Alternate Title

A Commensal Relationship Between a Foraminifer and a Bivalve Mollusk

Document Type



During June, 1960, the M/V Hermes of the Gulf Coast Research Laboratory made several trawl hauls south of Horn Island, Mississippi. One haul was made June 27 at a depth of 20 m. on sandy mud botton at 30°04’30” N., 88”36’ W., or about 10 nautical miles south of Horn Island. A considerable number of animals, including starfish, hermit crabs and tube worms, were caught in the trawl. Pieces of the parchment-like worm tube of Chaetopterus variopedatus (Renier) were caught in the meshes of the net and were also collected.

A small bivalve mollusk, Notocorbula operculata (Philippi 1848) was found to be attached to most of the Chaetopterus tubes. Microscopic examination showed that the bivalves were attached at the anterior ventral margin with a byssal thread. This little clam has been found under similar conditions at Dry Tortugas, Florida (Harvey R. Bullis, Jr., personal communication). It has been reported as abundant in 22-65 m. of water on mud bottom along the entire northern coast of the Gulf of Mexico (Parker 1960). It was also noticed that a single species of Foraminifera was attached to many of the clams. The attachment was not very strong, seeming to consist merely of a weak cement holding the ventral surface of the foraminifer to the bivalve shell, nor was it confined to a particular area on the bivalve, but occurred in any position on either valve.

First Page


Last Page