Emerald crab eating habits

[Haskellf]

I've added an emerald crab to my tank and he's starting to make quite a mess of things. He's been attacking my Live Rock with a vengence, leaving all kinds of matter on the sand... i.e. stuff that used to grow on the live rock, but not the actual rock itself

I started this tank about 6 weeks ago and all there is in this tank are 40 lbs of live rock, I think 20lbs of live sand, 1 red crab of unknow origin and 2 emerald crabs - although the larger of the two is causing the mess.

Is this normal behaviour of an emerald crab?

Besides filtration, what other creatures would you recommend to essentially cleanup after this dead live rock vegetable matter that's accumilating on the sand? Would a Lawnmower Gobie eat this stuff?

Once again, thanks for everyones help in advance

 

[Len]

Yes, it's normal. They scrap an scrap and scrap

A lawnmower blenny is good at eating short turf algae. If that's what you have, the blenny will serve your purpose well.

 

[elreydelospesces]

That very thing is what I like about my mithrax crab. He doesn't bother my coralline but plows through the stuff I don't want on my rock. Other critters like hermits eat the detrital crud he cleans up. Maybe you should look at getting a good cleaning crew for algae or detritus or both. But with your tank being so new you may not yet have enough stuff for them to eat. Turbo grazer snails for example will die if they don't have enough algae to eat.

 

[Anonymous]

Watch out for those lawnmowers, though, they have been known to nip at sps corals - of course if you don't have any of them or don't plan to get them, no problem!

 

[Haskellf]

That very thing is what I like about my mithrax crab. He doesn't bother my coralline but plows through the stuff I don't want on my rock.

Interesting, mine seems to plow through everything, even the coralline... however, my tank is a new established system and the coralline and other vegatable matter on the live rock are mostly dead, so perhaps that is why it is cutting it all away. I don't have that much algae, just as yet... just enough for the crabs to eat but most likely i will have to supplement their diet.

Do you think that 1 Red Crab (of unknown origin - eats the algae though) and 2 emerald crabs are too many for a 20 gal flat back hex tank that was established 6 weeks ago and currently only gets sunlight from outside sunlight, via the windows?

 

[elreydelospesces]

That certainly doesn't sound like too many for me. I know some people who have dozens assorted crabs and another dozens of assorted snails in their tanks with no trouble. I have a 29g and have approx: 12 very small red leg hermits, 1 mithrax, 1 cleaner shrimp, one large blue leg hermit, 8 small bumble bee snails and 8 mexican turbos. I also have two fish. But I have a lot of rock and am still trying to eradicate the lasting effects of a nasty algae outbreak. Some people can only keep a few because their nutrient levels and subsequent algal growth is very low. It depends on your tank, water quality and filtration.

 

[Haskellf]

8 small bumble bee snails.

Not to go off topic, but I used to have Bumble Bee snails from my last aquarium and they are the best snails I ever had. They are the fastest algae eating snails by far compared to any other snails.. which might account for their price tag.... anyhow, thanks for the info

 

[ChrisV]

Yes I have grown kinda fond of the bumble bee snails also... Ive heard they will eat corralline and other things I like but I never had a problem. Also my bumble bee is the longest living snail ive had, going on a few years now, the little thing hasnt grown from what I can tell though.

-CV

 

[Anonymous]

I have trained my mithrax crab (or rather, he has trained me) to take Seaweed Selects. He'll come to the front of the tank and wave his claws, and I'll get a bit of Seaweed Selects down to him. Then he's off for the cover of LR to chomp to his heart's content.