Lionfish gone blind

[Caro]

Hi,
My lionfish has gone blind. He at first became stressed out swimming into the live rock and sides of the tank. After a week he has felt his way around the tank to know where the rocks are and how long the tank is. He hasnt eaten for 3 weeks now. I try force feeding him white bait and green prawn meat but he coughs the food back out. He is shedding his cuticle once a week. My tank is 300 litres. Tank has been established for 2 years. Have had the lionfish for 18 months - 25 cm long. Nitrate is 80, Nitrite is 0, & Ammonium is 0. Phosphate is 4 after the last test. This is usually 0 and this is the first time its been above 0. PH is 8. Since the last test have done 30% water change. Previously we do a 25% water change every 3 weeks. There is no cloudiness in his eyes. No opaque covering over the lens or sign of a catarat. I also have a longhorn cow fish. Would the cow fish be secretting any poison? Our domino damsel, and blue ribbon eel appear healthy and fine. Also have a sea urchen in the tank. His feeding history - was feed fresh water fish for the first 3 months but havent feed him this since. Any thoughts on getting him to eat & the cause of his blindness? And can this be cured?
Many thanks, ) Caro

 

[waterfaller1]

I am not certain what the cause is..but you need to get the nitrate and phosphate down. Phosphate is equal to ammonia. A phosphate reading of 4 is very high...and nitrates should never be more than 20. If I am correct in my conversion this tank is 80 gallons...too small for a cowfish...and honestly for a full size lion as well. Cowfish do put out a toxin when stressed. Those parameters would stress a fish. Could the damsel also be harassing the other fish?

 

[Patchy]

i say stress, he needs more room... tank is almost 90g that will proberly mean its 14inches wide IMO thats not enough for a 25cm fish. but if his sight is really damaged he may never regain...you sure his not just listless? i have seen a lion that had its eyes taken out by a trigger that could navigate a tank perfectlly

 

[FMarini]

its most likely either a dietary insufficiency or what started out as a subclinical bacterial infection that went unnoticed and attacked its optic nerve. Unfortunately i have seen this before in harlequin tusks and other predatory fish. I doubt it can be reversed.
problem is he won't feed. If he were feeding and blind that would be no problem. Try this, lightily rub & bump the fish flesh on his nose, see if he can smell it, he might try to engulf it. You might get lucky and just have to "hand feed" this fish for the rest of its life

 

[Caro]

Thanks for everyone's replies. Its now getting on 4 weeks with the lion not getting. Have tried tapping and placing the food on the lion's nose but still not interested. This is not looking good. I'm amazed how long the fish has gone without food!!! Have read that lighting can be a problem as well. Is this true? I have one light on during the day 9-5 then uv and 2nd normal light on for another 5hrs then all lights off past 10 pm. Will keep trying to get the phosphate and nitrate down..

Caro

 

[stykthyn]

unless he was under metal halides I wouldnt think the lighting caused this, I did notice that you have a cowfish. They are notorious for emitting toxins in the water. this is a possible cause. are you using activated carbon? this will remove any of the toxins that the cowfish will release.