killer Emerald Crab

[MadSneak]

So last week I found my Sun Burst Anthias getting eaten by my emerald crab and shrimps, but I thought he had died for other reasons,, well I left it at that and today I found my emerald crab eating my Pearly Jawfish.... Grrrr!
Should I take him back to my LFS or put him in the refugium?

 

[don_chuwish]

Refugium with a little green puffer, see who wins.
No but really, could he have caught and killed the fish? I just don't know. Any reason to think the fish may have just died?

- D

 

[MadSneak]

Refugium with a little green puffer, see who wins.
No but really, could he have caught and killed the fish? I just don't know. Any reason to think the fish may have just died?

- D

lol...thats a good idea!
I know he was the killer, cause the fishes were just fine the day before I found the crab eating them.... I had seen him before bugging the fishes, but never thought he was ganna end up eating them..

 

[Wy Renegade]

Lot of people don't realize that as emerald crabs mature, they turn from herbivorous (juvenile) to carnivorous (adult). Truth is, no emerald crab is truly reef safe long term.

 

[MadSneak]

Yea and this crab doesn't eat just any fish... He ate two of the nicer and one of the most expensive fishes I had....GRRR! I feel like eating him myself! Lol

 

[mr_X]

I've always kept emerald crabs and have never seen one take down a healthy fish. On the contrary, they dart backwards when a fish swims by. I have 2 in my tank right now that are about the diameter of chicken eggs.
How long have you had these fish?
have you tested your water recently?

 

[rdnelson99]

I've always kept emerald crabs and have never seen one take down a healthy fish. On the contrary, they dart backwards when a fish swims by. I have 2 in my tank right now that are about the diameter of chicken eggs.
How long have you had these fish?
have you tested your water recently?

+1 (and a bunch more letters)

 

[MadSneak]

I've always kept emerald crabs and have never seen one take down a healthy fish. On the contrary, they dart backwards when a fish swims by. I have 2 in my tank right now that are about the diameter of chicken eggs.
How long have you had these fish?
have you tested your water recently?

All my parameters were on point. My emerald crab wouldn't back down to anything, I'd witness my Jawfish trying to get him out his cave and hi wouldn't even flinch. He didn't even move when I was trying to get the dead fishes out of the aquarium, he would try to attack me actually.... My emerald crab is evil..lol

 

[AquaRick]

I had an opportunistic killer emerald. He waited until a shrimp or fish would hide in a cave or get stuck in a rock. He would just go to town on them. Killed a cleaner, ate my 3 peppermints while they ate leftover seaweed i would feed to my tangs. I returned him to the LFS after i had him clean up my fuge a bit.

 

[Wy Renegade]

I've seen them take down healthy fish, especially at night when they were sleeping or resting either in the bottom or in holes in the rock. Bigger ones will take ornamental shrimp as well.

 

[MadSneak]

I had an opportunistic killer emerald. He waited until a shrimp or fish would hide in a cave or get stuck in a rock. He would just go to town on them. Killed a cleaner, ate my 3 peppermints while they ate leftover seaweed i would feed to my tangs. I returned him to the LFS after i had him clean up my fuge a bit.

I think thats what I'm going to do, put him in the fuge for a bit and then just take him back to my LFS!

 

[MadSneak]

I've seen them take down healthy fish, especially at night when they were sleeping or resting either in the bottom or in holes in the rock. Bigger ones will take ornamental shrimp as well.

Yea, thats exactly what mine would do, he just waited till night time and kill! Both of my fishes were healthy...

 

[Wy Renegade]

Here's a link, if you scroll down to Mithrax sculptus, you'll see in the reference that they can become fish killers.

SWcrabs2

 

[MadSneak]

Here's a link, if you scroll down to Mithrax sculptus, you'll see in the reference that they can become fish killers.

SWcrabs2

So this confirms that the emerald crab is guilty as charged! Case closed...lol

 

[mr_X]

I don't know if it does or not. I've seen many inconsistencies on line and I would do more research than take the word of one person, or two even.
I'm not saying it's impossible, because people in this thread said they saw it with their own eyes, but i don't think it's a regular occurrence.
I've had tangs that ate corals and known coral eaters that didn't.

 

[MadSneak]

I don't know if it does or not. I've seen many inconsistencies on line and I would do more research than take the word of one person, or two even.
I'm not saying it's impossible, because people in this thread said they saw it with their own eyes, but i don't think it's a regular occurrence.
I've had tangs that ate corals and known coral eaters that didn't.

I'll keep watching him to see... I might be wrong!

 

[Wy Renegade]

I don't know if it does or not. I've seen many inconsistencies on line and I would do more research than take the word of one person, or two even.
I'm not saying it's impossible, because people in this thread said they saw it with their own eyes, but i don't think it's a regular occurrence.
I've had tangs that ate corals and known coral eaters that didn't.

Yep, excellent point Doug - there are no hard and fast rules in this aquarium game.

 

[AquaRick]

Exactly. It's pretty hit or miss on the behaviors of fish and inverts. Each individual has its own personality and behaviors that may or may not line up with the general observed behavior of the specie. I returned the killer emerald to the LFS, but i still have 2 others in my DT. Best to deal with any issue as it comes up since behavior can be unpredictable. Rather keep them around as they're fun to watch.

 

[joy13]

I can see it bothering a shrimp after it molts. I have seen an emerald crab get upset at a wrasse picking at it while it was eating algae and waved its claw but as far as trying to grab it it didn't. Even a sleeping fish when nudged usually goes into a sleep swimming mode which is strange because they are bumping into things all over the place.

I would look for another cause of death of the fish including collection methods. When all that has been ruled out then blame the crab.

 

[MadSneak]

I can see it bothering a shrimp after it molts. I have seen an emerald crab get upset at a wrasse picking at it while it was eating algae and waved its claw but as far as trying to grab it it didn't. Even a sleeping fish when nudged usually goes into a sleep swimming mode which is strange because they are bumping into things all over the place.

I would look for another cause of death of the fish including collection methods. When all that has been ruled out then blame the crab.

When you say collection methods, what are you referring to? Thanks