My blog has moved!

You should be automatically redirected in 5 seconds. If not, visit
and update your bookmarks.

Tuesday, January 29, 2008

Hitchhikers... Very Cool!

So, I bought a very large pink birdsnest a couple weeks back.  The thing is the size of my fist, though the bottom 1/3 is most likely dead and the top is a little bleached, it has decent polyp extension.  Well, the second day I had it, I thought I noticed something moving within the branches when the lights went off.  The next day, I saw it again and sure enough, I found 2 hitchhikers.  acro crab

The first is an acro crab.  Acro crabs are harmless commensals, apparently living in harmony with their associated coral.  It is unknown what they feed on, but presumably the mucus secreted by the coral or perhaps particles trapped by the coral polyps.

The second was either a pistol shrimp or a small lobster.  The jury Pistol Shrimpis still out, but I am leaning towards a pistol shrimp.  turns out it may be commensal as well, but I was concerned, so I moved him to the fuge for now.  I have not seen him since, but I think he is still in there.  He was very very small.


a fellow aquarist said...

Hi Derek, did you ever figure out if your hitchhiker was a pistol shrimp or a baby lobster? I have a hitchhiker that looks just like it: small red-brown, and one claw is slightly larger than the other. He hides under the edge of a rock, throwing the sand and bits of shell out in front of him like he's making a burrow. If a hermit crab gets near his front door, he becomes very territorial and want to fight (eat?) the crab. I can't seem to find any good ID pix on the web with which to compare him.

Derek M. Rodner said...

In my case, it was definitely a reef lobster, but he disappeared (died?) in my sump before I could see him work. Sounds like yours might be the same.

Listen to your tank at night. Do you hear any clicking sounds at all? If you do, then it is a pistol shrimp.