Could this crab be eating my fish?

[reefer1970]

I believe its an emerald crab that should be harmless but it is all I can find in my tank that could be the culprit. Missing loads of medium sized fish with no remains found. Lots of CUC. second pic shows possible claw marks on Singapore Tang. Crab is 1 1/2 inches

 

[Dkuhlmann]

Absolutely it can be. I caught mine after it had eaten one Royal Gramma which I thought had just died. Then I got a replacement for it and caught the Emerald green crab eating it in it's night time sleeping place. He now lives in my sump along with all of the other murderous bastards.. the blue legged hermits. :hammer:

Emerald crabs are harmless IF they have lots of algae to eat and they're not too big. Once their shell gets over an inch all bets are off. The only crab I allow in my DT now is the scarlet legged hermits. They are very well behaved and great at cleaning the rocks.

I was doing some work in my sump a few weeks ago and saw the Emerald and he is now a HUGE beast. I'd guess his shell is 2" from point to point.

 

[GypsyReefer]

I believe its an emerald crab that should be harmless but it is all I can find in my tank that could be the culprit. Missing loads of medium sized fish with no remains found. Lots of CUC. second pic shows possible claw marks on Singapore Tang. Crab is 1 1/2 inches

I have a coral banded terrorizing my fish and eating crabs. If you have one of those it me be the culprit.

 

[jj5]

I had a Green Brittle Star that was eating anything it could. It ate a 3" sea slug almost as fast as I put it in. Even the pet store doesn't want him. They called them evil. He now lives in the darkness of the sump.

 

[reefer1970]

Thanks guys, I think I got lucky when I caught him today and will watch for anymore missing fish before adding more

 

[Bongo Shrimp]

Emerald crabs do not catch healthy fish and eat them. Many people claim they can but have no evidence to back that claim. I challenge anyone to find or capture video evidence of an emerald crab catching a perfectly healthy fish. They are not aggressive predators but are scavengers or opportunistic predators at best. If you find one eating a fish, the fish was either already dead or very compromised when the crab got it in its claws. The claws on emerald crabs aren't even made for grabbing fish, they are for plucking at algae.

The marks on that angelfish are something else, possibly parasites but fish diseases are not my expertise.

Coral banded shrimp are indeed aggressive although they also won't be pulling healthy fish out of the water other than MAYBE a very small Trimma or Eviota goby and even those would need to be unhealthy to be caught.

Now a big green serpent star can definitely catch small fish. IDK about them eating a sea slug as that's not really in their diet and most are toxic but if it was hungry enough I guess it's possible.

 

[slapshot]

Emerald crabs do not catch healthy fish and eat them. Many people claim they can but have no evidence to back that claim. I challenge anyone to find or capture video evidence of an emerald crab catching a perfectly healthy fish. They are not aggressive predators but are scavengers or opportunistic predators at best. If you find one eating a fish, the fish was either already dead or very compromised when the crab got it in its claws. The claws on emerald crabs aren't even made for grabbing fish, they are for plucking at algae.

The marks on that angelfish are something else, possibly parasites but fish diseases are not my expertise.

Coral banded shrimp are indeed aggressive although they also won't be pulling healthy fish out of the water other than MAYBE a very small Trimma or Eviota goby and even those would need to be unhealthy to be caught.

Now a big green serpent star can definitely catch small fish. IDK about them eating a sea slug as that's not really in their diet and most are toxic but if it was hungry enough I guess it's possible.

I agree. I'd like to see a better picture of your angel so we can diagnose. In what time period has the fish disappeared? I know you said you took the crab out but I suspect you have another problem. Could even be a Bobbit Worm.

 

[sam.basye]

My emerald is rather large at 2" wide with big claws. At the end of each claws looks like cymbals it uses to grab algae.
Doubt that emerald is your culprit..