Receptaculum seminis

The receptaculum seminis (also known as semen bag, spermatheca or spermatheca) is a sperm storage bag and belongs to the genital apparatus of many female or hermaphrodite animals and is used to collect and store sperm from sexual partners . Molluscs (Mollusca) as the screw (z. B. Snail ) and arthropods (Arthropoda), all kinds of insects , arachnids and crustaceans , but also zwittrige orders as the segmented worms (annelids) and the flatworms have (Platyhelminthes) a such a seed bag.

The sperm can be carried in the body for a long time without fertilization . Alternatively, the sperm can fertilize several egg cells over a longer period of time without copulating again . In hermaphroditic animals, the location of the ducts often prevents their own sperm from entering the receptaculum seminis from the testes , e.g. B. by the seminal canals converging just before the genital pore .

Anatomy and fertilization process in spiders

The sperm library is located in the abdomen of the female animal. It can be one-piece or two-piece, also have an indentation and bulge, or be in pairs.

The structure of the genital organs and the fertilization of some real spiders is more complex . The haplogynen spinning the sperm pouch opens a fertilization program in the external uterine uterus externus . In entelegynous spiders , a sclerotized plate with a genital opening in the epigastral groove is located above the spermathec as a rather complex copulation organ.

two-part sperm library of the red chile tarantula ( Grammostola rosea )
one-part, branched sperm library from Acanthoscurria geniculata

When mating, the male inserts his genitals into the genital opening and releases his sperm . The sperm are stored in the receptaculum seminis until they are squeezed out again to fertilize the eggs that slide by. At the receptaculum seminis there is a fertilization pocket in which the actual fertilization takes place, as the egg cells migrate there from the ovary .

particularities

Indicoblemma lannaianum , a spider of the Tetrablemmidae family, can store sperm from different males for a longer period of time and release it to an external uterus in a controlled manner.

The sperm library of arachnids is skinned with each molt. The female must mate again after each moult in order to be able to release fertilized eggs.

Human anatomy

In women, it refers to the back of the vagina where the sperm lies after ejaculation .

supporting documents

↑ Rainer F. Foelix: Biology of the spiders. Georg Thieme Verlag, Stuttgart 1979, ISBN 3-13-575801-X .
↑ M. Burger et al.: Complex genital system of a haplogyne spider (Arachnida, Araneae, Tetrablemmidae) indicates internal fertilization and full female control over transferred sperm. In: Journal of Morphology. 267 (2), 2005, pp. 166-186, doi : 10.1002 / jmor.10394 .

[1] Rainer F. Foelix: Biology of the spiders. Georg Thieme Verlag, Stuttgart 1979, ISBN 3-13-575801-X .

[Burger_et_al-2] M. Burger et al.: Complex genital system of a haplogyne spider (Arachnida, Araneae, Tetrablemmidae) indicates internal fertilization and full female control over transferred sperm. In: Journal of Morphology. 267 (2), 2005, pp. 166-186, doi : 10.1002 / jmor.10394 .