I have a yellow tang that is very skinny. I feed everyday sometimes twice a day. Everyday I do a big pinch of flake and about a 3in x 3in sheet of nori. Also, about every other day I do a frozen cube of either mysis, brine, or a mix. I think it is enough to keep a fish fat and healthy. My tang eats and swims as if it is healthy but he just doessn't gain any weight. The only thing I can think of is possibly an inernal thing. I have heard of dideases where a parasite or something takes all of the fish's nutrition. Could that be what is causing him not to gain weight? Is there any cure if that is what it is? I have had the fish for about 6 months and he was fat and healthy when I got him. I noticed this about 2-3 months ago. Any help would be greatly apprciated.
Skinny Fish
- Thread starter Dan9
- Start date
Puffer Queen
New member
Definitely could be internal protozoans or worms. I would recommend deworming this fish immediately.
There are many threads on deworming fish - I know I have contributed to so perhaps doing a search of these threads.
Best of luck.
There are many threads on deworming fish - I know I have contributed to so perhaps doing a search of these threads.
Best of luck.
My 02
Tangs are one of those fish that need large mature tanks because they tend to need more "swimming room" than most fish and tend to graze constantly (hence the need for mature algae filled tanks).
If your fish doesn't have sufficient ongoing food source in the tank you might consider more frequent feeding ... kinda of a double edge sword since that can create water quality issues. Frequent feeding with healthy food should help the fish .. but be cautious/selective on what you feed because the more food you put into the tank the greater the likelihood you will have water quality/algae issues and some food like "flake" is loaded with phosphates which is basically a plant fertilizer.
You might consider frequent small portions of food that has been enriched by soaking in Selcon or other supplement .. just a thought.
Tangs are one of those fish that need large mature tanks because they tend to need more "swimming room" than most fish and tend to graze constantly (hence the need for mature algae filled tanks).
If your fish doesn't have sufficient ongoing food source in the tank you might consider more frequent feeding ... kinda of a double edge sword since that can create water quality issues. Frequent feeding with healthy food should help the fish .. but be cautious/selective on what you feed because the more food you put into the tank the greater the likelihood you will have water quality/algae issues and some food like "flake" is loaded with phosphates which is basically a plant fertilizer.
You might consider frequent small portions of food that has been enriched by soaking in Selcon or other supplement .. just a thought.
Thanks guys. I really don't think it is an issue of not enough food. I have been really trying to feed a lot and have been adding a food booster as well. Does anyone have any links to the internal disease. My search doesn't work. Again, thank you and any more input is appreciated as well.
Spracklcat
Disaster Expert
Praziquantel (Prazi Pro brand name) is a good dewormer, as is Panacur (fenbendazole). Panacur is used in cats and dogs so you may be able to get it from a friendly vet if you can't find PraziPro for some reason.
Here is an old thread :
http://reefcentral.com/forums/showthread.php?s=&threadid=11744
Here is an old thread :
http://reefcentral.com/forums/showthread.php?s=&threadid=11744
Spracklcat
Disaster Expert
My instinct is to say not to give any medication unless you know you need it. That said, veterinarians routinely deworm puppies and kittens without a diagnosis of parasites just on the presumption that most puppies and kittens have worms. At this point, weigh your options--do you have anything to lose by treating? Probably not. Is the fish getting better without treatment? No. So--go ahead and try it. 
Puffer Queen
New member
According to most fish vets, at least 70% of all fish brought into the hobby have some form of intestinal worms/parasites.
I deworm everything - fish, seahorse, sharks.
Worms can co-exist within a fish for weeks to months. I have a puffer not exihibit any symptoms for over 18 months. As long as the fish can consume enough food for both its own needs as well as the worms, there will not be symptoms. If the fish can't or the worm population increases, then one will begin to see symptoms.
If the worms are not treated, they can migrate out of the stomach/intestines to other organs - spleen, liver, kidneys, spinal column. I have many pictures of worms in these areas. Once they have migrated out, deworming is not an option.
I deworm everything - fish, seahorse, sharks.
Worms can co-exist within a fish for weeks to months. I have a puffer not exihibit any symptoms for over 18 months. As long as the fish can consume enough food for both its own needs as well as the worms, there will not be symptoms. If the fish can't or the worm population increases, then one will begin to see symptoms.
If the worms are not treated, they can migrate out of the stomach/intestines to other organs - spleen, liver, kidneys, spinal column. I have many pictures of worms in these areas. Once they have migrated out, deworming is not an option.
Anthony Calfo
New member
I disagree... most fish do not have internal parasites that are expressed in any deleterious sign (not "symptom"... humans have symptoms... animals have "signs").
Do consider that of the literally tens of thousands of fishes that are imported each year for the hobby... almost none are medicated for internal parasites. And of the majority of folks that successfully keep marine fishes (not dewormed if medicated for any reason whatsoever)... where are these "70%" infected fishes going?
And even if a majority are infected (I've never seen a single study to remotely back up that claim)... is it of any consequence if the majority of them (the legions of thriving, living fishes in our aquariums) NEVER express signs of internal parasites?
My point is... lets not lose focus here. Skinny fishes are not often or at least always suffering from internal parasites. There are a range of other possible reasons.
For starters... no one has asked this poor fellow yet if the fish in question as exhibited the CLASSIC sign of stringy white feces?
Do consider that of the literally tens of thousands of fishes that are imported each year for the hobby... almost none are medicated for internal parasites. And of the majority of folks that successfully keep marine fishes (not dewormed if medicated for any reason whatsoever)... where are these "70%" infected fishes going?
