Help needed desperatley! To catch crabs...

robhart60

robhart60

Member
Hi,

I've had my reef aquarium for 8 months and have been doing well until recently. Had a few sudden deaths including, a Malu Anemone, Dancing Shrimp and a starfish, all within a month.

I had suspicians that the crabs living on my rock might be the problem and only recently discovered that they're a problem in aqauriums, and could be whats killing my livestock.

I've identified one species being the Gorilla crab of which I have atleast 6 in my 65g tank. I also have at least 4 other crabs that I don't know if there a danger or not.

I decided to get rid of the Gorilla crabs by using the bottle cut in half etc trap. But it hasn,t yet worked. (4 days in) All I've captured is my Dancing Shrimp and a Hermit crab!

Is there any other way of getting rid of these crabs? I read on another post here about using a glass tipped against the rock. I can't do this as most the Gorilla crabs live under a cave on the sand. I also read that removing the rock and putting it into cold water would work but wasn't sure if this would do lasting damage to the rock?

I'm starting to get desperate as yesterday I noticed my yellow cheeked Goby has had his tail bitten or something probably in the night as he likes sleeping under the rock were a Gorilla crab lives.

Any help would be much appreciated.
 
Royalscott

Royalscott

Member
take the rock out, hold it over a bucket, and pour seltzer water into the holes where the crabs are. It works for getting out Mantis shrimp.
 
goldenmean

goldenmean

Well-Known Member
Will it harm the rock at all?
Click to expand...
very little.
If there are sponges on the rock exposure to air will kill the sponges.

I had a lot of luck with the bottle trap and patience.
i also got some of the gorilla crabs with a wooden skewer. I put a little bit of fresh shrimp or squid on the end of the skewer and used it to lure the crab out of his hidey hole. Than Stab! Crab-ka-Bob! fire up the grill.
 
robhart60

robhart60

Member
Excellant idea!! I'll try that. I watched them last night when the lights went out, and there's more than I thought! So iv'e got my kebab sticks ready, no more mr nice guy!

Thanks for your help, i'll let you know how it goes.
 
robhart60

robhart60

Member
Excellant idea!! I'll try that. I watched them last night when the lights went out, and there's more than I thought! So iv'e got my kebab sticks ready, no more mr nice guy! :guns:

Thanks for your help, i'll let you know how it goes.
 
Chris3859

Chris3859

Member
We always used chicken wings tied to a string and a net when we went crabbin' at the beach. I wonder if this would work in an aquarium?? LOL
 
robhart60

robhart60

Member
I still haven't caught any crabs! (Caught my Goby last night in a trap) The traps just don't seem to be inticing them enough? And I never see them far enough out to catch them myself.

Last week I took out a few of the rocks and poured seltzer water over it and also put it in cold water, nothing came out?! And there were definately crabs in them as I could see a leg stickin out when I was pulling it out the tank.

Is there anything I could buy that would kill the crabs for me? Like an invert or something?
Also has anyone had any success using Aqua Medic Trapest as I was thinking of trying this out instead of the homemade bottle traps.
 
robhart60

robhart60

Member
I've now caught 3 crabs in the last two nights. :dance:
But not with a scewer and not with a bottle crab trap, I used a long glass with bait at the bottom and it seems two be working. I caught two crabs one night in one trap!

I've still got atleast 6 more to get, including one massive crab that I only recently discovered, and I've just seen it taking swipes at my Goby :banghead: I tried to force it out its position but it went through the rock to somewere else.

I'm also very worried as to what crab this is? it's much larger than the gorilla crabs iv'e caught and seems even more aggressive!

It's body is dark brown to black, very shiny with white stripe on it, it's completely smooth apart from the back 4 or so legs. :read: Does anyone know what its species might be?
 
rlcline76

rlcline76

Active Member
Wow...you certainly have a circus in your tank! It the goby the only fish in there. If so and you can easily catch him toss him in a quarantine tank (if you have one) until you can be relatively sure you have rid yourself of these crabs! Oh, and I think I speak for several of us when I say that I want pics!
 
vdituri

vdituri

Well-Known Member
My solution to this would be buy a mantis shrimp.
Set him to work in your tank.
Then when the crabs are gone you just have to catch one really big mantis.
The mantis will have so much food in crabs he shouldn't bother any of the fish.

:bluenod:
 
robhart60

robhart60

Member
I caught another Gorilla crab last night. (4 now in total) Iv'e also attached some pics as requested. Thanks for the advice. Getting a Mantis shrimp sounds like a good idea but they seem to be coming out easily enough with the right trap in the right places. I also don't have a big enough quarintine tank to put all my fish in. I have 9 fish and some inverts. Iv'e left the trap in place during the day so the Goby's no longer in danger as it's blocking the spot were the large crab is a danger to passers by.
 

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lcstorc

lcstorc

Well-Known Member
That's a lot of crabs. Did you get your rock from Tampa Bay Saltwater or where did they all come from?
 
robhart60

robhart60

Member
Got the LR from my LFS, 27kg in total. Had it for 8 months. It came from Indonesia I believe. I was beginning to wonder if the crabs were reproducing or something? Can't wait to get this large crab out, it looks a lot different to all the others. and it's clever. Probably why I had never noticed it till recently. Now I know were its normally at I think i'll get it soon. Watch this space! :guns:
 
BEELZEBOB

BEELZEBOB

Well-Known Member
vdituri said:
My solution to this would be buy a mantis shrimp.
Set him to work in your tank.
Then when the crabs are gone you just have to catch one really big mantis.
The mantis will have so much food in crabs he shouldn't bother any of the fish.

:bluenod:
Click to expand...

i think this is by far the best suggested solution yet!:apimp:
 
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