Observations on the Reproduction of Modiolus Modiolus in Isle of Man Waters

Abstract

The horse-mussel Modiolus modiolus (L.) is a bivalve molluse inhabiting coastal marine environments down to about 200 m, where it may occur in very large communities (Wiborg, 1946; Tebble, 1966; Comely, 1978). It can also be found low in the intertidal zone where it lives in rock pools or in the hold-fasts of Laminaria (Wilson, 1977; Davenport & Kjørsvik, 1982). It is a boreal species. In the Atlantic it ranges from the White Sea to the Bay of Biscay, off Iceland, the Faroes and down the east coast of North America to North Carolina. In the Pacific it occurs from the Bering Sea to Japan and California (Wiborg, 1946). Comparatively little work has been done on Modiolus modiolus, probably because it is of little commercial importance and lives predominantly subtidally in relatively inaccessible environments.