1 Weakfish/sea trout—Cynoscion regalis (drum family - Sciaenidae)

Although it may sound fishy, Connaughton’s graduate journey began with a drum roll. He was doing research with the Delaware Department of Natural Resources and Environmental Control on the reproductive cycle of the weakfish—a commercially important fish that had been overfished. 

One evening, Connaughton was sitting in a boat with a gillnet gathering sample weakfish when he heard what he describes as thousands of bullfrogs. The noise was so loud, he could feel the vibrations through the hull. And when he pulled male fish from the net, he could feel them thrumming and hear the drum beat. He had no idea fish made sounds and was entranced.

Most studies of fish reproduction focus on the females—when, where, and how they spawn. He asked his thesis supervisor if he could focus on the sound display of the males. His supervisor agreed. Connaughton had found the subject for his thesis and dove in (pun intended).

He discovered that male weakfish have a sonic muscle that develops and atrophies at different stages in the reproductive cycle. The growth responds to increases in testosterone levels, which he was able to replicate in the lab. As males approach the spawning season, the muscle thickens and produces the drumming sound. This is used to call females to spawn. After the mating season, the muscle shrinks and the fish resume their silent lives.

Connaughton wrote his thesis on the male weakfish and earned his doctorate as a marine biologist.

2 Oyster toadfish—Opsanus tau (Batrachoididae)

Connaughton’s second fish is also a noise maker, the oyster toadfish. After getting his doctorate, Connaughton worked briefly in a lab in Texas with monkeys. It was not to his liking, and he jumped at the chance to return north and work with a researcher on oyster toadfish. Like weakfish, the male toadfish produces sound to attract females, but it also grunts to warn other males to stay away. 

“The toadfish is an unattractive little dude, which is one of the reasons I’ve got a soft spot for them,” Connaughton said. “They’re so ugly that I love them.”

The toadfish’s claim to fame is not its looks but the fact that its sonic muscle is the fastest muscle in the vertebrate world. It contracts at 200 hertz—that’s 200 times per second. In comparison, a hummingbird beats its wings at 60 hertz, and that’s too fast for the human eye to see. He assisted a researcher working on the cellular mechanism behind its sound-making muscle. The toadfish confirmed Connaughton’s calling as a marine biologist and provided him with his niche in the academic world—noisy fish.

3 Northern sea robin—Prionotus carolinus (Triglidae)

After the toadfish project, Connaughton got a grant to work on a solo project on another sound-making fish that’s also quite a looker.

“What’s fascinating about sea robins is that they look like a chimera,” he said, “like three or four different animals slapped together—crab legs, fins like robin’s wings, a head like a duck, and then there’s a fish body.”

Not only do they look odd, but they have adapted fins that look like legs and allow them to walk on the seafloor. If that isn’t enough, these “legs” allow them to taste as they walk across the floor and find food.

Like the toadfish, they produced a 200 hertz tone, but instead of muscles that contract at 200 hertz, they have 100 hertz contractions that alternate. The paper he wrote and published on this was the only paper he’s published as the sole author and marks his arrival as a researcher. 

4 Atlantic croaker—Micropogonias undulatus (Sciaenidae)

His sea robin research led to his appointment as an ecology professor at Washington College. As every young academic knows, as well as being a good teacher and mentor, you have to do original research to get tenure.

Connaughton considered researching the weakfish, the fish that had sparked his love of fish in the first place. Unfortunately, the weakfish doesn’t come close enough to Chestertown to be easily studied. So he chose another member of the drum fish family, the Atlantic croaker, as his research subject.

Over the years, the research he did on the croaker, often with Washington students, found that both sexes have sonic muscles. For most of the year, they are used to sound off when there’s danger. As mating season approaches, however, the males’ muscles grow while the females’ shrink. By the time mating begins, only the males are sounding off, and that’s to attract females. His extensive publications on the reproductive cycles and sound of the croakers earned him tenure at the College. 

5 Spotted eagle ray - Aetobatus narinari (Myliobatidae)

The last fish on his list is a silent creature far different from the others, yet it, too, marks a milestone in his career.

By the time Connaughton encountered the spotted eagle ray, not only had he studied fish sounds, but he had inadvertently become a great fish mimic (possibly the greatest in the world). That’s right, he can now talk fish!

He discovered this talent when presenting at a conference. He had his research slides and recordings of the fish prepared, but when it came to presenting in front of an audience, the audio didn’t work. The show had to go on. Connaughton stepped up to the mic and did all four of his favorite fish—the weakfish, toadfish, sea robin, and croaker. The audience clapped and clapped.

So, why then is a silent ray the final fishy milestone in his career? He accompanied Washington students on a study abroad trip to Belize. There, he had just surfaced from snorkeling when a colleague shouted at him to look behind him.

He turned, and one of the most beautiful animals he’d ever seen was gliding toward him—a spotted eagle ray.

“It’s a big enough animal, and it’s beautiful enough that you just sort of stop,” he said. “Has there ever been a moment when you’re just all in? Something happens, and you’re not thinking about anything else, you’re just here.”

In that moment, he had an epiphany: he was exactly where he should be—teaching at a college he loved, researching a subject he loved. He had arrived.

“I like the spotted eagle ray because of how it makes me feel,” he said. “I mean, it’s wonderous and serene. And sometimes beauty is enough.” 

—Darrach Dolan