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FAQs about Shark, Ray Nutritional Disease/Health  

FAQs on: Shark Diseases 1, Shark Disease/Health 2, Shark Health 3, Shark Health 4, Sharks/Rays & Crypt,
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NOT Goldfish, nor solely silversides, OR squid, krill, bivalves, octopus alone... Best to buy small, whole marine fishes... defrost

NEED vitamin supplementation, additions of iodide-ate to foods, the water.

SEE/Read Marco's article on Thiaminase: Thiaminase and It's Role In Predatory Pet-fish (& Other Piscivores) Nutrition,

Sharks and Rays in Aquariums
Gaining an understanding of how to keep these fishes in captive saltwater systems   

New Print and eBook on Amazon

by Robert (Bob) Fenner
Bigger PIX:
The images in this table are linked to large (desktop size) copies. Click on "framed" images to go to the larger size.


Banded cat sharks... health, nutr....       3/25/19
I have two banded cat sharks living in a 150 grow out tank until my 1000 gallon tank is finished for them. My female is extremely healthy, ten inches and had good, vibrant color. But my male has really Grey coloration, hasn't grown as much (only seven inches) and seems to have something growing on his eyes.
<Sometimes there are color variations in the same shark species>
They are BOTH eating healthy on vitamin soaked krill silversides and clams.
<This diet must be enlarged, silversides have poor nutritional value, try squid and shrimp instead. Are you familiar with Mazuri Shark & Ray formula?, it is a well-balanced food source for captive Elasmobranchs.>
Ammonia nitrite are both 0, nitrate is 20ppm pH 8.3 Carbonite<Carbonate> hardness 8 and salinity <Specific Gravity> 1.025. I'm  really worried about my male and was wondering what was going on, especially with his eyes, and if I could do anything to help him.
< Can you send us a pic?, is this unilateral or in both eyes? Wil>

Re: Banded cat sharks      3/27/19
I've had them since January. The tank has been running since June. The only other tank mates is a Naso Rank <Tang> and a volitans. Neither of wich <which> bother the sharks.
<I suggest you to do frequent 10% water changes and add a good vitamin supplement directly to the food to improve shark's health; also do read where you were referred to. Wil.>
Re: Banded cat sharks      3/27/19

I do at least a 20% water change every week and soak their food in vitamins. I'll also widen their diet and hopefully that'll help
<Me too, keep us posted. Wil.>

Banded cat shark 3 week old acting strange. Hlth.; nutr.           6/13/16
Hi WWM crew,
I have a banded cat shark (Chiloscyllium punctatum) that I had hatched from an egg. I haven’t seen it totally eat yet but it has snapped at my grabber when I put squid in front of its face a few times and the squid seems to go missing so you’d assume it had eaten. This only happened once or twice though and I have tried to feed it prawns, scallop, squid, mussels and krill.
<Do please read on WWM re Thiaminase poisoning/B avitaminoses. The diet needs to be enlarged, altered (whole non-fatty small fish esp. added)... plus vitamin supplemented. Are you familiar w/ the Mazuri line? Search on WWM Re
It has never really shown any interest even if I put the food in its face. It likes to hide in the caves and is quite inactive a lot of the time. It breathes every second or so at a healthy rate, it has no cuts or abrasions or redness and looks to be healthy. it is currently about 8 inches.
I have tried soaking the food in Selcon and garlic guard, the other fish eat it with no problems. (other fish currently only a regal tang, fireball angel and a leopard wrasse)
Tank is 200 gal, 25 degrees Celsius usually, no nitrates or phosphates
<How are these rendered zip? This could be an issue... chemical filtrants
or ammonia (obviously).
I found the shark upside down today and thought it was dead, I flipped him over and he moved off a bit, was still breathing but seemed sort of asleep. He has been acting sort of ‘asleep’ in the same area of the tank at the same time of evening 2 or 3 days in a row now. He hides in the cave during the day and every time I check back to the tank he is in one of his 3 usual spots. He doesn’t exhibit this worrying behaviour during the day, just for a few hours on an evening around 8-9pm for the last 2-3 days.

