sick freshwater shark

Question
Our shark has been acting ill for about a week. At first he was laying on the bottom of our tank, but if you touched him with the net he would swim around for a little while, then go back to the bottom. We thought the tank was to cold, it was very cold outside -20. Then he started acting normal. Then a couple days later he start swimming to the top of the tank jumping out of the water like he is trying to get more air,but hits his nose on the top of the tank. Now he is on his back but still will swim around when prompted. We just don't know what to do. Out tank is a 55 gallon tank. The filter system hangs in the back of the tank.We have had this tank of about 9 months. We have had the shark for 1 1/2 years, we also have 5 large goldfish and a bata in the tank, all the same amount of time.

Answer
Hi Pam,

You should never ever keep coldwater fish, such as goldfish, with tropical fish like sharks and bettas.  Goldfish are coldwater fish, only compatible with other goldfish, require temps of 64-70 F and a much larger tank and filtration unit, not to mention a very different diet.

Goldfish require 20 gallons for one and 10 gallons for each additional with double capacity filtration.  You need a 60 gallon tank with 120 gallon filtration for 5 goldfish.  I would keep them alone in the 55 gallon and move the shark and betta asap.

The shark and betta really do need their own tropical tank with at least a temp of 78-80 stable as soon as possible.  I am not sure what kind of shark that you have but most require at least a 50+ gallon tank for just one.  Even a clear plastic 50 gallon rubbermaid with a hang on filter and heater would be better at this point.

I would definitely test your water asap for ammonia and nitrites.  All fishkeepers should have a liquid drop test kit and monitor the levels in an established tank monthly.  Any switch in these and immediate action should be taken so that your fish don't get sick and stressed and die.  99% of fish illness and issues is directly related to the water quality so keeping an eye on these is extremely important.  Your ammonia and nitrites should always be 0, nitrates always 5-20 ppm.  It's quite possible that even if these were in line the stress of being in a coldwater tank finally took it's toll on him.

From laying on the bottom of the tank to thrashing around it sounds like a parasite infestation, look for red gills, off color, distressed breathing, a 'salt sprinkled' look or a 'baby powder coated' look.  Any lumps or bumps or slimy white patches.  It really depends on his symptoms to accurately diagnose and just laying on the bottom and thrashing isn't enough information to say specifically what it is without any other outward signs.  I think simply separating him into his own warmer tank with some Melafix and aquarium salt will help for now.  Melafix is for bacterial infections but you don't want to treat him for parasites until you know what exactly it is.

Good luck : ) April M.