The Bone Yard

[GuySmilie]

Greetings!
I've been letting my new tank mature for the past six months before introducing any advanced livestock. And now I am experiencing a few fatalities. When I started this tank I included 2 blue-green chromis, 1 cleaner shrimp, 2 clowns, a BIG black brittle star, and various snails, etc. No additional livestock since the beginning.

Monday, I found two tentacles that had been removed from the star.
Wednesday, I found the shrimp had been gutted. The head and body meat were still intact.
And now this evening one of the clowns is AWOL. He was there this morning.

Since there is always a desk lamp on in the room where the tank is, it never gets totally dark in there. So I never see any predators out and about.

But when I first added the live rock 6 months back, I did catch a glimpse of a green crab, about the size of your thumbnail, who stuck his face out from one of the many crevices. Haven't seen him since.

I never see the brittle star in motion, but I do see his tentacles from beneath and between the rocks during the daytime.

I've never kept black brittle stars before, so I'm not all that familiar with them. Can these bigger ones take out shrimp and clownfish? I always heard that they were way less aggressive scavengers.

 

[chrismunn]

i had a nuisance crab one time, he came with a piece of rock. the only thing he ever did wrong was eat my montipora. after that i exterminated him.

 

[pondy]

what about a mantis shrimp? I hear they do the same thing

 

[chrismhaase]

look at night with a flash light. Try feeding the tank an hour or to after the lights go out.

 

[coralnut99]

All nocturnal crabs are opportunistic omnivores. Basically means they'll eat anything that's available. I had one devour about $40 worth of astreas before I nailed him.

 

[GuySmilie]

Well, if I do indeed have a killer lurking in there, I wonder why it's taken her six months to go on a rampage?

 

[humbugy]

to get big enough to do some damage

 

[coralnut99]

<a href=showthread.php?s=&postid=11310258#post11310258 target=_blank>Originally posted</a> by humbugy
to get big enough to do some damage

Absolutely correct. It's probably taken several molts for it to get up to size. And it's probably not done growing, though it's tough to judge. Most any coral we acquire has the potential for harboring a miniscule hitch-hiker crab of some sort.

 

[GuySmilie]

I finally caught the little turd tonight!
Now he's a sump dweller.

 

[jdieck]

<a href=showthread.php?s=&postid=11431053#post11431053 target=_blank>Originally posted</a> by GuySmilie
I finally caught the little turd tonight!
Now he's a sump dweller.

Was it the crab?
If the problem continue I would blame either a manthis or the brittle star.

 

[GuySmilie]

The brittle star finally lost most of her tentacles so I moved her to QT but she didn't survive too long. The crab I caught tonight stuck his face out at me in full light (I think he's probably hungry now that I've removed his brittle star snack). Anyway, the crab just happened to be on one of my smaller rocks. So I yanked the rock and put it in another bucket of rubble that I keep.

Not much else in the tank (that I've ever seen) that could be feasting on my beauties.
So maybe now it's safe to go back in the water

 

[jdieck]

Good you could catch it. I chased one for months before I waslucky and a manthis for about two years!

 

[sscherin]

I had a brown crab in my old 55.
It came in on some LR I got and hid out for 6 months snacking on whatever it could catch at night.
It ate my green brittle star down to the disk over about a month.

It finally got big and brave enough to come out swinging at fish during the day.

I ended up hauling him and his rock out to a tub of SW then bated him off the rock with some cod.

About the only good thing he ever did was eat Aiptasia.

 

[GuySmilie]

<a href=showthread.php?s=&postid=11458055#post11458055 target=_blank>Originally posted</a> by sscherin
I had a brown crab in my old 55.
About the only good thing he ever did was eat Aiptasia.

Yeah, I notice that my scourge is on the rise again, now that Mr. Claws is gone.

 

[BryanM]

Hello Guy,
I have kept a brown brittle star in my reef tank for 4 years now. He has never come out while the lights are on. Occasionally he might reach a tenticle out if he thinks he can catch some myasis shrimp if it gets close to him. Very mild manored and easy to keep.
My guess is your clown fish is probably a victim of the crab , not the star.

 

[GuySmilie]

My brittle behaved the same way...until her demise. I could see a tentacle every now and then, but only saw her in all her splendor when I first brought her home.

And I have an update. Today, while vacuuming around and under some equipment, I did find a little Nemo-colored 'potato chip'. Looks like the little guy made a jump for it.

But that crab still whacked my shrimp and brittle star. Anyway, he's in jail now so all should be well from here on out...hopefully!