I am baffled by this behaviour. My priority concern is getting him to eat now, my next concern is why would he be upside down and not wake up or move even though he was breathing steadily whilst upside down! do they sleep?
I read they are nocturnal.
I have tried fooding a plethora of foods at different times of day.
How would I test if this was a ‘grounding issue’?
<Gone over on WWM>
I live in England and don’t know if plugs are different in the US but aren’t all plugs grounded? our plugs are all “earthed”
<Mmm; your other livestock has not been mal-affected; so I discount induced current issues>
I have tried to include all the info you may need here to rule things out so sorry for the length of this email.
<Let's review: You're to read re young shark nutrition, Mazuri.com vitamins for sharks, the mis-use of HPO4 and NO3 removing methods... on WWM. Write me back if you have further questions, concerns.
Bob Fenner>

Coral Cat shark swollen tongue or something else in its throat.        3/3/15
I have a 15" Coral Cat shark and she's having trouble eating. There is a large pink bubble like body part in her throat. It looks like her tongue is swollen to the the point where she cannot close her mouth. I've been on several forums and websites and a lot of them say it is likely that it is an iodine deficiency.
<Yes; a goiter... not iodine, but iodide-ate>
Unfortunately there has been no studies on this issue.
<.... wrong>

Do you have any other ideas on what this problem is? And how to fix it before it's too late. Any answers will be appreciated.
<Search "shark goiter" on WWM and read. Bob Fenner>
Re: re: Coral Cat shark swollen tongue or something else in its throat.        3/3/15

did you see the pictures? are you sure that its a goiter?
<Did see the pix; not sure. Do you feed Mazuri? BobF>
Re: re: Coral Cat shark swollen tongue or something else in its throat.        3/3/15

she gets ghost shrimp, live blue green Chromis, live craw dads, thawed silver sides, thawed shrimp and occasionally a hermit crab or snail that she sucks out of shells she finds in her tank. We do not give her Mazuri.
<Ahh; I would. B>

3 year old banded cat shark sick... hlth., likely env. and nutritional    2/19/13
I've owned this cat shark for a little over a year, she's always been active and healthy. She's kept in a 300gal tank (84/30/24). We run two can filters, a 450gal skimmer, small sump, 2 power heads. Water parameters are 1.026sg, 76 degrees, 8.3ph, 0ammo/nitrite and our nitrates are usually in the 80ppm range
<Much too high
... and symptomatic/common for most all shark losses in captivity: the ill-effects of exposure to concentrated, accumulated metabolites>
 (I did recently upgrade to that larger 450gal skimmer and also added a bio pellet reactor to help with the nitrates)...
<I'd do more than this. See WWM re methods of NO3 control>
 I know the nitrates are high but I've had people say its not too big of a deal in a tank that large.
<Is a big deal>
Shark has seemed fine in the listed conditions.
However, 6 days ago she stopped swimming
and just lays in one spot, she'll wiggle a little to scratch her belly and before some major water changes (50% then 30%) she was swimming in her side for a brief moment, presumably to scratch her gills. After the 50% water change she finally ate and swam around a bit. I thought we were in the clear, that was 4 days ago. But she went back to just laying on the sand. I haven't actually seen her swim since she ate 4 days ago. I'm not sure what to go, or what caused this, but here's a little history of some out of the norm things from a few days before her signs of illness...
About 5 days prior, I did a large (40%) water change. After, I realized that my RODI system was putting out about 86ppm if TDS. So it's possible there was something in the water that is bothering her.
<Doubtful... there's more TDS added via salt and foods>
In a state of panic (a couple days later when the shark was looking sick), I dosed the tank with Prime just in case it was water pollutants or metals.
<Of no use here>
Also, just a day or two before the symptoms, I added a bio pellet reactor which made the water cloudy from a bacteria bloom (every thing I've read says that's normal and harmless, but I'm not convinced).
<You should be>
Also, I had just bought a fish from a local chain pet store (against my better judgment), so in thinking possible disease introduced?
Lastly, I put a capful of Iodide in the sharks food (per my local fish stores direction) and let it soak in. I do this about once a month just to make sure she doesn't get gout. I feed her mostly frozen silversides and a little krill. Occasionally some thawed squid cubes.
<See WWM re shark feeding, Mazuri.com foods, supplements>

Her breathing is normal. Eyes and belly look normal. Everything else in the tank looks fine. Well, I do have a Cortez ray that I've had for over 2 years that occasionally shows a red line on her belly.
<This is telling as well... see my initial comment... the skimmer may help... do you use Ozone, have a RedOx measuring tool? Very useful for determining real life-sustaining capacity of captive systems. See WWM re these as well>
We thought it was a scratch, but maybe it's some sign of a parasite?  She is always super active and has the appetite of a 15 year old boy.
Any help would be appreciated. Thanks!!!
<Read and write back if you have questions, further concerns. Bob Fenner> 
Re: 3 year old banded car shark sick     2/20/13

Here's a video of her behavior, also she's covered in sand, exhaling sand and her belly is bloated and sort of hard; she won't swim at all.  Anything I can or should do immediately to relieve her of pain or improve her condition?  Is it possible that she's just about to lay an egg (she's probably about 3.5 years old)?
<Just patience and hope. BobF>

