Corallinus Rabbitfish dead overnight. Any ideas?

Mr_Knightley · Sep 6, 2021

I found my Corallinus rabbitfish dead this morning next to an Acanthastrea Hemphrichii. His belly was full and he had eaten last night. I've attached pictures of the deceased fish for possible ID of the cause. The only abnormal things about it are the strange white patches on the sides.
A bit of info about the tank. It houses a large condylactis anemone upstream of where I found the corpse. I'm currently struggling with red flatworms and bryopsis, which the rabbitfish has been eating. My alk has been a little low at 6-7 and my nitrates are between 10-15 ppm, so nothing out of the ordinary. Again the fish has been acting completely normal over the past few days so I don't know what to think.
Another thing I should mention is that the tank is situated in a busy basement, and occasionally the lights are turned on past midnight by siblings who need to get around. I plan to get a curtain hang in front of the tank at night.

Thanks so much and God bless!

i cant think · Sep 6, 2021

Did you see any bullying when he was alive?
I can’t figure out what the white blotches are but it may just be from where it’s began to lose colour

Mr_Knightley · Sep 6, 2021

i cant think said:
Did you see any bullying when he was alive?
I can’t figure out what the white blotches are but it may just be from where it’s began to lose colour

He's lived quite peacefully with a group of tangs for the past 3 or 4 months, and no new behavior was witnessed before last night.

i cant think · Sep 6, 2021

Mr_Knightley said:
He's lived quite peacefully with a group of tangs for the past 3 or 4 months, and no new behavior was witnessed before last night.

What was the new behaviour like?

I read that wrong, sorry!

JumboShrimp · Sep 6, 2021

That really stinks. I looked online-- those are quite beautiful fish.

Mr_Knightley · Sep 6, 2021

i cant think said:
What was the new behaviour like?

I think you misunderstood- I said there was no new behavior, so it had been acting perfectly normally before it died. Sorry for lack of clarity.
@Jay Hemdal could you input your thoughts?

i cant think · Sep 6, 2021

Mr_Knightley said:
I think you misunderstood- I said there was no new behavior, so it had been acting perfectly normally before it died. Sorry for lack of clarity.
@Jay Hemdal could you input your thoughts?

I can’t think of what it could be but it looks like flukes on a small fish

Jay Hemdal · Sep 6, 2021

Mr_Knightley said:
I think you misunderstood- I said there was no new behavior, so it had been acting perfectly normally before it died. Sorry for lack of clarity.
@Jay Hemdal could you input your thoughts?

I'm not seeing anything obvious - sorry!

The pale patches on the belly are most likely post-mortem artifacts. In the third photo down, the caudal fin looks frayed - could some CUC munched on it after it died, or did it have fin damage prior to death?
Have you added any chemicals to battle the flatworms or Bryopsis?
Fish can sometimes go into shock if the lights are flipped on. If they then run into a tank wall or a rock, they can theoretically die, but it is pretty rare.

Jay

Mr_Knightley · Sep 6, 2021

Jay Hemdal said:
I'm not seeing anything obvious - sorry!

The pale patches on the belly are most likely post-mortem artifacts. In the third photo down, the caudal fin looks frayed - could some CUC munched on it after it died, or did it have fin damage prior to death?
Have you added any chemicals to battle the flatworms or Bryopsis?
Fish can sometimes go into shock if the lights are flipped on. If they then run into a tank wall or a rock, they can theoretically die, but it is pretty rare.

Jay

Thanks.

There wasn't any previous damage that I could see, so it was probably CUC after the fact. I haven't added any chemicals to the tank at all. I guess this was just one of those rare cases ;Facepalm Thank you all for the input, even if it was fruitless. God bless you guys!