ALIMENTARY AND REPRODUCTIVE SYSTEMS OF OXYCHILUS CELLARIUS (MÜLLER) (STYLOMMATOPHORA)

Abstract

Detailed study of the life cycle and the anatomy, histology and functioning of the alimentary and reproductive systems of Oxychilua cellariua (Müller) lead one to regard this snail as a typical and relatively unspecialized member of the Stylommatophora. Feeding currents within the oesophagus and staomach have been examined during dissection of fresh specimens and the form of the stomach region has been homologized with that of more primitive gastropods. Histochemical methods have been used to determine the nature of cell contents and secretions along the reproductive tract and the possible part played by these substances during copulation and egg‐laying has been investigated. The path used by sperm prior to, and following, copulation has been traced. Comparison is made with members of the higher Basommatophora, the Hygrophila. Much greater structural and functional differences become apparent between members of the Stylommatophora and the Basommatophora than have hitherto been suspected.

The functional significance of the spermatophore and the fate of spermatozoa in the genital tract of Helix pomatia (Gastropoda: Stylommatophora)

“…These blind sacs are generally assumed to function as a spermatheca ( = receptaculum seminis) storing foreign sperm, even though a functional distinction between the pouch and the sacs has not been pointed out (Perez, 1868;Meisenheimer, 1907;Baecker, 1932). The same function has been proposed for a similar structure in other stylommatophoran snails, Oxychiius and Succinea (Rigby, 1963(Rigby, , 1965. The blind sacs are also found in Cepaea and Arianta, and in all species mentioned contain oriented spermatozoa (Plate I(a)).…”

“…As suggested by Rigby (1963Rigby ( , 1965, breakdown products of sperm may be taken up by the epithelium of the bursa. This certainly accounts for some of the ingested matter (see p. 48).…”

“…In some opisthobranchs and stylommatophoran pulmonates another function of the bursa has been suggested. Sperm are deposited in the stalk or in the vagina and migrate from there, and it seems that in the bursa secretions with digestive properties deal with superfluous sperm and different kinds of debris from the reproductive tract (Eales, 1921;Lemche, 1956;Fretter & Graham, 1964;Rigby, 1963Rigby, , 1965.…”

“…The morphology of the genital tracts and their function in conducting and storing sperm are associated with the function of the spermatophore. The most detailed accounts of these subjects are found in the papers by Meisenheimer (1907Meisenheimer ( , 1912, Baecker (1932) and Breucker (1964), and, concerning other Stylommatophora, Hyman (1967), Hofmann (1923) and Rigby (1963Rigby ( , 1965. Some new facts on the "biology" of sperm are presented and discussed in relation to the function of the genital organs and the spermatophore.…”

How can two soft bodied animals be precisely connected? a miniature quick‐connect system in the slugs, Arion lusitanicus and Arion rufus

“…3l). In both species, the eversion of the posterior lip is probably not mediated by pressure of the hemo-lymph, but can be explained by the existence of spongious tissue (Trappmann, 1916;Baecker, 1932;Rigby, 1963) at the base of the posterior lip which is filled and expanded as soon as it leaves the genital aperture. Consequently, the wall of the proximal atrium (pa) is shortened and leads to the movement of the e/pd-complex distally into the direction of the genital aperture ( Figs.…”