November 2, 2024

Hidden in Plain Sight: Marine Biologists Discover New Clam Species in South Africa

Hidden In Plain Sight: Marine Biologists Discover New Clam Species In South AfricaBrachiomya ducentiunus - Hidden In Plain Sight: Marine Biologists Discover New Clam Species In South Africa
A comprehensive study led by Paul Valentich-Scott from the Santa Barbara Museum of Natural History has uncovered new aspects of galeommatoidean bivalves in South Africa. The research reveals a new species and highlights the unique symbiotic relationships these bivalves maintain with sea urchins. The findings enhance our understanding of marine biodiversity and emphasize the need for the conservation of these lesser-known marine organisms. The image above depicts the newly discovered species, Brachiomya ducentiunus, crawling on a sea urchin spine. Credit: Craig Foster

Researchers discovered a new species of marine bivalve in South Africa, providing new insights into the biodiversity of the region and emphasizing conservation.

Galeommatoidean bivalves are a highly diverse, yet poorly known, group of marine mollusks. Now, a study led by Paul Valentich-Scott from the Santa Barbara Museum of Natural History, along with collaborators from the University of Cape Town, Sea Change Trust, Stellenbosch University, and the University of Colorado Boulder, has uncovered new insights into the habitats, symbiotic relationships, and taxonomy of these fascinating animals.

Discovery of New Species

In the study, recently published in the scientific journal ZooKeys, the researchers collected four species of galeommatoidean bivalves collected from the Western Cape region of South Africa. Among these is one new species, Brachiomya ducentiunus. This small clam, which is only 2 mm (less than 1/8th inch) in length, spends its life crawling between the spines of sea urchins.

The new species has so far only been found in one locality in False Bay, South Africa, where it was found attached to the burrowing sea urchin Spatagobrissus mirabilis in coarse gravel at a depth of about 3 m. It has not been observed free-living, without the host urchin.

Brachiomya ducentiunus was discovered while preparing and working on the 1001 Seaforest Species project, a research and storytelling program aimed at increasing awareness of regional kelp bed ecosystems colloquially referred to as ‘the Great African Seaforest’.

Brachiomya ducentiunus Crawling on Sea Urchin - Hidden In Plain Sight: Marine Biologists Discover New Clam Species In South AfricaBrachiomya ducentiunus Crawling on Sea Urchin - Hidden In Plain Sight: Marine Biologists Discover New Clam Species In South Africa
Dozens of Brachiomya ducentiunus crawling on the surface of a sea urchin. Credit: Charles Griffiths

Impact on Biodiversity Knowledge

“This study marks a significant advancement in our understanding of the biodiversity and ecological interactions of galeommatoidean bivalves,” says Valentich-Scott. “By uncovering the hidden lives of these small but ecologically important organisms, we hope to contribute to the broader knowledge of marine biodiversity and the conservation of these unique habitats.”

Importance of Regional Marine Research

Co-author Charles L. Griffiths, emeritus professor at the University of Cape Town, says, “A large proportion of smaller marine invertebrates remain undescribed in western South Africa and almost any project that samples specialized habitats turns up many new records and species.”

In a similar vein, co-author Jannes Landschoff, a marine biologist at the Sea Change Trust, says “Creating foundational biodiversity knowledge is a most important step to the humbling realization of how fascinating and uniquely diverse a place is. I see this every day through our work in the rich coastal waters of Cape Town, where an extensive underwater kelp forest, the ‘Great African Seaforest,’ grows.

Reference: “Bivalves of superfamily Galeommatoidea (Mollusca, Bivalvia) from western South Africa, with observations on commensal relationships and habitats” by Paul Valentich-Scott, Charles Griffiths, Jannes Landschoff, Ruiqi Li and Jingchun Li, 22 July 2024, ZooKeys.
DOI: 10.3897/zookeys.1207.124517