Bad Emerald Crab?

[BCSreef]

I have had many over the years and only one was a problem. It killed 3 maxima clams over a single weekend. I found empty shells 3 mornings in a row. I had about 6-7 other emeralds at the time. I figure it was that "emerald" because it was the only one that seemed to go crazy during feeding time. Upon closer examination, the bad one had pointy pincer ends (for killing and tearing up prey) versus the plier-like, blunt claws (for grazing algae) of the others. It was also a grey/green color.

I tossed a piece of shrimp attached to a string and within 5 minutes, it attacked and I scooped it out with a net.

To be sure, I added a new "test" maxima and 5 years later, it is alive and well.

There are more than one species of Mithraculus. Check the pincers and get rid of it if they are pointy and needle-like.

 

[Jimbhoy13]

Welcome to R2R.

 

[Sharkbait19]

Welcome to the forum!
It may have been testing to see if it was food, target feeding may calm him down.
I’d keep an eye on it and if it happens again, get rid of it.
I’m another one with a bad emerald, it made the decision easier by dying. Fascinating creatures but definitely a risk.

 

[Jeffcb]

Welcome to Reef2Reef!!!

If it stung him I doubt he will do it again. The are good cleaners.

 

[Sharkbait19]

Welcome to Reef2Reef!!!

If it stung him I doubt he will do it again. The are good cleaners.

Love that gif

 

[Fish Think Pink]

Hey everyone! So my nano tank has 2 clowns, a watchman goby, afew snails and an emerald crab.Yesterday I brought home my 1st long tip anemone. It found a good place to grip between 2 rocks and the sand, looks happy and healthy. This morning my emerald carb came right over to it, and pinched off a good chunk of a tentale!! My first instinct was to reach in there and pluck him right out! But then I think the tentacle that he pinched off stung him. He swiped at the stung claw and ran off. Do you think I should still remove the emerald crab? Or could he have learned his lesson?

Welcome and glad you joined. I'll be curious how this turns out long term...

 

[bnord]

I really wonder what we know about Emerald Crab species, subspecies and or geographic variation
have 2 in the 15, 3-4 in the 90 and 5-6 in the 180.
never seen a bit of bubble algae where a crab could go, and not aware of any coral snarfing
have tried to select for females, putting males in a rock acclimatization tank
buy nearly all from a keys base supplier

 

[DrZoidburg]

I agree I am surprised this happened. Never had a coral attacked by these guys. I have heard if they don't have enough food they can turn to corals. I can kind of sympathize with mr. emerald though. Snatch and grab haha. I always thought of them kind of like oscar the grouch. I like that about them. @bnord maybe? There is a red variety. Maybe they eat something entirely different in the wild. Maybe because the anemone of that region doesn't have as strong of a defense. Maybe he did learn his lesson?

 

[Manny’s Reef]

Hello and welcome to R2R.

 

[bnord]

I agree I am surprised this happened. Never had a coral attacked by these guys. I have heard if they don't have enough food they can turn to corals. I can kind of sympathize with mr. emerald though. Snatch and grab haha. I always thought of them kind of like oscar the grouch. I like that about them. @bnord maybe? There is a red variety. Maybe they eat something entirely different in the wild. Maybe because the anemone of that region doesn't have as strong of a defense. Maybe he did learn his lesson?

Kindred
i have had a few of the Red coloration, supposedly found more often on the reef instead of more inshore where other emeralds come from. However, in my LIMITED experience the reds are not around as long.
Not sure if others have had the same issue

 

[KevPool]

Welcome to R2R

 

[Reefstick555]

Welcome to reef2reef! You could try feeding the crab meaty food like pellets but personally I will never have an emerald crab in my display again overnight I had one eat about 30 zoa heads in a large colony it completely decimated them. Id be chucking the bugger in the sump

Oh! The sump...that would have been a good idea, hahaha. I stuck mine with a toothpick.

 

[Kiwi reefer]

Welcome to R2R

 

[attiland]

Hey everyone! So my nano tank has 2 clowns, a watchman goby, afew snails and an emerald crab.Yesterday I brought home my 1st long tip anemone. It found a good place to grip between 2 rocks and the sand, looks happy and healthy. This morning my emerald carb came right over to it, and pinched off a good chunk of a tentale!! My first instinct was to reach in there and pluck him right out! But then I think the tentacle that he pinched off stung him. He swiped at the stung claw and ran off. Do you think I should still remove the emerald crab? Or could he have learned his lesson?

I would remove it

welcome to R2R