Naso tang stopped eating

[LobsterOfJustice]

Hey all,

I have a large Naso in my 180, probably about 7". Within the past week he has stopped eating. I noticed on friday night, but by the time I noticed he wasn't eating I also noticed you could see his spine and his stomach was pinched. So I assume he hadn't been eating for at least a few days by the time I noticed. I havent been watching the tank very closely the past few weeks and he was always a good eater so I overlooked it I guess. He usually goes at nori with gusto as well as anything else (mysis krill etc). He is the largest fish in the tank, the only other large fish are a sailfin tang (which is more agressive than him but half the size) and a harlequin tusk. I never see any aggression towards him from the other fish. The past two days I have been putting nori on two separate clips just in case the sailfin was keeping him from eating, but it didnt work. I also tried soaking nori in garlic yesterday. He is less active and shows no interest in food. Some time last week I did a large water change to lower nitrates which dropped the temperature in the tank by several degrees, but temp was back to normal by the next morning and all the other fish and inverts seem fine. Other than that, I cant think of any recent changes.

Any ideas? Why would he stop eating after over a year of being a pig? What could I offer that would be particularly enticing? Anyone had this happen before?

Thanks

 

[Amazon4]

How long have you had him? First impression is that it's an internal parasite. At this point QT with a course of prazipro may be your only option since he's stopped eating and all ready dropped that much weight. Prazi can be tough on a fish, but if it is an internal parasite, I think it's the only way to get rid of it (he won't eat medicated pellets now).

Normally you would want to treat prazi to a strong healthy fish in QT. Unfortunately he's got an uphill battle, but it's not impossible. Keep the water quality excellent and well oxygenated.

Naso's are also known to stop eating, just because. Some times they come around, some times they don't. But the rapid weight loss sounds like parasites.

Good luck with him - they're an awesome fish.

ETA: sorry, you said a year (reading is fundamental!) Could be a hunger strike...but it's a tough call.

 

[LobsterOfJustice]

Yeah, I've had him for at least a year. The previous owner had him for a year or two and raised him up from a small size. I actually treated the tank over the summer with two treatments of prazipro, but I have added fish since then (but you'd think they would be showing earlier/worse than the naso if that was the case, no?). Also I can see parasites causing weight loss, but would that affect appetite?

I didn't know this was a thing with nasos.

 

[Amazon4]

If he's been treated before, then sounds more like a hunger strike. There are threads on here of folks that have gone through similar things.

I'm sure folks with more experience with them will chime in.

Don't you wish you could just get it through their fishy minds that they need to eat!?