Make your own free website on Tripod.com
Reproduction

Pomatias elegans and other Prosobranchs have seperated sexes but most snails are hermaphroditic(having both male and female reproductive organs). Although this means that in theory they can mate with themselves,they hardly do this in nature.As long as there are other snails around,they will always mate with another individual. The Prosobranchs have simple reproductive organs.Males have a gonad,a vas deferens and a penis.The females a gonad, an oviduct and a vagina. The Pulmonates are hermaphroditic and their reproductive apparatus is more complex.The gonad is an ovotestis producing both eggs and sperm. The duct is divided, one channel for transporting eggs and another for sperm. Snails have an extensive mating ritual which involves circling around,and then riding up to eachother.They touch eachother with their foot, tentacles and genital organs. This takes usually about an hour,the actual mating can easily last eight hours. Photo:The living world of mollusks Each snail has two sets of sex organs.One with a penis,testes and sperm and the other with ovaries,eggs,an oviduct and a pouch or receptacle for storing sperm of another snail. The penis is located at the base of the right tentacle,close to the vagina. In some species,like Cornu aspersum(Helix aspersa),little chalky darts or love darts are shot into eachothers bodies.This doesn't happen always however. Recent research (Koene and Schulenburg 2004)has shown that an allohormone in the mucus on the dart makes digestion of the sperm cells more difficult. This way more sperm cells can reach the spermathecae. The sperm is transferred in so-called spermatophores which are exchanged between the snails. Schematic morphological drawing of the reproductive morphology of a land snail with one dart and a diverticulum. The love-dart (D) is produced and stored in the stylophore (S, often called dart sac) and shot by a forceful eversion of this organ. The mucus glands (MG) produce the mucus that is deposited on the dart before shooting. The penis (P) is intromitted to transfer the spermatophore. The sperm container is formed in the epiphallus (EP), while the spermatophore's tail is formed by the flagellum (FL). When a bursa tract diverticulum (BTD) is present, the spermatophore is received in this organ. Together with the bursa tract (BT) and bursa copulatrix (BC) these form the spermatophore-receiving organ (SRO, indicated in grey), which digest sperm and spermatophores. Sperm swim out via the tail of the spermatophore to enter the female tract and reach the sperm storage organ (SP, spermathecae) within the fertilization pouch (FP)-spermathecal complex. Other abbreviations: AG, albumen gland; G, genital pore; HD, hermaphroditic duct; OT, ovotestis; PRM, penis retractor muscle; SO, spermoviduct; V, vaginal duct; VD, vas deferens. [from:Shooting darts: co-evolution and counter-adaptation in hermaphroditic snails by J.M.Koene and H.Schulenburg]

After about two weeks the eggs are laid,although in some species,the seminal fluid can be stored for up to year.The eggs look like little white pearls and are laid seperatly or in groups under stones,logs or fallen leafs.After a few weeks tiny snails are born. They have a transparent shell. Some snailspecies are ovo-viviparious,this means that the eggs hatch inside of the snail,and tiny snails are born. from:weichtiere.de

Most species reach maturity in a year,but the larger ones can take two to four years to reach maturity.

To main page To biology of snails