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Emerald crab keeps killing my clown fish!


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#1
diablovt750

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A while back I posted a thread about my emerald crab holding and eating my dead clown fish. Everyone in here that was kind enough to reply all agreed that the more then likely case was that the clown had died and then the crab just found him before I did. The other day I found this beautiful clown fish at the LFS! It was a maroon clown with blueish stripes and black spots on all of its fins. The LFS sold him to me for $10 which I thought was a steal. The fish was perfectly health and was eating very well. I had him for around 2 weeks.
Yesterday I was watching him swim around the tank and the emerald crab was sitting out out the rock. The fish swam by him and he reached up very fast, grabbed him and went under the Live Rock! I haven't saw the Clown since!
The emerald is rather large, probably around 2" across and he is in my 24g nanocube. He was tiny when I bought him. Has he out grown the tank and thats why he is aggressive or is this normal behavior. I will try to get a pic of him, maybe he just looks like an emerald crab but could be a different kind of crab? I have even been giving him food to try to prevent him from attacking the fish but I guess I didnt succeed. Please tell me how I can get him out of my tank QIUCK! I dont want to loose any more livestock! Thanks in advance

#2
kthehun89

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yeah put a pic up, might be another type of crab
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#3
cheryl jordan

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I agree I do not think what you have is indeed an emerald as they are algae eaters

A pic of your crab would really help.

:)

#4
spanko

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All crabs are EVIL!!! There I said it and I'm not taking it back!

That said crabs are opportunistic feeders. Emerald ([i]Mithrax sculptus/i]) are omnivores. If your tank doesn't have enough food for it to pick at and it is not getting fed enough it will do what it has to in order to eat. Must be pretty big to be able to grab a fish out of the water column though.

#5
cheryl jordan

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All crabs are EVIL!!! There I said it and I'm not taking it back!

That said crabs are opportunistic feeders. Emerald ([i]Mithrax sculptus/i]) are omnivores. If your tank doesn't have enough food for it to pick at and it is not getting fed enough it will do what it has to in order to eat. Must be pretty big to be able to grab a fish out of the water column though.


I have never had an emerald crab even go after a dead tank inhabitant, but I would not put anything past a crab or a shrimp.

I have seen really large emeralds that were well behaved.

I would not stand for crab eating my clowns he would be out of that tank so fast.

:)

#6
Dmarmontello

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Dude.. I had two emerald crabs.. one grew very quickly and beheaded my Fire Shrimp. The other is peaceful and doesn't bother anything. I would get rid of yours, people say they only eat algae until you see yours eat a $40 shrimp.
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#7
Primeval

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A while back I posted a thread about my emerald crab holding and eating my dead clown fish. Everyone in here that was kind enough to reply all agreed that the more then likely case was that the clown had died and then the crab just found him before I did. The other day I found this beautiful clown fish at the LFS! It was a maroon clown with blueish stripes and black spots on all of its fins. The LFS sold him to me for $10 which I thought was a steal. The fish was perfectly health and was eating very well. I had him for around 2 weeks.
Yesterday I was watching him swim around the tank and the emerald crab was sitting out out the rock. The fish swam by him and he reached up very fast, grabbed him and went under the Live Rock! I haven't saw the Clown since!
The emerald is rather large, probably around 2" across and he is in my 24g nanocube. He was tiny when I bought him. Has he out grown the tank and thats why he is aggressive or is this normal behavior. I will try to get a pic of him, maybe he just looks like an emerald crab but could be a different kind of crab? I have even been giving him food to try to prevent him from attacking the fish but I guess I didnt succeed. Please tell me how I can get him out of my tank QIUCK! I dont want to loose any more livestock! Thanks in advance



Wow. I agree with the rest - post a pic of this thing

Edited by Primeval, 14 May 2010 - 07:33 AM.


#8
cheryl jordan

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Most literature says herbivore.

Some say omnivore.

But I agree with spanko, if your tank does not have enough algae it may take to eating anything it can get.

#9
meganistkrieg

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Also curious to see a pic - I wouldn't think my emerald moves quickly or aggressively enough to do that. He's very clumsy! :o

I have a 240 gallon that is six feet long and my bottlenose seems to be having territorial issues with the blue tuna. Do you think they will eventually get it figured out.


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#10
diablovt750

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All crabs are EVIL!!! There I said it and I'm not taking it back!

That said crabs are opportunistic feeders. Emerald ([i]Mithrax sculptus/i]) are omnivores. If your tank doesn't have enough food for it to pick at and it is not getting fed enough it will do what it has to in order to eat. Must be pretty big to be able to grab a fish out of the water column though.


