Help us build a bitchin' crabitat!
September 11, 2014 11:59 AM   Subscribe

My parents picked up a hermit crab for my son in Florida and now that we've got him (her?) home, I'm wondering what we need to PROPERLY take care of our new friend, Matt (yes, that is what my son named him).

Initially my son felt horrible for this sad little crab and wanted to hop on a plane and fly him back to Florida, releasing him so he could return to his family, but that's not an option. Now that we've got this fella and I've done some quick research I'm realizing it's gonna take us buying some things and amending his crabitat to keep him happy.

Right now he's in his small plastic box with very little colored rock, an extra shell, a plastic palm tree, and a wet sponge. This will not do. He seems to have fared well on the trip (a two day, 16 hour car ride!) and he seems quite rambunctious, scrambling around a lot and eating fine, but I'd like to get him a home that will make him happier.

I know we need a new dwelling. How big? What kind of substrate should we buy so that he can burrow (specific recommendations would be great!). Does he need more things to climb? And what should we buy to feed this guy? I read we need saltwater and freshwater for him -- where does one procure saltwater?!

Most importantly, is there one place online where we can buy all the things we need?
posted by youandiandaflame to Pets & Animals (6 answers total) 9 users marked this as a favorite
Please, please don't go by what chain pet stores say - they will sell you bad things! PetSmart is awful for pet care.

This is a good forum post for crab basics. There's more excellent info further down the thread, and I highly recommend reading it.

Re: saltwater - find your local independent aquarium store and ask them how to make it properly; they will happily sell you the salt. (Yes, I'm sure one could do it at home armed with internet instructions, but isn't it easier to start off with help?)
posted by Nyx at 12:19 PM on September 11, 2014 [1 favorite]

Here's another good forum:

The basics: Humidity and heat are essential!

Sand should be sand-castle consistency (damp) and deep enough so that crabs can bury themselves to molt (they may disappear for weeks at a time, particularly after they've just been brought home from pet store--unless you smell a fishy smell, they are fine and should remain buried)

Hermit crabs are highly social, and your crab would benefit from a friend.

They like having lots of room to roam.

They will eat almost anything humans can. Safe/unsafe food list:

I make saltwater for my crabs using instant ocean:
I guess the stuff sold specifically for hermit crabs isn't the greatest (same thing with commercial hermit crab food mixes).

I'm in a rush, but please MeMail me with any questions!
posted by whistle pig at 1:11 PM on September 11, 2014 [2 favorites]

I must insist you purchase one of these humiliating shells for your crustacean pal.
posted by Kafkaesque at 1:34 PM on September 11, 2014 [2 favorites]

yes - more than one crab is needed. they are very social creatures. please buy a friend for Matt.
posted by harrietthespy at 2:08 PM on September 11, 2014

I keep a half dozen hermit crabs in a 10 gallon aquarium. They have been in there for over a dozen years w/o any casualties, so things are going well.

a) substrate: I use sand sold specifically for kids sandboxes, well rinsed (it's quite dusty out of the bag). A rather large bag of it cost under $5 at my local hardware store. Hermit crabs like to dig so my sand layer is 4-6" deep, also the availability of deep sand is important for molting. Keep substrate moist--about the same consistency that you would need to build a sand castle--with decholorinated fresh water and groomed in to a slope. The slope is so the crabs can choose their own preference of wet vs dry sand (the sand on the higher end of the slope is dryer, of course). On the shallow end of the slope, I drop in some wetted coconut fibers (the brick linked is like a 5 year supply) on top of the sand because the crabs like to tunnel around in it.

b) More things to climb are great. Some folks make rope hammocks for their crabs, they also will climb branches. Mopani, grapevine and cholla are all good for the crabitat: make sure you buy it from a pet store to avoid getting wood treated with perservatives. I use a coco fiber mat as a backing on the inside of the tank and the smaller crabs are always clinging to keep. Be aware that crabs are stronger than they look and if the tank's lid isn't tightly attached, crabs that can reach the top will try to climb all the way out.

c) My crabs eat the trimmings of whatever we use as dinner ingredients (fresh veggies and fruit, tiny shreds of cheese, raw nuts) as well as bits of hardboiled egg and cooked shrimp shells, meat, and brown rice. I do not feed them commercial fish or hermit crab food as they almost always include preservatives that are harmful to crabs. Feed Matt in the evening and remove the uneaten bits in the morning. The crab(s) will have dragged bits of food all over the enclosure so I find using a pair of chopsticks the best way to pluck stray bits out of the tank.

d) Both fresh and salt water should be provided: I have two shallow bowls set out for the crabs, one for each type of water. The bowls should be shallow enough (or have ramps) for the crab to climb back out on his own, terrestrial hermit crabs can drown. Treat all water used in the crabitat, including water used to rinse the substrate, with a conditioner intended for aquatic life: most muni water supplies now add chloramine to tap water, chloramine does not evaporate out of standing water like chlorine does. Change the water daily if you can, it tends to quickly foul with bits of food and droppings.

e) Hermit crabs poop. There are tiny litter scoopers for them at the pet store. Scoop daily.

f) Get an assortment of shells for Matt to change into, they often like to swap shells from day to day. In particular, I've noticed hermit crabs who are recent arrivals from pet stores change shells almost immediately, I suspect it's because they've been stuck in an unsatisfactory shell but there weren't any other choices available. Crabs can be surprisingly picky about the type of shell they like (I have a big one who only likes turbos but at the size of a human fist, I can no longer find big enough turbo shells for him to move up into so he's going to have to suck it up and switch to a new kind of shell on his next molt) so take a good look at the shell he is in now and try to find more in the same size and up. I buy all my crab shells on ebay.

g) The temperature and humidity of the enclosure are super important; they cannot survive in an unheated and/or dry tank. Additionally, the range of temperature and humidity they find comfortable is rather narrow. Get a combo thermo/hydrometer gauge so you know for sure you are in the right range.

h) They are very social critters, get a few more crabs as friends. They click and chitter at each other, it's pretty neat.
posted by jamaro at 2:40 PM on September 11, 2014 [22 favorites]

I just wanted to highlight this:

Get an assortment of shells for Matt to change into, they often like to swap shells from day to day.

To grow in a healthy way, you really need to get a variety of shells in different shapes and sizes until you begin to see a pattern as to which shape Matt likes the best. You should have at least half a dozen or so in his(her) tank. I get all my shells here
posted by Shouraku at 3:15 PM on October 8, 2014

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