Found a crab? of some sort

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loganj

Aquarium Advice Addict
Joined
Oct 25, 2002
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Location
Chatsworth, GA
I have noticed, in the past few days, if I shine the flashlight in the tank at night, something leaves a dust trail. This is a high speed, low drag critter! I found, in a hole in the rock, what appears to be a crab of some sort. It is about 1/4" in diameter, has fuzzy legs, two claws, and is a very light brown in color. He won't come out of the hole and I can barely see him up in there. Sorry...no photo...don't have the means to get one at the present time. Any ideas? Is this a common hitch hiker on live rock?
Logan J
 
Check out this link http://www.reefs.org/hhfaq/ and see if anything photoed looks like your crab.

Instead of using a real flashlight try to use one that gives off a red light. Its often been said that RED light is unditectible by nocternal critters. Maybe a red film over the flahlight or if you can find a red lens.
 
Crabs are very common hitchhikers on quality live rock. There are just too many species of crab to give a positive Id, even if you had a close-up picture.

You will need to remove the crab, if it's brown with hairy legs there's a 99.9% chance that it's a predatory species.
 
Crab

Well, no positive ID on the crab as of yet. Gonna try the red light on him and see if I can get a good look without spooking him. I am, going against what is probably very good advice, going to leave him be for now. All that's in the tank now are hermits, snails, and a peppermint shrimp. Not sure if any of these are on a crabs menu, but nothing has come up missing yet. I have found, as I get older, that I have a hard time killing anything. Even a crab. I wonder, if it is a predatory species, if I could feed him well enough to leave other tank inhabitants alone? I think I'll try putting a small piece of shrimp at his hole tonight and see if he'll eat it.
Logan J
 
Crab

Not that I can see...seems to be all light brown. I fed it a piece of krill the other night and he seemed to like it very much. I have been beating the bushes trying to find a pic of something that looks similar with no luck so far.
Logan J
 
crab

Crab, as best as I can tell from photos, may be the 7-11 crab. This means he has to go or become the sole inhabitant of the tank :( A word of warning to all who might do a search on crabs: Be sure to specify "saltwater" crabs or you will learn more about cooties and lice than you EVER wanted to know :lol: .
Logan J
 
LOL Thank you Logan, I'll remember that.
I have what sounds like the same crab, or something very similar to it. It was a hitchhiker on a shroom rock. I've had it for 6 months now and so far it only comes partially out of it's hole and only to grab food. I can't get it out of the rock unless I literally bust up that rock, so it'll stay for now.
 
hitcher?

how does a crab come along with a rock? Don't you see it when you by it? doesn't it dry out?

Ed
 
Crab

Apparently, crabs can live out of water for some time. I know if you go to the beach, you will see them scurrying all over the place at certain times. This rock was only out of water (when I got it anyway) for about 4 hours. How do you get one? This piece of Fiji rock has several caves in it that range from 1/4" to about 3/4" in diameter and of unknown depth. This crab was hiding in one of these...still is for that matter :). He is pretty small...probably about 3/16" in diameter not including his legs and claws. He made his first appearance about a week after the rock was put in the tank.
Logan J
 
To catch an unwanted crab:

1 - Find a tall smooth sided drinking glass
2 - rubberband some bait to a small piece of reef rubble
3 - Lean the glass against a rock near the crabs home
4 - place the baited pebble in the glass and leave it overnight
5 - remove the crab in the morning. This may take several attempts.
 
crab removal

Thanks for the tip...I would have never thought of that. Will try it this week.
Logan J
 
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