[dwhite]

I have been a hoobbyist for 8 years. My newest tank is 180 FOWLR with 20 gallon sump setup for a liitle over a year. I have had this Violiton lionfish for 7 months, he is about 9 in long. all of a sudden for the past 4 to 5 weeks he cannot open his mouth to eat. He eagerly tries but when he goes to strike at food his mouth will not open. I have also tried live ghost shrimp at night, he goes for it but nothing happens. I really do not want to loose this fish. I can't believe he is still alive. He still swims around still with energy and is very well mannered, doesn't bother tankmates or myself when cleaning. I have done web research and have ask everyone locally and have even tried to talk with public aquariums, no one can figure it out.....Can anyone HELP??????

[leebca]

WELCOME TO REEFLAND!

On very rare occasions, a fish's jaw can lock. Most of the time this is in the open position. Due to plates in the jaw, the fish can find that a displaced plate can prevent the jaw from closing.

I've only heard of one time before your post where a jaw was apparently locked shut. It was a swelling of the tissues in the 'joint' area of the jaw. The jaw muscles for marine fishes are very strong to close the mouth (like a crocodile) and very weak to open the mouth (like a crocodile). (This is why 'wrestling' a crocodile isn't that big of a problem because it is easy to keep their jaws shut. Muscles that open their jaws are very weak.)

Speculating of course, but there may be an internal infection, which was the diagnosis of the above fish. Who knows. But on that outside chance, the procedure would be to remove the fish to a hospital tank and (maintaining excellent water quality) treat with a double dose of Maracyn Two for Saltwater fishes for a 5-day treatment.

Beyond the above, I can offer nothing else.

[dwhite]

Thank you for responding.......I have treated with Maracyn twice since this happened. I did find on web where a fish can develop a goiter in their throat from lack of Iodine, and only eating certain types of frozen foods, but I feed a variety and have been dosing Iodine every week. There is no visual swelling in the throat though. Have you ever heard of a goiter possiblly reversing and shrinking?

[leebca]

To put the matter of iodine short and sweetly -- the artificial salt used to make up saltwater has an excess of iodine than that found in natural sea water (NSW). So adding iodine is unnecessary. In essence, artificial salts already have an excess of iodine. Adding iodine shoots iodine levels to extraordinary highs which I do not recommend.

If you are using NSW, then an iodine addition would put that element in high concentration over what is normal in nature. Unless you monitor its concentration and understand what you are doing, then I would not recommend using an iodine additive for marine aquariums that use NSW water changes.

Lastly the foods you feed have all the iodine that your fish needs.

Marine fish goiters are rare, to say the least. Only diagnosed by postmortem when the goiter is small. When over-sized, it is obvious from external examination.

From what I understand of this kind of malady, an iodine treatment doesn't reverse it. Surgery is the only course I've heard about.