Problem with nurse sharks Cyprus  7/19/06 Mr. Fenner <Nikos> I am a very huts fun of you and your side. <Ah, good> Daily I am visiting the wetwebmedia but this is the first time that I am contact with You. I have a problem and I think you cine help me. I have two Nurse sharks and I think they have thyroids, both of them have golf ball under their mouth. <Yes... likely an iodine/iodide deficiency> The first shark is 60 cm total length and the second is 30 cm total length. I feed them daily fresh fish or crabs because I am a fisherman. I hope you can help me. Nikos Koutsoloukas Cyprus <I have visited your island (in 1996 with the Hash House Harriers). Please look into supplementing these sharks diets with Iodine (the best, most likely available to you is Lugol's Solution). Please read here re: http://www.google.com/custom?domains=www.WetWebMedia.com&q=shark+goiter&sitesearch=www.WetWebMedia.com&client=pub-4522959445250520&forid=1&ie=ISO-8859-1&oe=ISO-8859-1&cof=GALT%3A%23008000%3BGL%3A1%3BDIV%3A%23336699%3BVLC%3A663399%3BAH%3Acenter%3BBGC%3A99C9FF%3BLBGC%3A336699%3BALC%3A0000FF%3BLC%3A0000FF%3BT%3A000000%3BGFNT%3A0000FF%3BGIMP%3A0000FF%3BFORID%3A1%3B&hl=en Bob Fenner>

Bamboo shark won't eat... Nutritional deficiency most likely  9/18/06 Crew at WWM, <HC> I have a Bamboo shark I hatched from an egg about 2 years ago. The shark is about 23" in length which most of the growth occurred over the past year. I do water changes every week to every other week no less than 10% of the tank which is a 125 gal. The water is from tap which goes through a R.O. filtration unit plus a D.I. unit. Where I live the city water is pretty bad with copper and other minerals. Up to about a week to 10 days ago my shark had been eating every day (silversides) and some Brine shrimp which falls to the bottom that is fed to the fellow tank mates. The tank mates include: 1-Regal tang, 1- Niger Trigger, 4-small yellow tail blue Damsel, 2-large black Damsel, 2-Pencil Urchins a few small hermit crabs & sand sifter stars. When I feed and allow the Silversides to fall to the bottom my shark is not interested nor acknowledges the food. I have tried Mysid shrimp which was the sharks staple up to about a length of 12" along with Krill. I had noticed about 4 days ago the shark had twitched and rubbed on some of the live rocks in the tank. (no ich is present) when I cleaned a pre-filter to the wet/dry filter  there was a lot of Amphipods and the sump filters have a lot of very small Feather duster babies, not sure if these critters larva are causing the eating problem. <Highly unlikely> The water condition in the tank is as follows: Temp. 78 degrees Ammonia- 0.1 Nitrate-30 <A bit high... would keep under ten ppm> Nitrite-0 Calcium-540 <Way too high... would keep under 450 ppm> Phosphate-4.5 <Again... should be less than 1.0 ppm> Iron-0 Alkalinity-70 P.H.-7.9-8.0 <A bit low...> Salinity-1.023-1.024 I have attached a couple of photo's of the shark, I have not noticed any weight loss but the not eating is concerning me. If you have some advise please help. <I do... you don't mention the use of vitamins, supplementation including iodine/ide... This is likely the primary problem here... Deficiency syndrome. Please read here: http://www.wetwebmedia.com/sharkfeedingfaqs.htm and the linked files above... At this point, you may have to force feed this specimen, or have someone inject it... to have it resume feeding behavior on its own. Bob Fenner>

Goiter on Elasmo.   2/11/07 About a month ago, our bamboo shark began to have a small lump form under his mouth.  It has continued to grow and is now about the size of a ping pong ball.  About a week ago, he quit eating (probably due to the size of the lump).  At first we thought it was a tumor, but after reading some of the entries we are thinking it might be a goiter. <Agreed.> We can't find many pictures of sharks with goiters to confirm our diagnosis, so we're sending you some pictures of our shark and maybe you can confirm if that is a goiter. <Appears to be so.> Thanks for all of your help and information, <Begin dosing iodine to the water, and soaking the animals food in such as well. To help diagnose, what size/age is the animal...what size tank? Water parameters and diet would be helpful as well, also search WWM re: elasmobranch care.> Katie
<Adam J.>

