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Saltwater Aquarium/hitch hikers crabs


QUESTION: Hey hi ... I got an established reef tank with corals and everything in it. Last time I used to have a crab but I removed it. Then suddenly yesterday I've notice another crab which is bigger and I suspect that crab to be nipping other fishes during the night till the extend that one of my dart fish lost the whole of it's dorsal fin and half of it's tail. Do you have any methods of removing the crab other than removing the life rock. I tried trapping it but it failed. Another thing that I've just noticed is that it seems there's a colony of crabs in my reef tank. I can see the tiny baby crabs swimming around when I turn everything off. The crab even ate my feather duster's crown! I'm really concerned and I hope you'll reply as soon as possible. Thanks a lot for your time.

ANSWER: sorry for the late response as this is a tine sensitive problem, you seem to be having quite a problem with your crabs but i am aware of several different types of traps that you can purchase online or at your local fish store. you could attempt at making your own trap with some food and a clear water bottle.

also i believe the best way to rid your tank of the crab and baby crabs is to get a fish that is a crustacean eater. There are many fish that will snack on crabs and that would be very helpful in your case.

hope that helps Artha.


---------- FOLLOW-UP ----------

QUESTION: Haha... nevermind, it's ok. I actually got rid all of the baby crabs manually but it's still the big one that i always fail to catch. I'm sorry to mention that it's a reef tank with cleaner shrimps n turbo snails. I looked up the net for suitable fishes like wrasse and trigger, but they are all no reef safe. I have a clown, a dottyback, 3 dartfish, a mandarin, a brown banner fish, an anemone, flower pot coral, hammer coral, frogspawn coral, finer leather and a leather coral. Do you have any idea to what fish that I can keep to control the crabs and at the same time will not harm these inhabitants ?? Oh by the way, traps are really useless as the big crab that's still in my is way too smart n sneaky to fall for a trap. I don't really know how did it ate all the bait but not getting trapped ?? Thank you once more for your precious time and advice :D

sorry to hear that you are still having troubles with the crab, its difficult to suggest some fish that will eat him because first off, i do not know the size of the tank, and also you have a cleaner shrimp. so likely any fish that will eat the crab will also snack on your cleaner shrimp.

however i have found that the niger triggers are one of the most reef safe triggers out there. he will most likely eat the crab while leaving all the other tank mates alone. however if you go this route i would suggest maybe removing the cleaner shrimp and putting him in a holding tank, or just something like this.

hope that helps a bit more than my last bit of advice.


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i have about 15 years of experience in the reefing hobby but have been keeping aquariums for about 20, i am up to date on all the latest equipment such as led lighting, dosers, the new tanks available such as the red sea max and i can help you with many creatures that most other people have never even kept before such as sehorses, cephs, and sharks and rays.


15 years in the reefing hobby and it has come to my attention this site needs some more informed experts.


masters degree in marine biology

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