University of Guam professor of ichthyology Terry Donaldson, Ph.D. has recently co-authored a paper on bioacoustic communication within the family Holocentridae, a group of marine fishes commonly known as squirrelfishes and soldierfishes. These fishes are known to communicate by sound production.
Donaldson also leads the largest research grant in UOG history, the National Science Foundation Established Program to Stimulate Competitive Research (Guam NSF EPSCoR) as Principal Investigator and Project Director.
Published in November 2024 in the journal Nature, the paper, entitled “Sounds as taxonomic indicators in holocentrid fishes,” is the first large-scale phylogenetic investigation on fish bioacoustics in this family. The study, which can be accessed here, examines whether it is feasible to use sounds for taxonomic identification of species within the family.
According to the study, holocentrids produce sounds through the “contraction of paired bilateral sonic muscles originating on the skull and inserted on articulated ribs in tight connection with the swim bladder.” These contractions produce vibrations that are amplified by the swim bladder.
All 73 species that were investigated had certain characteristics that made this family ideal for this study. This is especially important because holocentrids are nocturnal and rely heavily on vocal communication in the dark.
From May 2019 to July 2022, almost 400 specimens were collected in the coral reef areas of Guadeloupe, French Polynesia, Guam, Seychelles and Philippines. Sounds of the specimens were recorded while the fish were hand-held in the field, rather than in tanks, to minimize artifacts ((false signals not generated by the fish but rather picked up in the recording process) and provide the most reliable sound comparisons. The fish were then measured and photographed.
The portion of the research that took place on Guam was supported in part by an award from Guam NSF EPSCoR.
While species-specific sounds of animals have been extensively documented, there is limited phylogenetic research on acoustic behavior of fish species.
Fish are able to communicate through rubbing their pharyngeal teeth back and forth or through muscular contractions. The sounds that are created vary by species and can range from grunts to clicks to thumping noises.
“It’s possible to suggest that no two species make the same exact sound, even though they’re closely related,” said Donaldson. “They may have components that are the same but there’s something slightly different here or something radically different if you go from one genus to the next.”
This study demonstrates that sounds can indicate different taxonomic groups, although this depends on taxonomic level (i.e. family, genus or species). It was found that the higher the taxonomic level, the easier it was to differentiate them based on sounds.
The paper was written by Marine Banse with contributions from Eric Parmentier, who conceived and supervised the study, Donaldson, Estelle Bertimes, David Lecchini and Frederic Bertucci.
Donaldson has also co-authored, with Banse, Parmentier, and others, a publication based on a smaller study that describes acoustic communication in the relationship between nine species of squirrelfish in their relationship with cleaner fish. “Production of sounds by squirrelfish during symbiotic relationships with cleaner wrasses,” published in May 2024, observes the ability of the squirrelfish to communicate their desire to be cleaned through acoustic signals.
Both articles have been published in Scientific Reports, an open access journal that publishes original research in the areas of natural science, psychology, medicine, and engineering.