Bamboo Shark Tumor Growth, Mixing Wobbies and Leopards... Bob, <Amy> I hope you can help me.  We have a 2,000 gallon aquarium with a puffer, a bamboo shark, a wobbegong (sp?), a leopard shark, an eel, a few tangs and a butterfly...    We had many other small fish but they have succumbed to shark and eel snacks as well as a parasite....   Our bamboo has a large growth on his ventral side right under his mouth.  His coloring has faded and he is now unable to open his mouth to eat. <Likely an iodine/ide deficiency syndrome... please read on WetWebMedia.com re sharks, rays and these tumors. Actually, easily rectified if not gone too far>   He tries and tries to get the pieces of food (we have cut them smaller and smaller) and he just can't seem to get them.  I was reading some of the earlier posts and saw the references to goiter. <Ahh, yes> Could this be what it is, he seemed healthy until about a month and a half ago when the growth appeared.  I am also wondering if the two new sharks (the leopard and the wobbegong) were a smart idea or not. <Mmm, no... the Leopard is coldwater and the Wobbie... is an all out eating machine> The wobbegong has had one of the eels for a snack already and attacked the puffer (I believe it was because puffy did not realize he was covering up a piece of food and the wobbegong was trying to get it). <Mmm, actually... the carpet shark will inhale most anything digestible...>   I am mostly concerned about the bamboo shark though.  Is there anything we can do?  I really don't want to see him suffer, and if we can help him recover I would like to do that. Thank you so much! Amy Tezak <You can force-feed this specimen with a bolus (food capsule) including iodide... or inject/have it injected with same... Likely will have to be done a few times... easier to relocate it in the meanwhile to a smaller system... and do something (choice) between keeping it and the Wobby... as the latter will consume the former in time. Bob Fenner>
Re: Bamboo Shark  Growth
Bob, <Amy> Thanks for your response yesterday.  I spoke to the gentleman who generally takes care of our aquarium and found out that they tried to drain the growth last weekend.  I did not know this.  Apparently he used a syringe and drained it, there was mostly blood but some filmy yellowish fluid (puss I assume) as well.  Would this be consistent with goiter?  He also said that our nitrate levels have been at or under 20ppm (thus I do not think we have had elevated nitrates).  Thank you again for your time and help. Amy Tezak <... I used to "do" necropsies of cartilaginous fishes as an itinerant "fish vet." of sorts... for public aquariums... mostly ones faced with large (numbers) of imminent livestock losses... I don't recall ever seeing, reading, hearing about such a procedure as you describe for evaluation, treatment of tumorous growths in sharks and rays. Would you have the folks involved write me here re this? Twenty ppm. of nitrate might play some role here... but goiter in these fishes is almost always related to thyroid/Chromaffin tissue and iodide insufficiency. Bob Fenner>
Re: Bamboo Shark  Growth
Bob, I can ask if he will contact you.  However, I will say, I do not trust him fully. <... What?> That is why I am researching on my own.  Our wobbegong; which looks like every photo I have ever seen of one, he says he has never seen one that looked like that.  Also, he has said some other things that lead me to believe he does not have a great knowledge of, at least, the cartilaginous fishes. <You should both take a look on fishbase.org and at the very least identify this shark to species... look at their listings for the family Orectolobidae> He mentioned that he believes it will be too stressful to catch the shark to feed it, that it may do more harm than good..... I feel, if he is not eating, how can it be more harm?  Sharks are fairly resilient are they not?   <... If you do not get the food, iodide into the animal it will surely perish> As far as the feeding goes, from what I have been reading we should blend up some of the scallops, shrimp etc and syringe feed him.  As far as the iodide, I have not seen anywhere as to how much to give him.  I assume I would add it to the food. <Yes... READ over the FAQs files archived on WWM, and on to the Net in general. NOW> Thank you again for your time and information. Amy <Amy, help your livestock and yourself. Bob Fenner>

