There are 290 described species in the tube-dwelling family Sabellidae (Fauchald, 1977), but our knowledge of their reproductive biology is limited, in whole or in part, to no more than 30 species (McEuen, Wu & Chia, 1983; Knight-Jones & Bowden, 1984). In the monogeneric subfamily Myxicolinae, the diminutive Myxicola aesthetica (=dinardensis) (Claparède) is known to undergo scissiparity (Caullery & Mesnil, 1920; Okada, 1934; Knight-Jones & Bowden, 1984). For the larger species, M. infundibulum (Reinier), the only information on reproduction is: an illustration of the sperm (Claparede, 1870), the conclusion that it spawns during the autumn in the Bay of Fundy and adjacent waters (MacKay, 1977 a, b), and that autotomy has not been observed and regeneration is limited to the branchial plume (Wells, 1952).