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

Abstract

Oviducal sperm storage in the viviparous (lecithotrophic) colubrid snake Seminatrix pygaea was studied by light and electron microscopy. Out of 17 adult snakes examined from May-October, sperm were found in the oviducts of only two specimens. In a preovulatory female sacrificed 14 May, sperm were found in the oviducal lumen and sperm storage tubules (SSTs) of the posterior infundibulum. In a nonvitellogenic female sacrificed 9 June, sperm were found in the lumen and glands of the posterior uterus and anterior vagina, indicating a recent mating. The glands in the posterior infundibulum and vagina were simple or compound tubular, whereas glands in the uterus always were simple tubular. The epithelium of the sperm storage glands was not modified from that lining the rest of the oviduct. The cuboidal or columnar epithelium consisted of alternating ciliated and secretory areas. The secretory product released into the lumen by a merocrine process contained mucoprotein. Lipid droplets also were numerous in the epithelium. Portions of sperm sometimes were embedded in the apical cytoplasm or in secretory material. A carrier matrix containing a mucoid substance, desquamated epithelium, lipids, membranous structures, and possibly phagocytes was found around sperm in the posterior uterus.

Ultrastructure of the reproductive system of the black swamp snake (Seminatrix pygaea). VII. spermatozoon morphology and evolutionary trends of sperm characters in snakes

“…This is the seventh paper in a series that describes the reproductive morphological characteristics of this natricine snake from the south‐eastern United States. Previous papers have included female sperm storage location (Sever and Ryan 1999), the oviducal cycle (Sever et al. 2000), renal sexual segment cycle (Sever et al.…”

Reproductive biology of Philodryas patagoniensis (Snakes: Dipsadidae) in south Brazil: Female reproductive cycle

“…The uterine glands have an important role in the development of eggs, providing the pseudokeratin, which is a component of egg shell membranes (Perkins & Palmer, 1996). Sperm-storage structures in the UVJ have been described as highly unspecialized and not differentiated glands from the oviduct epithelium (Sever & Ryan, 1999) that physically protect the sperm from getting caudally swept in the oviduct by the eggs (Aldridge, 1992). Females had sperm groups stored in furrows of the UVJ during all the seasons, but in higher frequency from winter to summer (July-March).…”

Ultrastructure of the reproductive system of the black swamp snake (Seminatrix pygaea). V. The temporal germ cell development strategy of the testis

“…The female reproductive system follows a prenuptial pattern of egg development, where eggs are produced after emergence from hibernation in the early spring (Seigel et al . 1995; Sever and Ryan 1999). Therefore, asynchrony exists between the female and male production of viable gametes because male black swamp snakes have a postnuptial development where spermatozoa are produced over the summer months and spermiated to the epididymis and ductus deferens between July and October This difference in gamete production is not unheard of in reptiles (Licht 1984) and facilitates the need for sperm storage (Gist and Congdon 1998; Sever et al .…”

“…2002). Indeed, sperm storage occurs in the male ductus deferens/ampulla (Sever 2004) and within sperm storage tubules (SSTs) in the oviducts of female black swamp snakes (Sever and Ryan 1999).…”

“…The testicular samples used here are from tissues collected and used in a sequence of articles detailing the ultrastructure of the black swamp snake's reproductive system (Sever and Ryan 1999; Sever et al . 2000, 2002; Sever 2004).…”