Nurse Shark not eating and stressed (Big Surprise) - 2/10/05 I know a nurse shark is not good for the home aquarist but I couldn't let him stay in the small tank at the fish store. He had been there a week.  <Well, now he can not do well in your tank too.> Anyways, I have had him for 4 months and he has been doing really good. Was full of life and personality. Actually was a great entertainment to watch. Would come to meet you if you walked up to the tank, do push ups with his front fins. Been a great addition to the house. Starting last Tuesday I noticed that salt level was really high due to evaporating water and he wouldn't eat.  <So are you not topping off with freshwater?>  I did a water change and brought it back to normal. Wednesday he ate a lot, my wife said. Not sure the amount she fed him. He is under 2' from nose to tip of tail. We have been feeing him silver sides. He has been really happy with them.  <Not a real good choice of food for a nurse shark. You could feed a kid a Snickers bars for lunch and dinner (and of course he will love it) but does it mean it is a nutritious food for good health and longevity?...... Try human food grade clam and or abalone chunks. Feed variety maybe some squid, anchovies, and maybe fresh sardines. Careful for feeding too much. They will get fat on anchovies and sardines. You could try prawns as well.> I went to feed him Saturday as I feed him every 3 days and he wanted nothing to do with the food. He has been very lethargic the last few days, not really moving. Just sitting where the blower blows on the ground. That is his favorite spot. I did another small water change to help and tested the salt, ammonia and nitrate levels. Everything was fine.  <Not the only water chemistry test that should be done when one keeps a shark.>  He just wouldn't eat or move much. He did have a white looking color to him.  <This sounds like a monogene (flukes) infection. The white film is defense mechanism (mucous coat) The best thing to do is to get a little scrape of the film and look at it under a microscope (you could take the sample to a vet or a college lab) Without treatment the shark is likely to die. This is my best guess based on you description. There could be other issues here but likely the animal is stressed and the flukes are a result of the stress. To treat this (once it has been positively identified) you will need to treat with Droncit or Praziquantel. You use these by weight. You can buy them as de-wormers (used for dogs) and crush the pills up and use them in food. (which might be a problem for you as your shark is not eating) Which brings me to a point, do realize sharks can go for more than three days without eating. Keep water quality high and wait for a few days.> I tried to feed him again Sunday with no results. Hoping to help jump start his feeding I grabbed some live tetras as they looked small enough to feed him. I tossed in 4 of them and they are still around. I fed the tetra's last night and the shark seemed interested in the food. I bought some scallops and cut it up in to small pieces and tossed it in for him. He would suck it in and then spit out. He acted liked he wanted to eat but couldn't type of thing. I also put in a piece of a silverside as well. No luck. He is now showing a pink color mostly by his dorsal fin.  <Hemorrhaging is not a good sign>  He is making me very nervous as he stopped all his playful behavior... <May not have been playful at all......maybe he was always irritated...maybe something was bothering him from the start> ... and is just laying there most of the time. He did more a bit last night when I feed the tetras. He almost ate on but spit it back out.  Any suggestions? I really want to get him back to his normal self.  <You need to act immediately>  Oh, my tank I know is small for him but this is what I got until I can get a custom one built to keep him for a bit longer width. It is a 180 gallons, 6' long, 2' wide, about 3' deep.  <Wider is more important than depth, but over the long haul this is just too small a tank. You need a great amount of surface space (a very large tank), soft sandy bottom, great filtration, and quality foods. Do read more of our FAQs on sharks. You have to keep you water chemistry to high standards with regular water changes, top off with quality freshwater, and regular testing.>  I know he needs a lot bigger tank but that is what I had. He as in a 30 gallon when I saw him.  <I would like you to recommend to the dealer that he should look at our section on sharks, research his offerings before purchasing and treat to his animals better. Let him know if his practices don't change that you are going to not only stop shopping there but you are going to recommend to others not shop there as well. Don't reward this crap! Regardless of your intention, you are ill prepared for the long term care of your shark. So whether it dies in a dealer tank (where he will learn the lesson that a nurse shark is not a good animal to sell) or you take the shark and it dies in your tank thus frustrating you, and rewarding the dealer with business all cause you feel bad for the shark. Don't get me wrong here Peter, I see where your heart lies, and your intentions were noble (if your true intentions was to save the shark and not because you wanted to try one). Thanks for the question and being part of it all ~Paul> 
Nurse shark in distress follow up - 2/10/05
Thanks for the reply.  <My pleasure.> They white has gone away and the red tinge replaced it.  <Not good, my friend>  I know buying him rewarded the fish store but I felt bad having him stuck in there.  < I understand, but now it has become your issue too>  I am planning on getting a better set up for him I know I won't be able to make one big enough but something he can be in for a while anyways.  <Very noble>  Then I am sure to donate him to a local aquarium.  <Don't be so sure your local aquariums are waiting for the public to drop off animal they can no longer care for. They have space allocation issues too. Not to mention they also have the issue of added bandwidth (food, upkeep, staffing, medical issues...etc.....)>  It has been over a week not a few days since he fed.  <Be forewarned, it is possible this shark is doomed. It seems it was stressed out from the start.>  I will definitely get a better source of food for him.  <Excellent>  Hopefully that will help.  <Well, he has to be willing to eat which is one of the issues we are dealing with here>  With regards to not topping off with fresh water, I had been, I don't know why I didn't, which allow the salt level to increase. Stupid me basically!  <Not something you can afford to do unfortunately> I definitely will try those different foods hoping one will work to get him to eat.  <Good idea>  Thanks again for your help.  <No problem. It is what we do>  I will definitely let that shop know to not offer them again until they are prepared to care for them properly.  <Great. Feel free to offer him this site>  I will work on my system as well. Make sure that it is what it should be.  <Be sure to do your research before picking up any animal stressed or not. ~Paulo>
Update on nurse shark - 2/17/05
Update: The white color is gone and the pink/red color is almost gone as well. <GREAT!!!!!> He has now eating again and doing pretty well. <What changed? What did you differently? Please list for me to put on the site for future shark enthusiasts> He did not like the scallops so I tossed in a few silversides. <Good. What about other foods? Are you using supplements?> He liked that. I am picking up some better food today. <Cool. How is that going?> He also has eaten 3 of the 4 tetras I had in there for him. <I wouldn't feed any more tetras for now> So things are up the up and up by the looks. <So great to hear =) > Plans are in the works for a bigger, better tank for him. <That is what I like to hear. Do realize you will need a very large tank in the range of wide and long as opposed to high. Somewhere in the market of 3000 gallons minimum but ideally around 6000 is better. Again long and very wide is the only way to keep this shark in a stress free environment. It must be able to easily swim and turn in the tank. DO research the adult size and requirements of this shark. I stress researching habitats and natural foods, and filtration. OK? Keep the updates coming! Hope to hear from you soon. ~Paul> Thanks again! Peter
<<? Tetras... in saltwater? Not. B>>

