Smaller Fish Disappearing from Tank

[jaspercrane]

I have had all 6 of my smaller fish die over the past month or so, including 2 wrasse (3"-4"), 2 anthias (2"-3"), and 2 angels (1"-2"). Two of the 6 were found floating after missing for a while, and the other 4 never re-appeared...

This is my first aquarium, and it is ~650 gal. Current stock includes 7 tangs, 1 squirrel fish, a porcupine puffer (~5"), a rabbitfish, a harl. tusk, and an ~18" dragon eel. My best guess is the puffer or dragon eel is having snacks. Can anyone help me solve this mystery?!

Thanks!

 

[P-Dub]

That's definitely a possibility that your puffer and your eel are thinning the herd. The ones you found floating, did you examine them? Were there any outward signs of trauma? You may also have a rogue pistol or mantis shrimp of some sort in the tank. I have lost a few fish myself to one. I have not seen the crafty little murderer but I do hear him...

 

[alanbetiger]

If you haven't already, check your overflows and any drain pipes. But yeah most likely the puffer.

 

[Amps Reef Life]

First of all, I want to say congratulations on your first aquarium and it's a 650 gallon that's awesome. I would put my money on the eel. I two dwarf hawaiian eels in my tank and they stay small but will eat little fish. This is common for any eel. I simply don't keep tiny fish in my tank.

That's definitely a possibility that your puffer and your eel are thinning the herd. The ones you found floating, did you examine them? Were there any outward signs of trauma? You may also have a rogue pistol or mantis shrimp of some sort in the tank. I have lost a few fish myself to one. I have not seen the crafty little murderer but I do hear him...

Also this. You could have a rogue shrimp. You didn't say if you started with dry or live rock. Typically these shrimp can come in on live rock.

 

[lion king]

The type and size of the missing fish does point to the dragon eel. As stated above, did the other 2 have any trauma and were they the larger or broader body of the 6. Another note be very, very careful introducing any new fish with the dragon eel. Make very sure he clearly sees you introducing them and be prepared to break his attention if necessary, make sure he knows you are not introducing food. Overall the dragon eel is usually not that aggressive, but they will take fish down when being introduced to the tank and smaller fish, so slender bodied smaller fish may always be at risk.

 

[Amps Reef Life]

The type and size of the missing fish does point to the dragon eel. As stated above, did the other 2 have any trauma and were they the larger or broader body of the 6. Another note be very, very careful introducing any new fish with the dragon eel. Make very sure he clearly sees you introducing them and be prepared to break his attention if necessary, make sure he knows you are not introducing food. Overall the dragon eel is usually not that aggressive, but they will take fish down when being introduced to the tank and smaller fish, so slender bodied smaller fish may always be at risk.

You are correct. I was mistaken after reading this over again it does not sound like the eel. The fish wouldn't be dead floating they would be gone.

 

[4FordFamily]

Puffers can be ruthless but if you’re finding bodies I imagine something else is at play, possibly disease.

Any symptoms?

 

[jaspercrane]

Cool thanks everybody for the help. Sounds like it is definitely the puffer or eel, but we may never know unless we catch one in the act (or install a webcam). My fish guy came by yesterday with 3 more anthias, 5 chromis and a wrasse, so I guess we may know more soon. I told him not to put them in with all the small fish deaths recently, but he wasn't concerned... So far they are all still kicking! Thanks again.