VCU biologist studies noisy fish

Michael Fine plucked a 10-inch catfish from its tank and gently tugged at a fin in hopes of getting it to talk.

The fish had nothing to say.

And then....

"He just made a sound!" said Fine. "He's doing it again!"

The message was barely a whisper, undetectable a few feet away amid the rumble of fish tanks and pumps.

The catfish gazed at nothing with an otherworldly face featuring whisker-like barbels, bulbous eyes and gaping mouth.

"C'mon, Bub," Fine said. "He's not doing it now."

He was a fish of few words.

That was fine with Fine. He had heard it all before. The Virginia Commonwealth University biologist is an authority on fish sounds.

"With a lot of people, it doesn't occur to them that fish can make sounds," said Fine. "It's a minority of fish that do it, but it's not rare."

And sounds — even the little catfish's protests — travel much better in water than air.

So much for Jacques Cousteau's "Silent Word."

Fine is an easygoing, bearded, bespectacled man with a tangle of Einsteinian hair that is way too brown for his 65 years.

"Mike is an international expert on sound production by fish," said Leonard A. Smock, director of VCU's Rice Center for Environmental Life Sciences. His work "has considerable implications to understanding the evolution of fish."

On the practical side, experts say fish-sound research could produce information of use to people from Navy submariners to dredge operators trying to avoid spawning fish.

Work such as Fine's sheds light on an underwater world "that we humans can only visit briefly and never appreciate fully," said Greg Garman, a VCU fish ecologist.

Fish typically make their grunts, croaks, snaps, clicks, trills and drumming sounds to attract mates and defend territories. But experts don't understand all the reasons in all noisy fish.

Fish such as croakers, toadfish and black drums – note the names – can make their swim bladder, the sac that regulates buoyancy, vibrate like a speaker.

Some herrings seem to communicate by passing gas.

Fine has found that channel catfish send an apparent distress signal — a froglike "Reep! Reep!" — when being swallowed by largemouth bass. The call might be a way of attracting more predators.

And why would the fish want more predators? "If you are in somebody's mouth, and another predator comes, maybe they'll start fighting over you, and you have a chance of escaping," Fine hypothesized.

Most fish-sound research is aimed at salt water. Over the past few years, Fine has explored sounds made by catfish that inhabit tidal fresh water, specifically the James River below Richmond.

"Fresh water has been largely neglected," Fine said.

Fine has done the work primarily in his lab, or with captive fish in the James. This spring, he and a student will put an underwater microphone, or hydrophone, in the James at Charles City County to see what sounds they pick up.

He doesn't know if he will hear an occasional call or a concert.

Fine primarily studies channel catfish, like the one in the tank, and blue catfish, which were stocked in the James in the 1970s and now can easily top 50 pounds.

Scientists fear that noise from sonar and ships could be hurting whales, dolphins and some fish in our oceans. VCU's Garman speculated that the huge blue catfish might be drowning out native Virginia fish "like an outdoor rock concert next to a poetry reading."

A catfish makes a sound by moving its pectoral, or front, fins out like wings. A ridged bone at the base of the fin rubs against the pectoral girdle, a bone that wraps under the fish's front end like an upside-down saddle. That girdle amplifies the sound like a speaker. The effect, Fine said, is like bowing a violin with a Ruffles potato chip. Who knew catfish were so talented?

Why some fish developed sounds and others did not is a mystery of evolution. Maybe a fish will tell us someday.