URI Marine Biologist, Dr. Jacqueline Webb, sounds off about research into butterflyfish communication
By RUDI HEMPE
CELS News Editor & Reporter
Butterflyfish are colorful denizens of the world’s coral reefs and also of many a home aquarium but to some people like Dr. Jacqueline Webb, URI marine biologist, they are a feast for the ears as well as the eyes.
 Webb, who arrived at URI from Villanova last summer, spent the last eight years researching the anatomy of butterflyfish, work that recently was referenced in an article posted on Science NOW, the online site of Science published by the American Association for the Advancement of Science.
The article, entitled “The Talk of the Sea,” describes how butterflyfishes communicate with each other with a variety of sounds. Butterflyfish are somewhat unique beyond their visual attractiveness—they are monogamous, gregarious and territorial.
Webb’s research on butterflyfish started when a colleague of hers, Dr. Stanley D. Blum of the California Academy of Sciences, was doing a systemic revision of all of the butterflyfishes.
“He told me that all members of only the genus Chaetodon have an opening on the inside surface of a small bone (the supracleithrum) at the rear of the skull,” she said, and he suggested she research this anatomy to find out what its function might be.
She immediately went to a pet store and bought a Chaetodon octofasciatus to study. After analyzing the anatomy in 22 butterfly fish species, she determined that there were six anatomical variations on a unique association of this bone opening with the swim bladder.
Two “horns” from the swim bladder project up into the fish’s head and approach or come in contact with one of the “lateral line canals” which contain
small sensory organs that can detect nearby motion in the water. Webb thinks that the horns press on soft tissue that fills the opening in the supracleitheral bone allowing the transmission of
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sounds to the lateral line system. If true, this would be very rare among fishes. The swim bladder is an air-filled organ that provides fishes with buoyancy and also serves to amplify sound and transmit it to the ears. Most fishes have swim bladders but only one genus of butterflyfishes has this association of the swim bladder horns and the lateral line canals.
Several years ago, marine biologist Tim
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intense field study of this fish group over several decades, says Jacqueline Webb a URI marine biologist. The findings underscore the need ‘to consider the sound dimension of reef communities when contemplating not only the behavior and ecology of animal populations, but the increasing impacts of human noise on the underwater environment.’ ”
Webb notes that other fish have
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Tricas of the University of Hawaii, discovered that these fishes produce sound, providing support for Webb’s hypothesis that this unique anatomy might be an adaptation for amplifying and transmitting sound to the lateral line system In the Science NOW article, Noreen Parks describes Tricas’ research into the nature of the sounds produced by butterflyfishes. He conducted an underwater experiment by putting a pair of butterflyfishes in a glass bottle and placing the bottle in the territory of another pair of butterflyfishes of the same species. The results, wrote Parks, “revealed territory defenders aggressively charging the intruders, while making rapid, sound-generating moves, such as flicking and erecting their fins, jumping and turning. In response, the bottled fish grunted repeatedly. Only paired fish grunted—not single individuals—so Tricas suspects grunts are distress signals to mates.”
Writer Parks continued “The connections between sound production and social behavior had gone unnoticed despite |
enhanced hearing—herring and their relatives, minnows and all catfish.
Webb who is currently setting up her lab in the Biological Sciences Center said she is thrilled to come to URI with its proximity to Narragansett Bay. Her research on butterflyfishes will continue but she also hopes to focus on sensory biology of species of fish in the bay. “There’s a lot of anatomy that still needs to be studied,” she says.
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