Crab identification please?

[Jalo]

Can anyone please help in identifying this crab? Is it safe in a reef tank and will it cause any harm on fishes and snails? I can't find anything in the internet that looks the same as this one, we have two in the aquarium at the moment.

Thank you in advance!

 

[Tripod1404]

How large is it and how are the tips of the claws shaped? If they are sharp, it is likely a predator, of they are "spoon" tipped, it likely a herbivore. A picture from the front might help.

 

[Jalo]

They eat seaweed flakes, dead fish (a small pj cardinal died because it was not eating), and carnivore pellets.

About the size, this one with black spots on its legs is about 2 inches, the smaller crab that got yellow spots on legs is 1 1/2 inches. They tend to swim around the aquarium too, I'm worried that they might be trying to catch the fishes.

 

[Jalo]

Here's a picture of the smaller crab.

 

[Tripod1404]

They are nice looking crabs, but I dont really know what they are. Their legs show they are swimming crabs and all crabs will scavenge a dead fish. But I dont know it it will hunt a crab or not.

 

[Jalo]

Okay, thank you! I'll continue to monitor them just to be sure then

 

[Rover88]

It /kinda/ looks like a flower moon crab?

I may have spent some hours today poring over pictures of crabs to find something similar!

 

[Rover88]

Specifically, Matuta planipes.

http://3.bp.blogspot.com/-rb56stcC1QA/U-Sm2WYco4I/AAAAAAAAMSE/nKlsZzZGgH8/s1600/matutidae.jpg

 

[Jalo]

Wow, yes they do look like flower moon crab! I love the name tbh hahaha

 

[Rover88]

If its not one of those, its likely something from a very similar species. You can see them better to make comparisons.

 

[Coralfuture]

They look really cool

 

[Tripod1404]

From the what people wrote about moon crabs in other forums, they seem to be reef safe. But a crab big and hungry enough will kill a fish, if it can subdue it. Even emerald crabs can sometimes kill small fish. But I think, as long as they are well fed and not kept with fish very small, they are safe.

Although in nature they seem to be sea grass specie. So if you have a display fuge with sandy bottom, they will be very good and interesting additions.

 

[Jalo]

Okay, thank you!