purple crab?

[Mihai]

Any idea what's up with this guy? Looks ferocious to me but I have a
goby that eluded him for three months... Do you know if it gets big?
How big? He already rules my 20 gal refugium...

He's a hitchhiker from the NC coast (was smaller than a thumbnail
when he came).

Thanks,
Mihai

 

[garagebrian]

I don't know what it is, but looks great! What does it eat?

 

[Mihai]

Meaty stuff - it's not picky (fish pieces, shrimp pieces, mysis, Formula frozen, etc.). I also see it often sifting the sand in the refugium and from time to time moving really fast as if it feels something in. I never saw it catching anything from the sand, but it caught a few bristle worms that I had in the tank and ate them.

Regards,
Mihai

 

[Fatal Morgana]

Time bomb. I will keep it in my tank with no fish.

 

[SnowManSnow]

Personally, I'd pull the guy out The joy of seeing him probably isnt equal to the investment you have in your other inhabitants.

Just my 2 cents

 

[garagebrian]

I guess each to his own, but he looks cool! Since he is in the refugium I don't see him doing too much damage if there is nothing else in there? Unless he is eating your pods? I love that first picture, great macro shot! What camera are you using?

 

[Mihai]

Thanks, I have a Canon G3, not a great camera, but it's OK. I don't have much of anything in the refugium except for algae (he doesn't touch them) and some hitchickers - snails, stars, a few other crabs and a goby. I'm somewhat worried about the goby (although in the wild they likely were sharing the same algae when they were little) and potentially about other crabs (I also have two decorator crabs - I found one 3 weeks after I got the stuff home and another one 2.5 monhts after that - they are super-good at hiding!!!).

I'll try to see if it eats anything else. Soon (maybe a month?) I'll have a large (60gal) sump available for it if it doesn't behave.

garagebrian, what's that a grow out tank? If you read RC's last month issue you'll see that they strongly recommend against using the quarantine tank for anything else but quarantine...

Regards,
M.

 

[garagebrian]

Hey M,

Boy, I forgot to update my signature. Originally it was going to be 3 tanks, 75, 20-55(the grow-out tank) and a 8-10 gallon quarantine. I have since scaled back my plans to a 75 gal reef with sump and a 5-10 gallon quarantine tank that will remain empty most of the time(except it will be busy the first few months as I plan on quarantining all corals at least 2 weeks and all fish at least 4).

B.

I have included a link to my web page that will be documenting my 75 and all my other projects.

 

[Anonymous]

It looks like a small stone crab to me. If it is they eat snails, crabs, shrimp, etc. When larger they can even crack and eat shellfish. Nice addition. Andy

 

[ricky1414]

Aren't stone crabs a colder water species?

 

[Anonymous]

There are many types. The poster said it came from NC, I am on the SC coast and find them all the time. Some are called stone some mud, etc. I am not sure if it is a stone crab or not. The local s/c here are rather mellow. Andy

 

[Mihai]

It looks like a small stone crab to me. If it is they eat snails, crabs, shrimp, etc. When larger they can even crack and eat shellfish. Nice addition. Andy

The only suspected victim so far is a nassarius snail (and the mentioned brissle worm), let's hope he sticks to that.

The decorator crab is almost double in size so it should be fine.
Mihai

 

[Mihai]

I spoke too soon. Like it would have seen what I just said this afternoon, this evening the purple crab attacked the decorator crab (that is twice the size of the purple crab, as I said). It broke two of its legs and almost broke two others before I managed to save him (and move him in the main tank).

I want to get everybody else out of there, especially the goby, but I only glimpse this guy once a week at the best: catching it is out of question!

I'll try to expedite the sump construction so I can move the purple crab there.

BTW, after some research I found out that the purple crab can get larger than my fist and take out a finger when it's that size...

Regards,
Mihai

 

[Anonymous]

Hey Mihai, I have been thinking about this crab. It's pincers seem to be the same size. Adult s/c have pincers of unequal size. Perhaps it could be a porcelain crab. There are a couple of p crabs in the Carolinas. Most are on the west coast though. They stay much smaller than the stone/mud crabs. These crabs have pincers of the same size. The stone crabs here in Charleston get very big. They dig down in the sand under the jetties and wait out the tide. Some are of sim. color as yours maybe more lavender-gray. When disturbed they try very hard not to move, trying to act like a rock! Good luck with it. Andy

 

[Juck]

Damn that's a scary looking crab. Those claws are made for killing stuff,,, not picking algae.

 

[garagebrian]

From what I understand most porcelin crabs are filter feeders, so I don't think this guy would be one. Especially after the decorator crab incident. But I could be wrong

 

[Anonymous]

Quickest way to ID a porcelain crab is to count the # of legs. Porcelain's have their last two walking legs hidden and tucked under their body, so it appears they only have 3 sets of walking legs. The crab in the pic is not a porcelain. But I don't know what it is.

 

[Fatal Morgana]

That's not a porcelain crab or any of the filter feeders. They and their relatives never have such a pair of aggressive claws typical of predatory decapods.

 

[Anonymous]

There are porcelain crabs with huge pincers. Like I said in other post, most are on west coast. In SC we have a couple of porcelains with fat claws with 5TH pair walking legs folded. I assume these same crabs could be on the coast of NC as well. I still bet on stone crab though. Andy
Look at the pic of a FAT CLAWED Porcelain crab
http://www.enature.com/fieldguide/showS ... num=SC0033

 

[Anonymous]

5th pair? wow that's a new discovery in crab anatomy then, isn't it?