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Air-Breathing Fish?

“There’s a lot of fish that breathe air,” says Bill Cline. “They come from water that’s low in oxygen, so they’ve developed the ability to go up and breathe atmospheric air to fill in the air that they don’t get from the water. And bubble nests are a way of providing the environment for the babies and the eggs. If the fish can’t live without breathing atmospheric air, then if they laid their eggs in the water, then the eggs probably couldn’t survive. And there’s a lot of ways that fish can get around that. So there’s a family of fish — the anabantids — and others, too, that spit their eggs into a nest of bubbles at the surface, so they stay wet, but they also have the oxygen in the bubble that they can breathe. And atmospheric air has a whole lot more oxygen in it than water does.”

These fish are clearly a kind of modern version of the ancient evolutionary link between the ocean and land. And you can keep them in your living room.

“The lungfish requires a whole lot of air,” continues Cline, “and they wouldn’t live very long if they were underwater. When they lay their eggs, it’s in a mud hole. And they lay their eggs down there, and the parent will go up and breathe atmospheric air, and they have pectoral fins that have a webbing on them. And as they’re breathing the oxygen in at the surface, the oxygen is leaving their body through the fins, into the water around their eggs.”

Electric Fish?

“There’s an electric eel, an electric ray, and an electric catfish,” Bill Cline says. “Any one of those, if they get big enough, could knock you off your feet. They contract their muscles. It’s like isometrics. And when they do that, all of their energy goes into production of electricity. You wouldn’t want to keep any one of those with other fish.”

You’ve Got Ears Like a…Fish?

“The truth is, fish aren’t all that visually oriented,” Bill Cline says. “They do see in color, which dogs and cats can’t do. But they’re very hearing oriented. For instance, you may have seen films of schooling fish in the ocean that move as one. When one moves, the others move instantaneously. That isn’t because they’re watching the other fish. It’s because they’re hearing the other fish. They have a lateral line down their sides which they use for hearing low-frequency vibrations. And sound travels so well in water, it’s almost like the fish are blending feeling and hearing at the same level.”

Upside-Down Fish?

“There are some fish that have no sense of up or down,” Bill Cline says. “The upside-down catfish spends more time upside-down than it does right side up. Most fish have a color that’s dark on the top and light on the belly. That’s so something that’s looking down on them will be looking against a dark background and they’ll see the dark color on top and they’ll miss it. And something looking up from below will see the white belly against the white background, and they’ll miss it. But the upside-down catfish is darker on his belly than he is on his back, so when he swims upside-down, he has the same advantage.”

Charismatic Fish?

“I’ve had lionfish and groupers, big saltwater fish, that have definitely had personalities and likes and dislikes,” asserts Debbie Lara from behind her small round glasses. “You know, you have the little laser pen that you shine on the floor for the cats? Well, my grouper would be chasing it right along with them. Or the light from your watch would shine on the ceiling, and he would try to get at it. He also got so he recognized me. You know, my husband would walk by the tank, and he could care less. I’d walk by the tank, and he’d be up at the top begging for food.”

To demonstrate, Bill Cline puts his hand over a nearby tank of oscars — a few stocky, oval, mottled fish about five or six inches in length — and they immediately swim up to the surface of the water. Two of them snap at the air. “They’re very aware,” Cline says, “and they think they’re going to get fed. They’re not afraid of us at all.”

Craig Fries speaks up. “You can talk about the sociology of fish. You learn, when you keep fish, to incorporate the actual personalities, if you can believe that. All you have to do is say ‘personality’ to someone who isn’t a fish geek, and they laugh at you. But it’s very much a fact of what we do.”

No one disagrees with Fries.

“In fact,” says Kirk Bean, “that’s one of the great oddities of fish-keeping. For example, a 14-year-old boy might find piranha appeal to him a lot. They’re illegal in this state, and they have this nasty reputation. But they are, for the most part, one of the most boring fish in the whole entire world. Most people move beyond the desire to keep piranha, and then they’ll maybe get cichlids, which are typically much smarter, full of personality, and distinct, one fish to the next to the next. And therein lies a whole different way to appreciate what you’re keeping. You know, this isn’t just some toothy thing that eats. It’s now something that has an entire society within the tank.”

“You could almost call it politics,” adds Fries. “Some fish just don’t like each other. For whatever reason. And some do appreciate company. Some appreciate the company of other species.”

“And some are just happy when they see me,” says Bean, without a hint of irony. “That’s not a joke. And when someone else walks in, they’re not as happy.”

“Yeah,” agrees Fries, emphatically. “Yep, yep, yep. Exactly. Many people don’t appreciate the intellectual capacity of fish, but they are smart.”

“And smart comes in many forms,” adds Bean. “Some are better at communication. Some kinds of fish move better and work better together. Some are smarter in the ways that we would define smart, like, they seem more aware. And some are just much better predators, and their whole smartness, if you will, is associated with their ability to seek out and capture prey.”

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