Dumb Fish Stories

Everybody's talking about this crazy PETA comic that claims that fish are smart enough to use tools, so I thought I'd take the opportunity to tell some Dumb Fish Stories.

FH and I have been keeping fish for most of our 12-year married life. My very first fish was a betta that I bought to keep me company while FH was in Korea. This fish spent his entire day swimming around and around in a more or less spherical bowl. We put a mirror along the side of the bowl, and every time he'd pass the mirror he'd flare up and give nasty, aggressive looks to the "other fish". He spent every waking hour doing this, until the day he contracted fin rot and died.

When FH got back from Korea, we got a larger tank with some more interesting fish. We got two convict cichlids and two jewel cichlids-- the guy at the pet store assured us they'd all get along. Several dead fish later, we discovered that the problem was one of the jewel cichlids. He was biting the tails off the other fish one bite at a time, then coming in for the kill when they didn't have enough tail to swim away any more. By the time we discovered this we were down to Spot (the over-aggressive jewel) and one half-tailed convict we'd named Sergeant, so we put in a tank divider. At first we noticed that Spot was moving the gravel, one rock at a time in his mouth, trying to dig under the divider. Then we heard this "Thunk!" sound from the tank. Spot had jumped through the air, over the divider, ricocheted off the hood, and was going after Sergeant with a vengeance. After that, we got Spot his own tank, where he spent his time threatening the fake plants. We put a mirror in his tank to keep him company, but he kept on bashing his head against it trying to attack the other fish. When the mirror fell over and lay on the bottom of the tank, he hovered head down over it. When we'd reach in to adjust something in the tank, he'd bite our fingers (it didn't hurt; his teeth weren't big enough to penetrate the skin). My brother took advantage of this to torment the poor fish-- he'd just put his finger on the glass and laugh his butt off while Spot repeatedly ran himself headfirst into the side of the tank. Meanwhile, Sergeant got a larger tank, which he shared with his three new bunkmates, all female.

People, fish are dumb. The only "tool" I've ever seen them use is their own mouth. They will take advantage of things in their environment, like hiding in plants or making their own hidey-hole in the gravel, but that's about what you'd expect from any dumb organism capable of movement. You can catch the same fish over and over again in a lake. They've got the brains of... well, a fish.