Scientists Found New Bivalve Species in Japan

Scientists have discovered a new bivalve species that prefers living on the body surface of earthworm-like sea cucumbers.

Most of the bivalve species can be found in sand, mud or attached to rock surfaces. However, the newly discovered species of bivalve, described in a paper published in the journal ZooKeys, was found attached to the body of a sea cucumbers living in mudflats at the mouth of the Souzu River in southwestern Shikoku Island, Japan.

The new bivalve, dubbed as Borniopsis mortoni (Galeommatoidea), uses its foot and byssal threads to attach itself to the body surface of its potential host, an earthworm-like sea cucumber called Patinapta ooplax (Synaptidae). Reaching only up to 4.1 mm in length, B. mortoni is considered to be one of the smallest species of the genus.

B. mortoni is characterized by its elongated ovate shells covered by a tan to dark brown periostracum. Researchers believe that the small size of the B. mortoni is adapted to fit in the very narrow burrows of sea cucumbers, which is most likely used to shelter them from predators.read more