Hibernating fiddler crabs?

[Paul E. Morphius]

More help needed on crabs! This time, the odd-looking fiddler crab.

I have a pair of male fiddler crabs. Once refuses to leave its burrow (let's call him Crab-A to avoid confusion =P), the other refuses do build his own (Crab-B). The Crab-B either tries to steal Crab-A's burrow or just basks by the water pool. Winter is coming this time around so I guess it is reasonable to assume the Crab-A's hibernating (I'm pretty sure he's alive) but Crab-B is acting quite the opposite. He seems to enjoy the cold water. 0.o

Any help on the odd couple's strange behavior would be much appreciated. ^^

 

[Paul E. Morphius]

Here are Crab-B's attempts to evict Crab-A's from his own home.

 

[Paul E. Morphius]

Crab-B enjoying the cold water. Seriously... he couldn't be short on land.

 

[BigJim]

Are these crabs from warmer regions? You may need to provide a heater. Look for the mat heaters that adhere to the bottom glass outside the tank. They sell them for reptile terrariums, but I think they would work nicely in your case.

 

[adeebm]

Nice looking fiddlers! Yeah, most fiddlers come from warmer regions, I would keep the temp between 70F to 85F. I doubt any crabs hibernate, but their activity levels would decrease when it's colder(which is not a good thing). You seem to have a very small land section, which is probably why the males are fighting. They will need more space to each have their own burrows. Also, fiddlers should be kept at atleast a 1:2 male to female ratio to reduce aggression. Under tank heaters like BigJim said, are a good idea. You could also use heat bulbs.

PS. You get some sweet looking crabs over there, any chance you could mail me some?

--Adeeb

 

[Paul E. Morphius]

@Big Jim - Unfortunately, Crab-B has died just recently. Must have been the cold. Pity I didn't get to deal with the problem when I could have. I should get a heat pad immediately and deeper sand perhaps.

@Adeebm - I actually provided the two fiddlers with two equally-sized "islands" with a shallow water barrier. Would that have been enough? The Crab-B kept insisting on invading Crab-A's island while Crab-A was just minding his own business.

These crabs are actually native to Hong Kong so I guess I wouldn't call it a tropical specie. It gets real cold during winter... but no snow.

They look pretty sweet, don't they? =P Perhaps I can mail you some! Trade ya for an RCC? >.O

 

[adeebm]

How big is your tank and land area(s)? For the temp, you also have to remember that if these crabs are burrowing and spending time in the ocean in the wild, chances are they experience a higher temp at winter than the ambient air temp. So I would keep the temp up anyway.

Shipping to/from Hong Kong to US probably costs a fortune I'm trying to get my LFS to order some indonesian fids for me...

--Adeeb

 

[Paul E. Morphius]

40% land and the rest water. Only realized my mistake now. =/ Should it be 90% land and 10 percent water?

Oh I didn't realize that. =P Good luck with your fiddlers!

 

[adeebm]

no, 40% land is good, your tank may just be too small. Dimensions? Oh, and my crab tank was getting chilly too, so I just got an infrared heat bulb(for reptiles). It works great, raises ambient temps by 6-8F. You could try that for heat.

I think 2-5 day shipping is about $75, but that's still cheaper than buying from an importer. Maybe I could trade you some RCCs and local fids for the ones you get there

--Adeeb

 

[Paul E. Morphius]

The dimentions are 33 cm x 21cm x 19cm. Same with my unidentified mangrove crab.

Speaking of heat lamps, would I need one for the mangrove crab too? He seems to do fine without it, but I don't exactly know how a "fine crab" is.

It's very costly to ship from here to the states. Also the issue that it isn't a native specie there. Red claw crabs can be found here though. Just don't know where to look. =P I'll see what I can do. >.0

 

[adeebm]

That tank might be too small for 2 male fiddlers. They need enough land to walk around and burrow. You should consider moving them to a 10gal tank.

Your mangrove crab might need heating too. How cold is it? Mine act normal when they are cold, just slower.

Yeah, shipping is a pain. And customs would probably burn it

--Adeeb

 

[Paul E. Morphius]

Isn't 33cm x 21cm x 19cm more than 10 gallons?

Outside the aquarium, it is about 20 degrees celsius so I can imagine it is below that temperature in the tank.

Burn 'em? Literally? 0.o

Oh and one more question. =P Would a study light do as an alternative heat source?

 

[adeebm]

Your tank is 3.5 gallons. A ten gallon's dimensions are 50cm x 27cm x 33cm.
Standard Tank Sizes

I don't think a study light would do it, it's not meant for heat. Plus it would get cold in the night when you turn it off.

--Adeeb

 

[Paul E. Morphius]

Ah I see. I'll stick to the heat pad then. =P

Thanks for answering my questions, Adeeb. ^^

 

[Paul E. Morphius]

Just bought a heat pad two days ago, and a pair of aquarium filters for my freshwater shrimp and my alien mangrove crab.

The following day after the heat pad's installation, it began to show results! The fiddler (Apparently the type of fiddler I have is called a "watermelon crab". May be useful to those who are interested in keeping one of these little critters =P) left it's burrow and appeared to hug the heat pad with its claws as if it said "Oh some heat at last!" (Don't worry. The heat pad was installed outside of the wall of the tank). The day after that, he finally started eating the food I have left out for over a week (even the mould that grew on it). He also scuttles back to his burrow when I come too close which I assume is perfectly normal for a healthy crab.

For those who have come to answer my questions, thank you so much! I don't think the crab would have survived without your help. =]

 

[BigJim]

Glad to hear your critters are doing better.