Acro Crab or Pest?

[socalmonty]

Just finished acclimating an acro colony from Live Aquaria and found this little guy in the bottom of the container. He has a band across his face like the acro crabs I have read about but he's not white. He is smooth not hairy. Friend or foe?

 

[Allmost]

Good guy. Put him by the same colony, although they do go from one to other.

 

[socalmonty]

Good guy. Put him by the same colony, although they do go from one to other.

Thanks, Allmost. I had someone on the SoCal forum tell me he was a bad guy because he has black on the tops of his claws. Does that make any sense to you?

 

[Arkayology]

Looks just like my acropora crab. All it does is sit in my poccilapora colony all day. The coral had great PE and doesn't mind at all.

 

[dzhuo]

He has a band across his face like the acro crabs I have read about but he's not white.

A lot of acro crabs are not white.

I had someone on the SoCal forum tell me he was a bad guy because he has black on the tops of his claws. Does that make any sense to you?

No. That doesn't make sense at all. What you have is a Trapezia digitalis which is safe to keep.

 

[defchild84]

Sorry to hijack , but I have been curious - I would love to have a few in my colonies, but vaguely recall a thread where someone had stated that attaching a acropora crab into a aquacultured colony, could irritate it badly, even to the death of the colony? Makes sense, but... just would like a little more confirmation from other's experience. I have always wanted these little guys, but .... just gotta solve this question lol

 

[socalmonty]

Thanks, everyone. Just dropped the little guy into his acro. Looking forward to having him in the tank.

 

[dzhuo]

vaguely recall a thread where someone had stated that attaching a acropora crab into a aquacultured colony, could irritate it badly, even to the death of the colony?

When the crab is initially settled to the colony, the host (the coral) will be slightly irritated and grow will slow a bit. The long term relationship, however, is very positive for both the crab and the host. If the host colony is small (I don't know the exact colony per crab size data so I can't say for sure) or not healthy, the crab will die faster than the coral. If you have a mature and healthy colony, I would encourage you to try one. The problem is finding the right carb. For example, majority of all acro crabs LiveAquaria sells are Trapezia which prefer Pocillopora or Seriatopora as host. The more desirable ones are Tetralia which gives you more options of finding an acro host. Unfortunately, I have never seen Tetralia for sell and people who have them aren't likely to give them up.