safe crabs?

[fuzzy]

Hi everybody, this is only my second post so please excuse me if its a stupid question.

I wanted to know what kinds of crabs or other critters are good to keep down algae on live rocks. I've heard mixed things about hermit crabs safe or not safe for corals? Thanks for the input

 

[danmhippo]

No crab is truely safe for reef, as far as I know. Small emerald crab may be OK. But other then that, the only one other commonly sold crab that may be reef safe is the filter feeding type porcelain crab.

 

[robbinson]

red legged hermits and scarlet reef crabs are reef safe crabs and commonly used in the hobby to control algae on live rock. Blue legged crabs have a reputation for eating snails. Mitrex (emerald) crabs are also reef safe. Sallylightfoot crabs have a mixed reputation.

 

[tazdevil]

robbinson, you posted

Mitrex (emerald) crabs are also reef safe.

Not entirely true. There have been multiple postings of emerald (mythrax) crabs attacking/eating fish. I must agree with Danm, the only "safe" one would be the filter-feeders. Even some of the "reef safe scarlet hermits" have been known to be villians of certain crimes at one time or another. Just ask tangirl (btw, why the continued silence from the girl, figured the "blowover" would be finished by now).

 

[dvb]

I have red legged hermits as well as dwarf zebra hermits. They may eat my snails, but I have never witnessed it. They have never bothered any of my corals or anemones.

Emerald crabs are supposed to like bubble algae(Valonia sp.). I had one that ate it, but he got too big and started harassing my fish. I traded him in for a small one, which hasn't touched the bubble algae.

 

[Anonymous]

i have noticed that crabs are not needed to keep algae down.

the little grazing that a properly maintained tank needs is very minimal.

your bristleworms could keep up with the load.

crabs are a pain. they are always into mischief (knocking things over, harassing other inhabs...)

they also increase bioload, which in turn can create more algae.

if you must have them, i would recommend the scarlet hermit, zebra hermit, or blue leg hermit.

valonia and hair algae are not taken into account in this statement.

 

[Anonymous]

Scarletts are the only one I like. I've never seen mine harrass anything. they may claim on a stoney coral from time to time, but they don't do any harm.

I hate the blue leggs. They do Kill snail for there shell. Mine did even though there were plenty of spare shells in the tank. I turned the blues into yard pets!

Louey

 

[fuzzy]

Thanks for all the input. It gives me a few things to think about.

 

[dizzy]

No crab is truely safe for reef, as far as I know. Small emerald crab may be OK. But other then that, the only one other commonly sold crab that may be reef safe is the filter feeding type porcelain crab.

I thought that some of the commensal crabs that live in the pocilliporas and acroporas were also safe. I know there are a few badies that can hide in them as well, but I thought some of the Xanthiid crabs benefited the hosts.

 

[SPC]

Well I must put my vote in for the (true) Mitrex sculptus. If you will notice the ends of their claws are flat which indicates to me that they are used for grabbing and pulling as opposed to cathing animals. I have 4 in my 180 and have never seen them bother any animal, in fact they are so slow, that the fish would have to be in pretty bad shape for these guys to catch them IMO.
Steve

 

[DrGrotto]

I have two Emeralds in my tank, one had grown to be quite large and he DOES threaten my fish but so far he hasn't been able to get one. They do like to climb all over your corals though...

Hermit crabs are a pain in the butt and they are NOT worth it.