Ultrastructure of the reproductive system of the black swamp snake (Seminatrix pygaea): Part I. Evidence for oviducal sperm storage

Oviducal sperm storage in the viviparous (lecithotrophic) colubrid snake Se minatrix pygaea was studied by light and electron microscopy. Out of 17 adu lt snakes examined from May-October, sperm were found in the oviducts of on ly two specimens. In a preovulatory female sacrificed 14 May, sperm were fo und in the oviducal lumen and sperm storage tubules (SSTs) of the posterior infundibulum. In a nonvitellogenic female sacrificed 9 June, sperm were fo und in the lumen and glands of the posterior uterus and anterior vagina, in dicating a recent mating. The glands in the posterior infundibulum and vagi na were simple or compound tubular, whereas glands in the uterus always wer e simple tubular. The epithelium of the sperm storage glands was not modifi ed from that lining the rest of the oviduct. The cuboidal or columnar epith elium consisted of alternating ciliated and secretory areas. The secretory product released into the lumen by a merocrine process contained mucoprotei n. Lipid droplets also were numerous in the epithelium. Portions of sperm s ometimes were embedded in the apical cytoplasm or in secretory material. A carrier matrix containing a mucoid substance, desquamated epithelium, lipid s, membranous structures, and possibly phagocytes was found around sperm in the posterior uterus. J. Morphol. 241:1-18, 1999. (C) 1999 Wiley-Liss, Inc .