Crab ID needed (pictures)

raliuha

New member
Hello,
We are building new reef and in one of the rocks we found a crab hitchhiker :bigeyes:
We don't know its ID and we need some info if it's reef safe?

Here are some pictures for identification:





Please, for your help!?
 

raliuha

New member
More stories from our aquarium - we found out another (smaller, approx 1 inch) body of a same, but dead crab this morning. I'm sorry to throw it out without taking photo. Two hours ago one of the starfishes came out from the sand with two wounded legs and we though there is something wrong with the water, because the aquarium is brand new (these are the first inhabitants actually). We have the water for something like 10 days now (with live rocks).

So, you propose to accept that the guy looks like a Sump Crab, huh?

P.S
I just saw him trying to grab the shrimp. Sorry for the silly questions, but we are pure greenhorns. :-(
 

Ohiomom

New member
If the tank is only 10 days old then you really shouldn't have any animals in it..it is TOO SOON. Your tank will go through a cycle and what you have in there may die. Also starfish and shrimp are not the easiest to keep alive in a new tank..I hope it works out well for you but please wait for around 4 weeks maybe longer to add anything.

As for the crab it does look like a gorilla crab and will eventually kill many things in the tank so yes put it in the sump.
 

LeslieH

Premium Member
Lots of people maintain that crabs with blunt tipped claws (which yours has, the first picture shows that very clearly) are harmless algae eaters. That's a reef myth.
 

raliuha

New member
Lots of people maintain that crabs with blunt tipped claws (which yours has, the first picture shows that very clearly) are harmless algae eaters. That's a reef myth.

Excuse me, i want to ensure that i understood you properly (English is not my native language)!
You say that crab is dangerous for the tank?
 

reefmaster3024

New member
I had one of those in my tank from a piece of rock picked up at a local fish store. It was always picking at frags and corals, knocking stuff over and generally it was a pest. I had to break down my whole tank to get it out of there, also I think it was responsible for a couple of gobies deaths
 

LeslieH

Premium Member
Excuse me, i want to ensure that i understood you properly (English is not my native language)!
You say that crab is dangerous for the tank?

What I meant to point out is this: Many reefers have the incorrect belief that the shape of a crab's claws determines if it is good or bad. They believe that blunt-tipped claws mean the crab eats algae and that sharp claws means it is a dangerous predator. This is not true. It doesn't matter what the claws look like - most crabs have the potential to harm other inhabitants of a tank. Only a few filter-feeding and detritus-eating crabs are completely safe.

Your crab appears to be a xanthid crab, maybe in the genus Actaeus. These are well known omnivores that will eat anything. They get more destructive as they get larger. Xanthids are fun to watch & will learn to eat from a stick or even your hand. Let him live in your sump.

Chuck has a great site with many excellent pictures and information on invertebrates that show up in reef tanks. I'm sure it will be an extremely useful tool for you.
http://www.chucksaddiction.com/
 

raliuha

New member
I had one of those in my tank...

What I meant to point out is this...

Thank you for the quick response! I knew this forum is the right place for us. :beer:
I will do my best to catch the hairy dude tonight. After some research the decision to go with some trap solution in order to take him out. Let's hope it won't be difficult.
I promise better pictures from the sump. :p
 

kyrin01

New member
Before u put it in the sump put it in a small glass bowl and take a close up picture. THEN put it in the sump.
 

raliuha

New member
Mission accomplished. :fun2:

4147353559_469f6d15ca_o.jpg


I will post hunt log later. Just for the record - Coca Cola bottle (500ml) with raw shrimp inside works just fine as a trap.
 

Seilethin

New member
Good job, I've seen people spend weeks trying to catch a stray crab in their tank. Also, that is a wonderful picture, I'm sure someone will be able to give you a positive ID very soon.
Again, good job, and good luck with your tank!
 

Bongo Shrimp

P. ceratophthalma
Good thing you got that out! Seeing it up close in detail like that, I can tell it would have been no good to keep in the tank.
 

Sugar Magnolia

Mother of Dachshunds
Staff member
RC Mod
Mission accomplished. :fun2:

4147353559_469f6d15ca_o.jpg


I will post hunt log later. Just for the record - Coca Cola bottle (500ml) with raw shrimp inside works just fine as a trap.

Wow! That's a fantastic picture! Good catch. I have a roguer xanthid in my tank that I haven't been able to catch. I'll try the bottle! ;)
 

raliuha

New member
Actually the bottle is not so important, the benefit from it is that is plastic and you can fit it better in the desired space because it's soft (we've tried with glass, but the only benefit was the dinner for the shrimp). :)
The most important part is the bait, it was smelling so strong that the poor Sump guy was not able to resist at all. It took something like 10 minutes to catch him, with all the lights on.
However, I've created short animation to fulfill my promise about the log. :frog:

animd.gif


P.S.
Do not mention the aiptasia in the upper-right, when the tank becomes stable, we will take care of them... somehow. :blown:
 
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LeslieH

Premium Member
Hi Raliuha -- Great photos, thanks! From looking at these I think the crab isn't a xanthid at all but is closer to a mithracid. Emerald crabs belong to this group but even they can become problems. Glad to know that you were able to capture it.
 

Zire

New member
That was an awesome little clip show. It almost seems to me that in the final shot the crab looks up and realizes he's been caught. Congratulations.
 
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