb a crab that is limply hanging outof their shell, but rather, protect them from othercrabs. If they are molting, they should continue through theprocess if given the time to do so. If they have died, theywill start to smell badly within a few days.
Hermit crabs have soft, exposed abdomens. Thisleaves them vulnerable to predators. To protect themselves,hermit crabs search for abandoned shells —usually sea snail shells. When they find one that fits, theytuck themselves inside it for protection and carry it with themwherever they go.
Misting the tank and substrate increases the humidityinstantly, while additional damp sponges help maintain it.Additional heat can be supplied with a heat bulb (nota heat lamp for reptiles, which is dangerous for hermitcrabs) or a heat mat underneath one side of thetank.
