Reproductive system of gastropods

The reproductive system of gastropods (slugs and snails) varies greatly from one group to another within this very large and diverse taxonomic class of animals.

[4] Gastropods are capable of being either male or female, or hermaphrodites, and this makes their reproduction system stand out amongst many other invertebrates.

Within the main clade Heterobranchia, the informal group Opisthobranchia are simultaneous hermaphrodites (they have both sets of reproductive organs within one individual at the same time).

Phylogenetic evidence for this is present based on the overall condition of the gonads especially in the degree of development of the genital ducts.

The outer opening of the reproductive system is called the "genital pore"; it is positioned on the right-hand side, very close to the head of the animal.

The love-dart (if present) is produced and stored in the stylophore (often called dart sac) and shot by a forceful eversion of this organ.

[7] The female portion includes a fertilization pouch and posterior and anterior mucous glands, which open up into a pallial cavity which leads to a small muscular vagina.

The posterior vas deferens is followed by the prostate, and the anterior vas deferens flows through the haemocoele, an enlarged blastula filled with blood, of the head and opens into a muscular penis which is engulfed in a small portion of skin called the prepuce sac.

Gametes form in the ovotesties, an organ which produces both ova and sperm, and pass down into the hermaphroditic duct to the albumen gland, the junction of where the common duct splits to either vas deferens or oviduct, where they are stored until they are needed for either mating or self-fertilization.

It is believed that this junction acts as a regulatory mechanism via contracting muscles, to help direct sperm or eggs into the correct ducts.

[10] The sperm passes into the male duct, or vas deferens, where is receives secretory additions in the form of mucus from the prostate.

The ova then enter the albumen gland to get a nutrient dense mucus coating which serves to form the egg capsule.

[16] Additional reproductive structures include Females have a gonopore that is connected to a seminal receptacle.

The mantle tubule produces three things, yolk; carries most of the nutrients needed to develop a healthy offspring, egg capsule formation, and sperm reception and storage; where fertilization occurs.

The male and female system act as separate units until the egg and sperm are ready to fuse together.