shrinking fish

Question
Hi Karen,
I have a 55 gallon freshwater tank and I think some of my fish are shrinking. I think they are shrinking and larger fish are eating them...although I have yet to witness the latter. I first had to pink kissing gourmis (sp? that shrank and now are gone. One shrank in size SIGNIFICANTLY...I mean got very small and then disappeared. Before I knew it the other one was gone as well. Now I have a Tiger Barb (I actually have four of them) that is literally shrinking before my eyes. Yes they were all the same size and now this one is beginning to look like a baby. I watch her eat every time and she IS eating. I just know that she is next! Have you heard of anything like this before? Is there anything I can do to save her? (I do have to rather large Silver Barb who I think are the bullies in the tank......not sure if they are the culprits now though)

Answer
Hi Katie,
Wow! That's something I've never heard of before. What you mean is the fish's size itself is getting smaller or the fish is losing a lot of weight and looking emaciated?

I honestly not sure on what to tell you.. If you have any pictures of the fish that would be great so I could get a better idea of everything. If you like, you can send me pictures. Just request my email address in your next letter and be sure to set the letter to "PRIVATE".

I'd imagine the only way a fish might shrink is if they were losing considerable weight. Some of the causes to this would be poor nutrition or internal parasites. That's probably the first thing I'd suspect is some sort of disease or parasites. Can you test your water for ammonia, nitrites, and nitrates? Knowing these levels is very important whenever you have fish problems like these. It helps determine if poor water quality is the cause or contributer. Poor water conditions are the number 1# cause to fish illness.

I'm wondering too if the Silver Barb (tinfoil barb?) is hogging all the food from the other little fish? If the silver barb is in fact a Tinfoil barb, I know for a fact that he is likely taking all the food--tinfoil barbs are very bold and eager eaters.

But if all your fish are getting their fair share then I may suspect internal parasites. How is the fishes poo? Is it white and long and stringy? (Sorry for being so graphic) If so, then this would most certainly indicate internal parasites. Sometimes they can be sucessfully treated but its not always guaranteed. You'll need to try to get your fish to eat a medicated anti-parasite food. I've used the ones called "GEL-TEK" for internal parasites before on a miserably little Dwarf Gourami and he recovered well from his bout of internal parasites. It takes lots of patience to try to get your fish to eat the medicated food, the first time they will most certainly refuse to eat it at all but you have to keep trying. Try different methods to find one that works for you. I usually soaked the GEL-TEK in a fish-safe (no chemical or soap residue) cup with some frozen worms or brine shrimp that had been thawed, and using an eye-dropper directly feeding it to the fish. They may or may not gobble it up but you have to just keep trying different foods like pellets or flakes. Eventually I got my little gourami to actually swallow a drop of the GEL-TEK medication. Sometimes you can trick them.

One thing that's probably going to be a potential problem is your Silver barb. I bet he will gobble up every last little bit of any medicated food or food soaked with medication and the little barbs or other fish that need it wont get a chance. In this case it would probably be best to move the infected fish to their own treatment tank if possible.

Keep the water quality at its highest through large daily water changes and work with them to get them to accept the anti-parasite food. Another medicated food many sources recommend is "Pepso food" if you can find that you should try it also. I've also heard that garlic extract can discourage internal parasites also. You can find garlic extract at petsmart, I believe I've seen it numerous times there in the fish food/water conditioner section. Garlic often encourages difficult fish to eat and has been used on discus countless times. Definitely something you might want to consider.

I really hope this helps!
Best of luck with your poor fish!
Karen~