Leopard Shark and Lionfish - No Copper, Please, & No Goldfish Hi, <Hi Tim, MacL here with you today.> I just have a few questions that I have been wondering and you guys seem to be the best fitted to answer the question.  I currently have a leopard shark in a 125 gal tank. I have already read many post from your crew not to keep leopard sharks in captivity, but it's too late I already have one. I would not have purchased the shark if I had done more research on them. The shark is in a 125 and the shark is about 24". I was feeding it Shark Formula put out by Ocean Nutrition until I introduced him to prawn from the local grocery store. It has now been eating the prawn now for about 6 months. Out of no where the shark stopped eating.
<So VERY expected...>
He has not eaten but a few glass shrimp from the local pet shop in the past 2 months. I have tried giving it flounder, scallops, shrimp, and the Shark Formula, but it doesn't seem to want it. It will pick the food up and spit it out. <Sounds to me like your tank conditions might be a bit off, in my experiences with Sharks when they stop eating like that they have high nitrates.>  I had thought that it may have been because I was running CopperSafe with it, but I have not had copper in the tank for some time now and still no progress.  <EEEK, Sharks do have adverse reactions to the copper so that might indeed be the root of the problem. I would do several changes of the water to try to get as much copper out as possible. Also you can run PolyFilters in the tank and see if it turns colors to indicate that copper is still there. Or an accurate test kit as well.>  <Editor's note: Sharks and their kin should be considered as invertebrates, no copper!> So my question is what should I be feeding my leopard shark and why might he be not eating. Could it be some sort of hibernation effect since it is winter months? I am currently in the process of purchasing a 300 gallon tank. to keep him for maybe another year until donating him to an aquarium.  <You should check now with the aquarium you plan on talking to a lot of times they need a lot of advance time before taking the shark and /or they might not want them.>  Another question about the leopard shark, is there anyway to sex them?  <Males have claspers.> I also have a 90 gal tank that I have two lionfish in. I purchased the tank with one lion and it was about 10" at the time and is now about 14", and the other I grew up from a little guy and it is about 10" now. The large lion has always had issues with his side fins growing, they curl as they grow and seem to break easily.  <Tank is too small for him I'm sorry to say. Also he probably has a vitamin deficiency if you are feeding freshwater fish to him.>  I was thinking that it may be from poor nutrition.  <Sounds like you are right on track, they need vitamin supplementation if you use freshwater fish like goldfish to feed them. You should try to get them converted over to things like prawn and smelt etc. Also they need a variety in their diet and not just one type of food. This is much easier to do with the younger fish.>  The smaller lion has beautiful side fins and I feed him all live also, but it is fairly young compared to the larger one. I have read recently that lions should not be fed freshwater fish due to some type of toxic chemical that can harm the fish over time. What should I be feeding my lions. Also, is there any way to sex a lion fish?  <Not that I am aware of, although a male and female tend to stay closer in a tank to each other. Also, there's an amazing article about lionfish in one of last years articles of Coral, great info there. Good luck, MacL> 

