What to Look for in a Healthy Fish

One of the first steps to preventing fish problems in your aquarium is to purchase healthy stock. However, that can be a difficult task in itself if you haven’t been keeping fish for very long – especially if you’re trying to sort through a tank that has a couple dozen fish in it. There’s a lot more to check than simply making sure it’s swimming! Here’s a quick breakdown of what I look for before I commit to buying a fish.

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1. Examine the overall appearance of the fish. When I do this I’m looking primarily at the color – is it dull? Does it appear sickly or malnourished? If the color is very pale compared to the rest of the fish the one in question is probably suffering from some kind of stress or illness. You also want to pay very close attention to the belly – a fish with a very sunken appearance to its stomach is likely carrying internal parasites.

2. Observe the way the fish is swimming. This should only take you a couple of minutes – all you are doing is watching the way the fish swims in comparison to the rest of the fish in the tank. You should avoid purchasing a fish that is bottom sitting or scratching against objects.

3. Examine the fins. This is a very easy step because there really isn’t a lot that you need to look for. However, the condition of the fins can tell you a lot about the health of a fish. For instance, you do not want to purchase a fish that has red streaks or white cottony growths along the edges of the fin. If the fins have a very shredded appearance or look like they are being eaten away by something do not purchase anything from that tank!

4. Examine the feces if possible. You are ideally looking for a fish that has solid strands of poop, not one that has clear or very stringy poop. While you are observing the feces, make sure you also take a quick look at the vent (where the poo is coming from). You do not want to purchase a fish that has a bloody or very swollen, irritated vent.

5. Look the fish over to see if it is missing any scales. The scales on a fish act like a layer of armor in respect to its immune system – these are the first things that any bacteria or parasite come in contact with. If the barrier is compromised in any way, like a patch of missing scales, the fish is left very vulnerable to infection and disease.

6. Look for any growths, lesions or fuzzy patches. This one is pretty self-explanatory – you do not want to purchase a fish that has any open wounds, ulcer-like markings, or fuzzy patches on its body/fins. You should also be on the lookout for fish that look like they have been sprinkled with salt – if any fish have this appearance do not buy anything from the tank.

7. Observe the other fish in the tank. After you have taken the time to examine the fish you want to buy, take a couple minutes to look at all of the other fish in the tank. You ideally want to find a tank that doesn’t have any dead fish floating around. However, please keep in mind that it will be almost impossible to find a tank that meets that criterion if you are shopping in a large chain pet store. The tanks at these stores are grossly overstocked which makes dead fish an inevitable reality. Instead, make sure that the fish do not have any visible external parasites, growths or signs of fish ick.

The goal of the above check list is to help you pick out a healthy fish; however it is not implying that you should be rigorously examining the fish to make sure it fits show quality standards.  For instance, if the fish you like has a minor flaw, like a bent fin, but otherwise appears healthy then go for it! There is a lot to learn about proper fin and body conformation, and the chances are very low that you will find a perfect specimen shopping at one of the large chain pet stores.

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