Dear Neely,

As a science cat, I handle going to the veterinarian better than most. I see it as a meeting of scientific minds. But I had no idea some veterinarians specialize in fish.

I learned all about fish medicine from my friend Nora Hickey. She’s a fish veterinarian at Washington State University. She works in the Washington Animal Disease Diagnostic Laboratory. She helps fish at zoos and hatcheries stay healthy.

Hickey told me you can watch a betta’s behavior to see if it’s happy. Happy bettas swim around. They interact with things in their tanks and act interested when you come close.

Dr. Hickey’s happy betta Seabiscuit acts interested when she approaches his tank.

 

Unhappy bettas are lethargic. They lay around and seem uninterested. All bettas rest sometimes, but a betta that’s always inactive may need help.

“The biggest reason for betta fish to be unhappy is that they’re not properly kept,” Hickey said.

She told me bettas are tropical fish and need heaters. Their ideal water temperature is 78 F. A lethargic betta without a heater may be cold.

You might be surprised to hear that bettas don’t always need filters or bubblers. Hickey says filtration systems that churn the water may annoy bettas. Their native waters are still, and they aren’t strong swimmers.

Most fish use gills to get oxygen from the water. But bettas belong to a fish family called labyrinth fish or anabantoids. In addition to gills, these fish have a breathing organ inside their heads—called a labyrinth organ. They can breathe air by poking their mouths above the surface of the water.

It’s an adaptation that helps wild bettas survive. Wild bettas live in warm, shallow waters with lots of plants. Sometimes their homes dry up a bit. That would be bad news for most fish. But labyrinth fish can breathe air. As long as they stay wet, they can wait until their homes fill back up with water.

That’s why the shape of a betta’s tank is more important than its size. Bettas need lots of surface area—space where the air touches the top of the water—so they can gulp air. A betta in a wide tank can breathe better than a betta in a vase or a bowl with a small opening.

Food is another way to make your betta happy. Hickey told me wild bettas eat insects. Betta food made from insect protein is a diet closer to their normal one. As a treat, offer bettas frozen foods—like blood worms or water fleas.

Bettas are solitary animals, but they do like to have one friend—you.

“I think they’re one of the most interactive fish,” Hickey said. “Bettas like to interact with or respond to people.”

She told me some people train bettas to do tricks like jump through hoops. You can enrich your betta’s life by talking to it and offering it tasty nibbles. You can give it new things to explore in its tank.

If your betta still seems lethargic, it may need a fish veterinarian. They can help you and your betta get on swimmingly.

Sincerely,

Dr. Universe