And even if a majority are infected (I've never seen a single study to remotely back up that claim)... is it of any consequence if the majority of them (the legions of thriving, living fishes in our aquariums) NEVER express signs of internal parasites?
My point is... lets not lose focus here. Skinny fishes are not often or at least always suffering from internal parasites. There are a range of other possible reasons.
For starters... no one has asked this poor fellow yet if the fish in question as exhibited the CLASSIC sign of stringy white feces?
Puffer Queen
New member
According to Dr Lewbart (NCSU - Fish Health Conference 2006 & 2007), "nematodes are common parasites of fish and can be abundant in wild species.......While the presence of these parasites may not cause a problem in nature, these stresses of captivity and shipping may exacerbate any parasitic problem."
Worms can be a chronic stressors which can weaken the overall health of the fish/weaken the immune system and contribute/lead to other disease processes that could kill the fish. A fish that is under chronic stress may not be able to handle other stressors - ie power outages, missed water changes, etc.
Unfortunately only a few hobbyists will perform necropsies so the cause of deaths (and incidental findings) that occur in home aquariums go undiagnosed/undocumented.
Worms can be a chronic stressors which can weaken the overall health of the fish/weaken the immune system and contribute/lead to other disease processes that could kill the fish. A fish that is under chronic stress may not be able to handle other stressors - ie power outages, missed water changes, etc.
Unfortunately only a few hobbyists will perform necropsies so the cause of deaths (and incidental findings) that occur in home aquariums go undiagnosed/undocumented.
Spracklcat
Disaster Expert
Wow, big difference between "most fish vets say 70% in captivity" and one fish vet saying nematodes are common in the wild. Using real numbers like that without studies to back them up is misleading at best.
But let's not derail this: as Anthony said, Dan, is there any stringy poop? You said above that you were feeding a "food booster". What is it? And if you feed more does the skinniness abate?
But let's not derail this: as Anthony said, Dan, is there any stringy poop? You said above that you were feeding a "food booster". What is it? And if you feed more does the skinniness abate?
One of the Grad (doctoral candidate) students that I work with did some research into nemetode parasites in Bluefish. She was rather surprised that it was the rare bluefish that did not have a significant parasite load. While this is a species that migrates between temperate and subtropical waters, it does show that nemetode parasites are indeed common in wild fish stocks.
In the case of an aquarium fish being fed plenty and eating well, but being very skinny, odds are high for some kind of internal parasite. While stringy white feces can be a sign of internal parasites, not all internal parasites will give that sign. So lack of that particular sign is rather meanlingless, while at the same time presence of such would be positive indicator. In this particular case, I would go ahead with prazi or panacur.
Spracklcat
Disaster Expert
Dan--how's your tang? Did you end up treating it with a dewormer? How's his appetite?
With regard to wild fish having parasites versus captive fish having parasites: we have to be careful about using data from one thing to prove the point of another. If wild, temperate species have worms, does that mean that captive fish in aquaria 6 months (as Dan's fish has been) has worms? No. Does it mean it doesn't have worms? No. It doesn't mean anything other than exactly what it says: wild bluefish often have nematodes in the waters off LI. More importantly, if a fish veterinarian says "most fish I've seen have parasites" does that mean that most aquarium fish have parasites? No again, and why? because most fish seen by vets are sick . That's like working in an obstetrician's office and saying "most women in the world are pregnant". You can't use a specialized subset of a population to infer things about the whole population
In order to be able to quote a percentage of captive fish infected with parasites, one would have to go out and survey lots of aquarium fishes (sick and healthy) and test them for parasites. Then you could say "70% of captive aquarium fish have parasites". Maybe someone has done this already; if so, then that would be a good backup for the claim. Otherwise, saying that wild fish have parasites is irelevant.
I'm not trying to say here that aquarium fishes have parasites or not--part of the reason I am pushing this point is that I would love to know the actual facts, and I don't. Instead I am saying that no one has provided data in this thread that they do or they don't. We need to be careful to interpret scientific studies narrowly, and not extrapolate data from one thing to an unrelated thing. Studies of wild fishes are a great guide for what to look for in captive fishes, but we can't quote wild fish data to speak about captive fish.
So who wants to do fecal samples on hundreds of fish to determine captive fish parasite loads?
With regard to wild fish having parasites versus captive fish having parasites: we have to be careful about using data from one thing to prove the point of another. If wild, temperate species have worms, does that mean that captive fish in aquaria 6 months (as Dan's fish has been) has worms? No. Does it mean it doesn't have worms? No. It doesn't mean anything other than exactly what it says: wild bluefish often have nematodes in the waters off LI. More importantly, if a fish veterinarian says "most fish I've seen have parasites" does that mean that most aquarium fish have parasites? No again, and why? because most fish seen by vets are sick . That's like working in an obstetrician's office and saying "most women in the world are pregnant". You can't use a specialized subset of a population to infer things about the whole population
In order to be able to quote a percentage of captive fish infected with parasites, one would have to go out and survey lots of aquarium fishes (sick and healthy) and test them for parasites. Then you could say "70% of captive aquarium fish have parasites". Maybe someone has done this already; if so, then that would be a good backup for the claim. Otherwise, saying that wild fish have parasites is irelevant.
I'm not trying to say here that aquarium fishes have parasites or not--part of the reason I am pushing this point is that I would love to know the actual facts, and I don't. Instead I am saying that no one has provided data in this thread that they do or they don't. We need to be careful to interpret scientific studies narrowly, and not extrapolate data from one thing to an unrelated thing. Studies of wild fishes are a great guide for what to look for in captive fishes, but we can't quote wild fish data to speak about captive fish.
So who wants to do fecal samples on hundreds of fish to determine captive fish parasite loads?
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