Help! Found my emerald crab and Scarlet-Legged Hermits Eating my Clown Fish!

[meagle]

Hi All,

 

At the moment my tank has a number of various snails, two emerald crabs, a few scarlet-legged hermit crabs and two clown fish. An hour ago I checked and both fish were swimming around. I just came out to check again and one clown fish was missing. I looked around the back and saw that the emerald crab had him in his grip and he was dead. Two hermits were also joining in on the action.

 

I have a few question:

 

1. Are the emerald crabs predatory to fish? Is this normal behavior? Or is it more likely the fish died within that hour and the crabs took advantage?

 

2. Should I leave the fish in there for them to eat or should I remove the dead fish?

 

 

 

Thanks for all of your help. A little lost here.

 

 

Matt

[flooddc]

Sorry to hear.

I have those crabs in my tank too with no issues. Maybe your fish died and the crab takes it. Let him finish his meal.

[Origami]

They are opportunistic predators, but odds are in favor of a healthy fish not becoming a victim. It's far more likely that the fish was sick and the opportunity presented itself.

 

If it's large relative to the size of your clean up crew, I would remove the fish while it's in sight and accessible. If small, they'll probably do a good job of cleaning it up. If in doubt, remove it while you have it in your sights.

[Ryan S]

1. Are the emerald crabs predatory to fish? Is this normal behavior? Or is it more likely the fish died within that hour and the crabs took advantage?

Yes they are. Caught my emeralds doing the same thing. I will never have emerald crabs again. They WILL catch and kill fish. Simple as that.

 

2. Should I leave the fish in there for them to eat or should I remove the dead fish?

Remove the fish. Remove the emeralds. Flush both.

[meagle]

They are opportunistic predators, but odds are in favor of a healthy fish not becoming a victim. It's far more likely that the fish was sick and the opportunity presented itself.

 

If it's large relative to the size of your clean up crew, I would remove the fish while it's in sight and accessible. If small, they'll probably do a good job of cleaning it up. If in doubt, remove it while you have it in your sights.

 

Thanks for the advice. I went ahead and removed him. He never took well to the tank like the other clown. He also never ate well and always seemed a little stressed. Still, a bummer.

[Brian Ward]

1. Are the emerald crabs predatory to fish? Is this normal behavior? Or is it more likely the fish died within that hour and the crabs took advantage?

Yes they are. Caught my emeralds doing the same thing. I will never have emerald crabs again. They WILL catch and kill fish. Simple as that.

 

2. Should I leave the fish in there for them to eat or should I remove the dead fish?

Remove the fish. Remove the emeralds. Flush both.

 

I've found them to be opportunistic predators as Tom mentioned. I've never had an emerald crab catch and kill a healthy fish. I have had my clean-up crew devour a fish that has died within an hour so this is normal behavior for the crabs and snails in your tank.

[davelin315]

A crab is a crab - meaning that some will attack fish, others will not. Emerald crabs are no different. Even though they are classified as being part of an algae clean up crew, they are really omnivores like all crabs. I didn't put crabs in my reef and only went with snails because I didn't trust the crabs.