Blue is a rare color in nature, especially in freshwater fish. It is really hard to find. My best theory says the reason for that is because blue things stand out in nature and are more likely to be eaten—but that’s just a theory.

So, anyway, if you’re tired of red and yellow, or black and silver, here is my list of blue fish you can put in a community tank (note, this list excludes varieties that are difficult to keep, like African Ciclids or Discus).

SEVEN: Zebra Danios have blue and yellow stripes. They’re pretty cool, but the blue only shows up in direct sunlight. I like Zebra Danios. I bought a whole bunch and put them in my 20 gallon tank, but they have been disappearing. I think my Red-Claw Crab has been having a little midnight snack. I digress.

SIX: Also on my list are the Powder-Blue Gouramis. These are really kind of washed out, and not really a vivid blue, but they are blue nonetheless.

FIVE: For a less washed-out shade of blue you can try some three-spot gouramis. They have one spot on their tail, one spot in their middle, and their eye makes a third spot. Here’s a pic of one I got from About.com

FOUR: Did you know you could get blue Mickey Mouse Platties? I was very impressed, so I bought a whole bunch. I have six of them. In the right light they really show their color. In normal light they look powder blue. Here’s a pic:

THREE: Next on my list are Opaline Gouramis. I read in my fish book that these guys can be fairly aggressive. They grow to six inches. I bought one, thinking they were pretty cool. I got the bluest one I could find. He was only half the size of the yellow gourami in my tank, but he soon asserted himself at the top of the pecking order. Man, feisty! He is now the same size as the yellow gourami.

TWO: Neon Tetra. I hadn’t realized how brilliant blue these guys can be until I passed a tank full of them in a pet store. They’re not pure blue, but they have a brilliant, iridescent blue stripe. Very attractive. I wish they got bigger. I won’t buy them. Here’s a nice pic from aquariumfish.net (one of my favorite sites)

ONE: Betas are next on my list. If you want pure blue in a freshwater fish, this one is hard to beat. Unfortunately, they are not compatible with everything. It will attack anything that has looks remotely like another beta. This includes anything with long fins, or fins that stick up (like angel-fish). These fish can be super aggressive. They flare out their gills and spread out their fins. It is very dramatic to watch. To their detriment, they are really tiny, and their long fins make them fairly slow swimmers, so they are easily bullied by other aggressive species (especially tiger barbs). They mix well in a small community tank with peaceful fish that DON’T look like betas, like white clouds and neons. Gouramis and bala sharks also do all right. It’s too bad they aren’t more peaceful. Their vivid colors would make them super popular.

I had a beta once. He attacked my angel-fish. Apparently angel-fish look very aggressive the way their fins splay out, so the beta thought they were challenging him to a fight. I had to move the beta to the 20 gallon tank, but that tank has a mirror in the back and he kept attacking his own reflection and wouldn’t eat. Finally I took him to a pet store and unloaded him. That’s when I got the blue platties. The pet store owner told me that customers commonly complain about betas attacking angel-fish. Go figure. Here is a pic from somewhere on the web.

If you are a little more advanced, you can definitely do better than this list. African Cichlids sport some pretty amazing colors, and are definitely king of the freshwater blues, IMO. Also, breeders have managed to create some very striking breeds of blue discus (you have to order them over the web). Discus can be a PITA if you aren’t that serious about keeping fish. They are expensive and disease prone—definitely not worth it if you are only half-way committed. Someday I’ll give them a try, if I ever live somewhere that the tap water isn’t super, super hard.