Crab ID required.

LeeG

New Member
Setting up a new aquarium with live rock and the below crab appeared.
Not sure what type it is of if I should keep or remove.
Ive left him in for the moment as the tank is cycling.

crab.jpg
 

Oxylebius

Well-Known Member
It is a type of mithrax crab. The rounded cupped claws provide the ID on this one. The green crab, Mithraculus sculptus, is part of this same family. Not all mithrax crabs are good to have in aquarium - most when small are fine b/c they will pick at algae. All crabs are opportunistic scavengers. Some prefer algae, but when there isn't algae to eat they will go looking for something else to eat.

My opinion - I'd keep it for now, but I'd watch it. If you have a sump, that would be a good location for it to scavenge around for food when it gets a little bigger. Since you are cycling this crab might help to keep some of the algae that you will have growing in check (if it survives the cycling process).
 

LeeG

New Member
Yeah, Id done some of my own googling and thought it was a Mithrax so thanks for confirming.
He's only small at the min but as Ive no sump he will be leaving the tank when the cleanup crew are acquired.
Hes hiding behind a rock currently and providing something for my daughter to watch but he seems to prefer the dark lol

Thanks Oxylebius for the for the id
 

Oxylebius

Well-Known Member
Nocturnal. But, you can get them to come out in the evening with a little coaxing with some food on the tip of a wooden skewer. Crabs can be very interesting critters in tanks. And kids really love them.


My 5 year old nephew loves the hermit crab I have.

 

Tru2nr

Well-Known Member
Kill him! Black claws are usually a bad sign, better to get rid of him now than have him harm fish


Sent from my iPhone using Tapatalk
 

Oxylebius

Well-Known Member
Yes, this hermit is part of my clean up crew. I had him in my previous tank and was then placed in my upgraded tank - I've had him for over 6 years now. He is a great little hermit. Growing on the bigger side, but will remain part of the tank family for years to come. He and my 6 nassarius snails were part of my initial clean up crew back when I initially set up my old 40g breeder in 2009. They are the oldest living critters in my tank.

I also have two coral crabs - a Tetralia crab in one of my acro corals and a Trapezia crab in one of my stylo corals
Oxy's RSM250
and here
Oxy's RSM250

Here are more hermit pics:
Oxy's RSM250
 
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