good or bad??

[Ruth]

Those are evil evil evil and I have a crap load in my 190 that I am trying to trap and one in my 230 that I just saw last night. I caught one in my 230 about a month ago that had grown to almost 4" across. The last batch of live rock that I got was really infested with those, I call them Son of Sam crabs.

[Matt]

There's a handy mnemonic: Red eye, must die.

[TheReefGeek]

Looks like a rock crab, and they take out fish.

[Willow]

red eye means die.

[Raf]

Well, we gots a tank with triggers....

honey, you know what to do

[rickjames]

In every nook and cranny of my rock I have those things. Didn't think they were a big deal, still aren't causing any problems but a whole patch of zoos on my rock has slowly disappeared so I am beginning to wonder. I have tried the pop bottle trap but that didn't work.

I also have a ton of filter feeding crabs that hitch hiked, they are cool little guys.

I swear must have gotten at least 100 hitch hiking crabs in total! An added benefit though is that all night they pick the rock clean of any algae.

[TheReefGeek]

When the rock crabs get big enough, they will take out pretty large fish. I have seen it right in front of my eyes, a black rock crab was hiding in the rock, the a huge pincer whipped out and grabbed a sizable fish (cant remember which one right now), about 3" long, and it was dead.

This was at Aquarium Illusions in their large display tank, they had no idea they had a rock crab until they saw the aftermath.

Maybe not all rock crabs get this big or agressive though, but if you can remove them, I would.

[Chin_Lee]

just use interceptor. get rid of red bugs, get rid of crabs, BUT also get rid of pods, shrimps, hermits.