It started a couple of weeks ago when I saw an ad in the local classifieds, a girl going off to college was trying to rehome her two crabs and equipment. I thought I had made arrangements to adopt her crabs, then she disappeared. In the meantime I was doing a lot of research on keeping hermit crabs and I decided I wanted some anyway. I have spare 10 gallon tanks, so decided to use one of those if I found crabs before I found a bigger terrarium. I used to keep crested geckos, which have similar high humidity requirements as hermit crabs. I have plenty of decor and equipment left from the geckos. Unfortunately I sold their big Exo Terra tanks.
Next, I checked with several pet stores in my area that normally carry hermit crabs, but all of them were out of them. Then yesterday I went to a reptile expo where they sell a variety of equipment and animals for good prices. Finally I found someone who was selling hermit crabs. Typically, they didn't seem to know much about them, most were in painted shells and they were kept in a big, open plastic tub with about an inch of dry sand in the bottom. I asked "what kind of crabs are these?" and the answer was "I didn't know they came in kinds, I'll ask my husband" and his answer was "Haiti, they're from Haiti".
I'm pretty sure they're PP's, they were all varying shades of red with purple pincers. Anyway, I bought three of the larger ones, with clean shells. The biggest one is in a long shell with a few spikes. I figured if they're bigger they might have a better chance of surviving the stress of being relocated. Two are about the size of a golf ball, the third is about 1.5 times that size. So right now they're all in a 10 gallon tank, this is temporary until I get a bigger tank. Which leads my to my first question - is it better for them to be in a standard aquarium or an Exo Terra style terrarium with doors? If I get a standard tank, is 20 gal a good size for 3 crabs or do they need more? I have plenty of empty small acrylic and glass tanks (2.5 - 5 gal) which might make a topper when I get a bigger tank.
The 10 gal tank has a screen top which I've covered in plastic wrap (except for a space where the "lid" of the screen top opens). They've got a fresh water dish and a salt water dish. My apartment is well air conditioned, so I set up a bubbler in the freshwater dish, it's a bit foamy now. I use Seachem Prime as a dechlorinator, and Coralife marine/reef salt. I used dechlorinated salt water to moisten their substrate, which is mostly play sand with some eco-earth to hold moisture. The tank is about half full with substrate, which is more than three times the height of the biggest crab/shell. I've attached a UTH to the back side of the tank, above the substrate. I've put in a bit of decor that will allow them to climb or hide, but I didn't want to overcrowd the tank. Salt water question: I usually use a refractometer to measure salinity, does anyone know what specific gravity (s.g.) salt water for hermit crabs should be? Is it always the same, whether in their salt water dish or their substrate?
For food, last night I gave them a flat reptile dish with fresh chopped organic blueberries, pieces of salt free whole grain crackers, and smelly shrimp bottom feeder fish pellets with a couple of drops of water to soften them. I know it's hard to tell if they've been eating. I'm planning to toss everything this evening and give them different items from the food list here. I have glow in the dark reptile dishes, would those help them find food or do they mainly find it by smell? Are there any "irresistible" foods that they really like? I'm thinking of chopping up a raw tiger shrimp, is it better to give it to them with shell on or peeled? I've also read that they will eat eggs, is it best to give them raw or cooked? I assume you'd give them with shells. I have button quail which lay small, edible eggs which I think they'd like.
The glow in the dark dish shouldn't be necessary, they will find the food. I do think it is mostly based on scent as they have compound eyes, and thus don't see clear images as much as they sense movement/ shadows, etc. Some say they do see uv, even in more colors than we do, so maybe they could see the dish? Since they are nocturnal though, I doubt the light up dish has much effect. For what it's worth, I always feel like when I have introduced crabs to my colony they have taken a while to really start eating. Just experiment and you will start to figure out their likes and dislikes.
