SPERM ARE STORED IN THE OVARY OF LACUNA-(EPHERIA)-VARIEGATA (CARPENTER, 1864) (GASTROPODA, LITTORINIDAE)

Sperm are stored in the ovary of Lacuna (Epheria) variegata (Carpenter , 1864) between oocytes or oriented with follicle cells singly or in c lumps. The sperm develop close associations with follicle cells and in some cases become embedded in invaginations of cell apices. Follicle cells are rich in rough endoplasmic reticulum and are generally consid ered to provide nutrients to developing oocytes. The storage of sperm in the ovary was previously unknown for any gonochoric gastropod. The existence of sperm storage in the ovary of L. variegata has implicatio ns for both the site of fertilization and for sperm capacitation in th is genus. The subfamily Lacuninae represent a monophyletic clade compr ising five genera. This clade was previously characterized partly by a long duct to the seminal receptacle in two genera and by the eventual loss of the seminal receptacle with sperm storage in the oviduct in t hree others, including Lacuna. Storage of sperm in the ovary is an imp ortant new character that will enable further distinction among specie s of this unusual clade. (C) 1993 Wiley-Liss, Inc.