Emerald- How big is too big??

[eederise]

I have read in a couple of different places that emerald crabs are "reef-safe" so long as they don't get too large, though I've been unable to define "too large". My E-crab is currently being charged with ripping open a feather duster tube, ripping the crown off of a featherduster(spearate occasion), severing peices of my Sand sifter's arms, and chopping a zoa polyp in half. I have personally seen him consume nearly an entire Green Chormis(1-1/2") in about 30 minutes. The fish was already dead and floated up out of a rock crevace where he grabbed it and starting ripping it apart.

I havn't truly witnessed anything except the feather duster tube tantrum and the fish consumtion, but does anyone know what else could be in my tank that would cause the starfish to loose limbs, the severed FD crown, and the zoa polyp damage? (My current livestock includes: 2 green chromis, 1 sand sifter, 1 cleaner shrimp, 2 peppermint shrimp, 3 small zoa polyp colonies, 1 star polyp colony, and a few hermits/snails)

I'm thinking of returning him to the LFS to exchange for a smaller one.

Once and for all, how big is too big? To get a perspective of his size, the featherduster tube below him is about the diameter of a pencil.

Thanks all,
Shaun

 

[dc]

When they start destroying stuff, they are probably too large. I had a huge one that was a great citizen in my tank.

 

[Paintbug]

looks like you have a male. these guys can get aggressive. if i dont feed mine for a few days, he starts looking for a meal. i feed mine a small piece of algae sheet about every 2-3 days. maybe a 1x2" strip. seems to keep him at bay. they will eat a dead fish for sure, thats part of their job in the tank. mine is about 1 1/2 years old, and about 4" across from the tips of the claws.

 

[papagimp]

4" across, nice, I never had one live long enough for that, they seem to disappear in the rockwork and havn't seen em since. Started w/ four of them and to this day I've only seen one out and about. never had a problem with him eating anything he wasn't supposed to but have never been able to convince the guy that bubble algea is better tasting than fish food.

 

[Paintbug]

yep hes a big guy .

 

[Big Boy69]

I have a big red/maroon one the same but different color.
He's abeen a model citizen also. I have 3 other smaller one in the tank also. I'll feed the big guy a piece of Nori and sometimes while he's eating it the Tang will come and snatch it from him.

 

[kass03]

Starfish can lose the tips of their arms when they are starving or when not acclimated properly (which you can do it right but maybe not at the LFS or where they got it)

Zoa's can have preditors such as nudi's or sundial snails (read more about that in the zoa forum).

Usually these animals will only pick on something if it's dead or dying and not kill it but there are some that will kill things I have heard.
I think alot of people see something dead and are quick to blame something in the tank when not really knowing for sure because they did'nt see it.
Alot of times things die in your tank and you never find out why. At least that's been my experience.

kass

 

[jeffltodd]

I had 3 Emeralds in my previous tank - all were just fine. My only problem was when I was feeding my anenome, I had to make sure to leave about 1/2 a silverside for the crabs or they would reach into the anenome's mouth and steal the food!

 

[eederise]

Thanks for the input. I've decided to bring the crab back to the LFS along with the mangled sand sifter. The sifter only has about a half an arm left by the time everybody in the tank had a go at him. I've seen all the shrimp and my arrow crab eating off of him in turn. Don't think I'll be getting another one.

 

[kappaknight]

All the critters in the tank will eat dying things. I once thought bumblebee snails were the cause of my dead clam but it was probably some wrasse who nipped at it and the snails cleaning up the rest.

I've had pretty good success trading in bigger crabs for smaller ones.

Also you should check out the video in my blog for a scary emerald experience.

http://reefinabox.blogspot.com/2006/07/bully-eviction-program-part-i.html

 

[eederise]

Nice footage (That crab should be spanked). In a way I'm glad to see that I'm not alone in this. Anyway, my green little friend is no longer a part of my little reef as he has been returned to the LFS.

 

[jnb]

I love emeralds but only ask for females - over the last 2 mths I have 2 mis behavers - got them and they were males - going to ask the lfs to be more careful finding females and check them myself

 

[dc]

Eww. food chain. I've always liked emeralds, but I'm aware that they are opportunists. That little guy was definately in the wrong place. Was it an emerald also?

 

[jsc4354]

How can you tell the difference between male or female?

 

[jnb]

Males the underside "apron" is pointed like the Washington Monument

In a female, the apron is rounded like the nation's Capitol Dome, .

<a href=showthread.php?s=&postid=8289581#post8289581 target=_blank>Originally posted</a> by jsc4354
How can you tell the difference between male or female?