Bug Identification

[seven881]

All little background info
I recently lost some open brain corals and I found that they were receding from the bottom where it touches the sand then slowly moving up. Some of my acans were also starting to recede. I checked the water parameters and the ALK, MG, CA Salinity all appeared to be fine and these corals had been in the tank for at least 4 months without showing any signs of stress and one acan was showing growth with new mouths. I spoke with my LFS and he stated it's probably not a chemistry issue, but more than likely a worm or bug eating the LPS.
<O</O<O
Not so pleasant discovery
I was looking at my dead wellsophyllia and discovered a bug that looks like a scorpion. The bug was in the circle hole in the middle of the wellsophyllia. The head is hard like a shrimp or lobster and the back end is soft. I looked through some old pictures of the coral and he appeared to have been there all along. I'm assuming this creature was eating the LPS, but I have no idea what it is nor did my reefer buddies. Does anyone know what it could be and could it be eating the LPS?

<O</O

 

[Bongo Shrimp]

I believe this is it. From the family CALLIANASSIDAE:
http://www.poppe-images.com/?t=17&photoid=969784

 

[dc]

[moved]...

 

[LeslieH]

The extended egg sac looks like the abdomen of a callianassid but it's not Bongo. It's really a female gall crab, family Cryptochiridae. The females & sometimes the males live in cavities or galls on corals. Often the males are free-living and scurry around the corals looking for females. Normally that sac would be so full of eggs she would be barely able to move. They do not really hurt the corals - especially the females that can't get out and are restricted to filter feeding, eating mucus or the tissue directly around the cavity, or algae. Something else is responsible for the tissue loss, especially since it started from the base.

Here's a pic of the similar species Utinomiella cf dimorpha - http://www.flickr.com/photos/artour_a/4289256556/

 

[Bongo Shrimp]

Sorry I didn't take a shrimp identification class.

 

[LeslieH]

That, and 30+ years spent just looking at inverts. :spin2: On the other hand, I don't have tanks or much of a life either! :lol:

 

[pagojoe]

Don't let her trick ya, Leslie gets to do ALL KINDS of fun stuff

 

[seven881]

Thanks for the help! I'll keep looking for the cause of the tissue loss.

 

[mscarpena]

I had a gall crab(or what I believed to be one) in my elegance coral and it's health was going down hill quickly. I saw the crab one day and removed it. The coral immediately started to turn around and still looks great to this day. Now Leslie knows a a lot more than I do on these critters, but it may have cause and infection or some sort of irritation in this case. Who knows. Or maybe mine was not really a gall crab after all, but sure looked like it.

 

[LeslieH]

Leslie has had a very heavy chain connecting her to her office for several years. She has not gotten to do any fun stuff in far too long..... :sad1:

Hey, Mark, when it comes to life in tanks you guys with experience know more than I do. I can id stuff, I know the natural history in general, seen them in the wild, & have lots of books. The thing is, inverts & fish don't read so they don't know what they're supposed to do. What happens in the artificial set-up of a reef tank is different than life in the ocean. So if you observed that your coral did better without the crab - and it really was a gall crab - that's a valuable piece of information for Seven881 & everyone else. More useful too!

 

[LeslieH]

Hmmm.... just the fact that it was beautiful makes me think that it wasn't a gall crab. They're mostly dull tan or brown and kinda homely looking. The 3 crabs at the bottom of the link are 2 swimming crabs (Portunidae) and 1 spider (Majidae). All 3 are voracious predators on anything they can get their greedy claws on.

 

[mscarpena]

http://www.google.com/imgres?imgurl...org.mozilla:en-US:official&ndsp=18&tbs=isch:1

There is a picture of a crab at the bottom of this page and that is exactly what it looked like(except color). It was bright purple, orange, and white. Absolutely beautiful. It was nestled down in the elegance coral and it was eating the flesh of the coral. I removed it and it turned around and started looking better the next day.

 

[seven881]

I moved the acans onto a frag rack and noticed that there were pods running all over them. I dipped both acans in revive and about 30-40 pods were in the container. Not sure if they were eating the dead or live flesh, but they seem to be doing better after the dip.