Development in the genus Diopatra has been reviewed and divided into four patterns, ranging from brooding in the parental tube to presumed broadcast spawning (Paxton, 1993). While some information is available for numerous species, the identity of some is uncertain, or the information is only anecdotal. Only three species have been studied in detail. Eggs of D. cuprea are released in a jelly mass that readily dissolves in sea-water (Allen, 1959). Although natural spawning has not been observed for D. neapolitana, Cazaux (1972) was able to fertilize the eggs artificially and culture the larvae. The larvae of both species are lecithotrophic and free-swimming, indicating that they are broad-cast spawners.