Something killed my blue mandarin

[Trish300]

We got a new blue mandarin yesterday. Came home today and something had eaten the head of my poor fish. Only his skull and body were left. This is what I had in my tank.
100 gal tank
1 Foxface Rabbit
2 Cardinals
2 Firefish
1 Scooter Blenny
1 Arrowhead Crab
1 Cleaner Shrimp
1 pipefish
1 feather duster
1 emerald crab
various hermit crabs and snails

I can't imagine what killed it. In all my research it says nothing about these fish being a problem with a blue mandarin. Anyone have any ideas. I want another one but don't want to get one until I find out the problem.

Thanks
Trish

 

[Mrc8858]

Possibly the arrow crab but honestly the most likely scenario is that when you bought the mandarin it was already effected by malnutrition and the shock of the move was the straw that broke the camel's back.. after that he just becomes scraps for your crabs which they won't let that much meat go to waste...

 

[Kribensis_2004]

I would also put my money in with the arrow head, they tend too scavenge what they need, but as they grow they tend too get more aggressive as they age. With that being said, he probably just saw the fish sleeping and just jumped on him and ate him.

 

[Cjsanders757]

Could've been the emerald as well. Mine killed my royal gramma.

 

[bettaowner]

Arrow crabs are really aggressive. I think the emerald would only attack at night.

 

[Tkh]

Are crabs just not a good idea if designing a peaceful reef / invert tank? Love crabs, but not if they decide to kill my other creatures...

 

[Trish300]

Wow, I have never seen the arrowhead crab be agreesive. I have seen him poke at some fish but not agreesively. I really want to get another one, but I will ask more questions as to if they have been trained to eat other than copepods. When we put him in the tank I immediately added copepods because I had researched and knew how difficult it was to feed them. Maybe he was already starving, he didn't look that thin but sometimes it is hard to tell. My arrowhead crab may have to go. Thanks for all your replies, much appreciated.

Trish

 

[Kribensis_2004]

Emerald crabs are ok with enough room, they do okay in reefs as they are more savaging herbivores. But like all crabs they do have a tendency too eat dead fish if they find it. But like the others are saying i would still put my money on the arrow crab, because of there size and ability to be aggressive and hunt for food.

 

[bettaowner]

Emerald crabs are scavengers so unless the fish was near death, the arrow crab is most likely the culprit. Upon looking at your stock list again, I think your scooter dragonnet may have eaten most of the food your mandarin was after.