This is definately not the case because I have been feeding it 1 silverside a day to try and prevent it from killing anymore livestock but that has obviously not worked. The other day I tried to get him out of the tank with my long grabber and he was held on so tight that it picked up the whole rock that it was on with him! And it wasnt that small of a rock neither!

Heres the Pics There not that good so bare with me:

PIC 1: Luring him out with a silverside, which you can see in the bottom right corner of the pic. He almost grabbed my sixline wrasse running for the peice of fish, Good thing the wrasse is fast!

Posted Image

PIC 2: Him running back under the rock with his prize

Posted Image






And by the way the guy did say that it was an emerald crab in the store despite it being red. I also bought a green one when I bought this one but I shortly after found him ripped apart at the bottom of the tank!

#11
cheryl jordan

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Yea you want to get rid of him before you add anymore fish.

I thought we were talking a green emerald crab, so I have no clue how aggressive yours might be.

I have never had a problem with the green variety, but you always run the risk.

#12
meganistkrieg

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Definitely a red mithrax but wow, I've never heard of one being so murderous! :o Give him to someone with a predator-friendly tank??

I have a 240 gallon that is six feet long and my bottlenose seems to be having territorial issues with the blue tuna. Do you think they will eventually get it figured out.


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#13
diablovt750

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And there is also plenty of algea for him to eat! That was the whole reason why I bought them in the first place! The LFS said put 2 in there some hermits and some snails and keep the lights off for around 3 days and my algea problem would be gone. 3 days later I still had plenty of algea.

#14
pyronus

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Thats definitely not an Emerald Crab...

#15
spanko

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Give away is the pointed claws, designed by nature to be able to dig into areas where the meaty stuff is. Should have pulled him and the rock out while you had the chance. He needs to be banished to somewhere that he can do no harm.

#16
meganistkrieg

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Give away is the pointed claws, designed by nature to be able to dig into areas where the meaty stuff is.


I'm not sure I see the pointy claws you're describing. It looks exactly like a red mithrax to me (like in this picture http://rapturereptil...oral_pic_25.jpg ) complete with scoopy-claws.

Doesn't really matter though - a killer is a killer whatever the taxonomy!

I have a 240 gallon that is six feet long and my bottlenose seems to be having territorial issues with the blue tuna. Do you think they will eventually get it figured out.


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#17
Aquanist

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Yeah. Thats not a mithrax. Cast it into the abyss, where it belongs.

file_zpsf0380bf1.jpg


#18
ajmckay

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+1 to red mithrax crab. They're very similar to the emerald crabs (also mithrax crabs).

They're listed on some sources as herbivorous (spoon-shaped claws for scraping algae off rocks vs. the sharp pointy pincers of carnivorous crabs) but given the right circumstances any crab/shrimp/fish will eat another animal.

2" is pretty big, but it will probably become larger. It's probably not eating the algae in your tank because you're feeding it silversides. They're not completely dumb, if they know that they will be fed something meaty they'll go after that instead. Now it's probably developed a taste for fish and thus fish have become it's preferential prey.

If I were you I would remove the crab and give it to someone else. At the very least someone will likely have a predatory fish/shrimp which would make a nice meal of it (or you could mash it up and feed it to your fish). I don't think you'll ever get the crab to not attack fish though.

#19
kamikaze_fish

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Definitely not an emerald crab. I've been lead to believe all emerald crabs are...you know...emerald colored.

#20
0utkast

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Get rid of him obviously.......the question is how? Since he has killed a few of your fish id suggest this!!



#21
kamikaze_fish

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Also, if I tried to give my emerald crab a silverside and put it near him, he would look at me like "get off me dude" and go away instead of grabbing the silverside.

#22
spanko

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Get rid of him obviously.......the question is how? Since he has killed a few of your fish id suggest this!!


HA! I approve of this message!

I'm not sure I see the pointy claws you're describing. It looks exactly like a red mithrax to me (like in this picture http://rapturereptil...oral_pic_25.jpg ) complete with scoopy-claws.

Doesn't really matter though - a killer is a killer whatever the taxonomy!



Yup you are correct doesn't really matter as it is a killer.
Just looked pointy to me in this picture.
Posted Image

#23
jaynkeel

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HA! I approve of this message!




Yup you are correct doesn't really matter as it is a killer.
Just looked pointy to me in this picture.
Posted Image


That was classic he takes him behind the rocks and continues to beat the crap out of him, Someone needs to do a voice over with Joe Pesci on that one.

#24
Primeval

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I'd be royally pissed if my LFS sent me home with this and told me it was an emerald.

#25
vinhle00

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Get rid of him obviously.......the question is how? Since he has killed a few of your fish id suggest this!!



LOLOLOL OMG wow....