Epaulette shark with goiter I purchased a female epaulette shark yesterday that has been captive raised from a pup. It is now about 24 inches. I currently have a 34" male and am hoping to breed them. I have a 1500 gallon shark pond that is 10'x10'x3'. The female I just purchased appears to have goiter. It is eating well, and I feed with Mazuri shark and ray vitamins. Will being fed a proper diet with the vitamins correct the problem or is there something else I can do. Also can sharks absorb Iodine from the water or is it only through food? <Not much from the water (but some), but I would definitely be administering iodide/ate through the animal's foods> I currently dose the tank with Kent's Lugol's solution and am wondering if this will help at all. Thanks <I would look to dosages encapsulated, the capsules placed inside hand-fed food items here... and quickly. Bob Fenner> 
Re: Epaulette shark with goiter
Do you have any idea where I can purchase Iodine supplement capsules? The Mazuri shark and ray tabs don't have iodine listed as an ingredient. <Mmm, yes... at GNC or similar food stores... or you can buy the empty capsules from such places and make your own. Bob Fenner> 
Re: Epaulette shark with goiter
Is there a certain dosage I should give? How many mgs would you recommend?  Is it possible to overdose? Thanks <Is possible... please see WWM re dosages, sharks, iodine/ide. Bob Fenner>
Re: Epaulette shark with goiter
I have searched through your website for hours and can not find anything that relates to the amount of Iodine to supplement. I did see on one post that said not to add iodine directly to the sharks food. Is this only liquid forms? The shark is about 4 pounds. Thanks <Perhaps this search:  <<Previous link not good, removed link for space.  Am adding link using "captive shark goiter iodine dosage".>> or one of your own... Unfortunately am out of State, away from references. Bob Fenner> 
Re: Epaulette shark with goiter
I ordered pills from Mazuri that they say are specifically for sharks with goiter, but they have to make it and won't ship until the 9th. I am getting it overnighted but that is still the 10th. The only supplements I have found in any local stores all kelp. I bought one that says it has 400 mcg of iodine, but also has 300 mcg of iron.  Will the iron cause a problem? Is this enough Iodine to get me through till the Mazuri arrives? The capsules are also pretty large and I don't know if she will swallow them or just spit them out while trying to swallow the food. If you know of anywhere I can buy better human Iodine supplements please let me know. She also refused food yesterday for the first time. How long can I let this go before force feeding? Thanks for the help <Am still away... am cc'ing Paul Mansur re your questions. Do you have Scott Michael's shark and ray book? Access to a large library to do a computer search bibliography? BobF>
Re: epaulette shark, force feeding, health
I talked to you about a month ago about an epaulette shark that I purchased form someone that raised it from a pup to ~ 24". When I received it I noticed it had a pretty large goiter and would not eat. I have been tube feeding about 20ccs every 4-5 days since then. I grind 2 Mazuri tabs that were made for me that are supposed to have extra Iodine in them for sharks with goiter. I don't know how much Iodine is in them because Mazuri does not put an ingredient label on them apparently. <Strange... I would write them directly re... and if interested, either test or have their product tested for iodine. I think others have told me Mazuri did not have iodine content> I also for the past 2 weeks have been adding a drop of Lugol's soln to the food. I don't know if this is good or not but I am starting to think the shark is going to die no matter what I do. The question I have now is feeding every 4-5 days about right or should I wait longer to see if she will eat on her own? <Is about right> Is 20 ccs right? <Does the fish seem thin?> When I feed she seems to regurgitate some of the food. It seems like she keeps down about half. Is that normal? <No> I try feeding normal food every day, but she seems to almost be afraid of it and moves away almost immediately. How long should I continue to tube feed before giving up? Thanks for any help. <As long as you have patience, interest. Please read here: Particularly at the bottom. Bob Fenner> Erica Vandegrift

Epaulet shark tumor? Hello: I have a question about an epaulet shark "tumor". I have had my shark for almost 6 years and he has always been in good health. However, over the last 6 months or so he seems to have a large "tumor" under his head, just behind his mouth. He still gets around and eats fine. He has eaten frozen cube food and nothing live. This condition looks red and painful to me. I have asked a local shark expert and he said it was normal for a male epaulet shark to develop this. But it looks like he swallowed an air hose. I wonder if there is any treatment for this condition. Please help Thanks Joe <Please help yourself. Such goiters in sharks are mentioned, and their simple cure... on WWM... go there, use the search tool, indices... read. Bob Fenner> 
Re: epaulet shark tumor
Thanks for the info, I will give it a try, and send you before and after pictures. Only one question remains - what is the dosage, I ordered the SeaChem product mentioned on your site. The shark is aprox 29 inches long. <Please see here: at the bottom... "Heavy supplementation of susceptible sharks with massive dietary iodine levels (10 mg/kg body weight supplementation of potassium iodide (Sea World, 1985) in the feed once a week) is effective in avoiding the appearance of goiter in brown sharks. However, this level of iodine is not a simple supplementation to balance an iodine deficient diet. In closed systems, the iodine content of the seawater will rise dramatically from the iodine excreted from sharks on this supplementation plan." <Bob Fenner> 
Re: epaulette shark
The goiter seems to be getting smaller but the shark still will not eat. I read on WWM that vitamin B12 can stimulate their appetite. Do you know what dose should be given? The shark is about 2.5 pounds. Also where can I buy vit B12? Thanks for help. <Mmm, the concentration and other useful information re this vitamin is mentioned where you were referred to previously... Such adjuncts can be purchased from companies like Mazuri, or from any source (the compounds are identical for humans) and added, encapsulated and placed in foods. Bob Fenner>

