Having trouble identifying this Acro hitchhiking crab
I recently bought a small Acro colony and it had 3 crabs.
<Neat! Evidence of good handling>
I knew there was one in the colony, it's part of why I chose it. But I
didn't expect 3! This album contains the pictures I'm referencing, feel free
to host them on your site though https://imgur.com/a/5b3LK I was able to
identify the small one (3rd & 4th pictures) as a Hairy blue-eyed Acro crab
(Cymo andreossyi) which as I understand it will pick on
<All will/do to extents. I'd keep them all... not that damaging in most
On large colonies they're supposedly symbiotic, but dangerous to small
colonies, so I tossed him in with my P. ciliata mantis shrimp. I was able to
identify the other (last picture) as a Tetralia crab, safe and symbiotic,
and put it in the tank with the coral. But I'm stuck on the one pictured in
the 1st and 3rd pictures. The color matches the coral closely, and the body
shape reminds me of a Trapezia which makes me think that it's commensal.
<I agree on both counts>
It's legs are a little bit fuzzy though. One claw is slightly larger and a
little bit sharper, the other is smaller and has flat tips, clearly intended
for gripping and scraping. I've been Googling for a couple hours now and
haven't been able to get a good ID on him. In the meantime he's in a critter
keeper with an airstone. So, should I put him with the colony
or would it be wiser to let him test his fate with the mantis?
<As stated, I'd keep all>
<And you for sharing. Bob Fenner>