Coral Cat Shark Feeding

[katie_b0206]

Hello everyone, I’ve a coral cat shark in our 175 gallon, and recently I’ve noticed that his mouth doesn’t shut all the way and it looks like his tongue is very swollen. From what I’ve researched now this is common when they aren’t getting the right supplements. He currently is 16 inches long and lives with a small stingray, a golden butterfly, and a blonde naso. He eats krill every day with some silversides once every other week or so but now I’ve found out I need to vary it more. I’ve seen that people use Mazuri supplements to get it under control, does this work? Any tips help please. Also please be kind as I am a minor.

 

[Jay Hemdal Verified Community Expert]

Hello everyone, I’ve a coral cat shark in our 175 gallon, and recently I’ve noticed that his mouth doesn’t shut all the way and it looks like his tongue is very swollen. From what I’ve researched now this is common when they aren’t getting the right supplements. He currently is 16 inches long and lives with a small stingray, a golden butterfly, and a blonde naso. He eats krill every day with some silversides once every other week or so but now I’ve found out I need to vary it more. I’ve seen that people use Mazuri supplements to get it under control, does this work? Any tips help please. Also please be kind as I am a minor.

Can you post a picture?
It does sound like goiter, that is pretty common in captive sharks. It is due to a lack of iodine or the presence of a compound that interferes with iodine uptake. The small Mazuri shark vitamins will fix it as long as the shark hasn’t had the issue too long (like more than 4 to 6 months).
Jay

 

[katie_b0206]

Can you post a picture?
It does sound like goiter, that is pretty common in captive sharks. It is due to a lack of iodine or the presence of a compound that interferes with iodine uptake. The small Mazuri shark vitamins will fix it as long as the shark hasn’t had the issue too long (like more than 4 to 6 months).
Jay

Sure, I only noticed it a month ago. Picture attached. This is the best I have now, I will try to get a better one tomorrow, they just ate so he is ready for bed.

 

[Jay Hemdal Verified Community Expert]

Sure, I only noticed it a month ago. Picture attached. This is the best I have now, I will try to get a better one tomorrow, they just ate so he is ready for bed.

Sorry, to see goiter, we need a clear view of the lower jaw, below the eye.
Jay

 

[Aspect]

If you've only been feeding krill and silversides then it would be a miracle if it didn't have goiter.

 

[Aspect]

There's also some new research going around that prolonged high nitrates levels >40 will cause goiter in elasmobranch.

 

[Jay Hemdal Verified Community Expert]

There's also some new research going around that prolonged high nitrates levels >40 will cause goiter in elasmobranch.

It actually is a pretty old idea. I had heard that back in the late 1980's Here is a study from 2011:

Nitrate-induced goiter in captive whitespotted bamboo sharks Chilosryllium plagiosum - PubMed

Elasmobranch susceptibility to goiter formation in captive environments has been well documented. Until recently, most public aquariums operated under the belief that the etiology of goiter in elasmobranchs was nutritional and specifically caused by insufficient dietary iodine. Recent studies...

pubmed.ncbi.nlm.nih.gov

Goitrogenic compounds are tricky to work with - do they simply reduce iodine to iodide? Do they hamper iodine uptake? Do they affect the thyroid directly? Do they work synergistically with other compounds?

What I've found is adding iodide to the water is useless. Adding iodine is difficult. Thyroxine doesn't seem to help, but iodide added to the food does work at a dose of 2.5 mg per pound of animal weight weekly. In some case though, the goiter is permanent.

Jay

 

[katie_b0206]

If you've only been feeding krill and silversides then it would be a miracle if it didn't have goiter.

I was told by the place I got him that that was what I should feed. I’m now realizing that this was wrong and trying to fix it.

 

[katie_b0206]

It actually is a pretty old idea. I had heard that back in the late 1980's Here is a study from 2011:

Nitrate-induced goiter in captive whitespotted bamboo sharks Chilosryllium plagiosum - PubMed

Elasmobranch susceptibility to goiter formation in captive environments has been well documented. Until recently, most public aquariums operated under the belief that the etiology of goiter in elasmobranchs was nutritional and specifically caused by insufficient dietary iodine. Recent studies...

pubmed.ncbi.nlm.nih.gov

Goitrogenic compounds are tricky to work with - do they simply reduce iodine to iodide? Do they hamper iodine uptake? Do they affect the thyroid directly? Do they work synergistically with other compounds?

What I've found is adding iodide to the water is useless. Adding iodine is difficult. Thyroxine doesn't seem to help, but iodide added to the food does work at a dose of 2.5 mg per pound of animal weight weekly. In some case though, the goiter is permanent.

Jay

Ok, thanks, I will get iodine this week

 

[Aspect]

Ok, thanks, I will get iodine this week

Get Mazuri shark vitamins, the smaller vitamins for "baby sharks"

 

[katie_b0206]

Sorry, to see goiter, we need a clear view of the lower jaw, below the eye.
Jay

 

[Aspect]

Yeah looks like goiter. Get started on the Mazuri vitamins asap. Also what size is the shark?

 

[katie_b0206]

Yeah looks like goiter. Get started on the Mazuri vitamins asap. Also what size is the shark?

Ok I’ll order them tomorrow. He is 16” long, growing very fast, only last month he was 14”