Shark with possible goiter or isopod - 6/7/05 I'm dealing with second hand information. <Uh oh>  So my description may not be as specific as needed, but here's the problem: 22 inch Marble shark, in tank for at least 2 yrs, has developed this lump that is visible below mouth. <Hmmmm...sounds like it could be goiter but just a preliminary guess at best>  And maybe poking up in the mouth. <Sounding more like goiter> Sharks feeding is still consistent, and doesn't appear to be in discomfort. My take without viewing it personally is either it's a parasitic isopod attached on the inside of the mouth.  Or a goiter. <I would likely treat for goiter. Try www.mazuri.com and select their Vita Zu - shark and ray tabs either the 5MD8 or 5M24. Whatever works best for the owner. Follow instructions for application from label or from their site> If when viewing one of these guess is right, what is standard treatment for each? <Mazuri tabs are best and for isopods it might need to be treated with Praziquantel. Please see here: http://www.wetwebmedia.com/shkdisfaq2.htm Thanks so much.  Btw,  I was told that a friends shark has a similar lump, that has gotten larger or decreased in size from time to time. <Sounds like goiter. Thanks for being part of it all. ~Paul>

Sting ray goiter picture WWM crew, A while back I wrote to you about our California Ray's goiter problem.  It's getting a lot better with the addition of Seachem's Iodide treatment just over the last few weeks.  Anyway, I thought your readers might be interested in seeing what goiter looks like, since it seems to be such a common problem with elasmobranches.  This picture is of Norma the Ray at the height of her goiter problem. <Thank you for this pic and progress report Sherry. Good to hear of the improvement. Bob Fenner>

Does my Smoothhound Shark have back and stomach problems? Hi, I just bought a gray Smoothhound a few days ago. I then bought a copy of the Shark & Rays book that you are always recommending. <A bit out of order> I read in the book that I shouldn't pick a shark with parasites or a curved back. I now have noticed that my shark's back seems curved and not straight as I have seen in pictures. <It does appeared to be significantly curved> Also on one side, it seems like he gets these ripples on his stomach that show up occasionally when he is swimming. What are these symptoms indicating and is he able to recover? <Am not so concerned re the stomach markings, but the back may be indicative of developmental disorder... perhaps due to lack of nutrition> And would he have been able to develop this kind of problem in just a couple of days? <Not likely> I suspect that he was like this when I got him but I am not 100% sure. I also noticed that the shark seemed to have a parasite that was attached near his rear fin when I saw him at the store (the parasite looked like lint and was small and somewhat white and clear). The owner took it off of the shark and told me that it would not affect the shark's health. Could this be the cause of his abnormalities? <Highly unlikely> I have included pictures to show you what I mean. Thanks for any help you can provide. Sincerely, Steve <At this point I would try augmenting this fish's diet (with iodine, HUFA's and a general vitamin mix added to its foods). Bob Fenner>

Bamboo Sharks Thank you so much for the great help. I guess I am kind of wondering what  are some signs of a healthy bamboo shark?< The single most important is probably the presence of a healthy appetite, for, like most of the moray eels, they have an extremely acute sense of smell.  Physically, you should probably look for a lack of red areas on the abdomen or other signs of inflammation.>   I know they are pretty mellow  sharks, so I was just wondering if there is any way to tell that they are happy  and doing ok? <Again, as with many other marine animals, a healthy appetite is always one of the best indicators.  Even though they are primarily nocturnal by nature, the scent of food in the water should at least bring their nose out of the LR in a fairly short time, and the longer the shark is with you, the more this becomes evident.....after a year, mine has no hesitation about feeding from my fingers at the surface of the water, even in broad daylight and has moved well into the "bottomless pit" category. The best of luck with your new baby and don't hesitate to spoil it at every opportunity.>     Thanks a lot John & Tiff  Proud parents of  a new bamboo shark  

Sharks and Rays in Aquariums
Gaining an understanding of how to keep these fishes in captive saltwater systems   

New Print and eBook on Amazon

by Robert (Bob) Fenner
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