Leech is hermaphrodite, both the male and female reproductive organs are present in the same.
Male Reproductive system : There are eleven pairs of testes, one pair in each segment from 12 to 22 segments. They are in the form of Spherical Sacs called testes sacs. From each testis arises a short duct called Vas efferens, which join with the Vas deferens. The Vas deferens becomes convoluted to form the epididymis or sperm vesicle, to store spermatozoa.
The epididymis leads to a short duct called ejaculatory duct. The ejaculatory duct on both sides join to form Genital Atrium. The Atrium consists of prostate glands and the Penial sac, with Penis, that opens through genital pore.
Female Reproductive system: It consists of Ovaries, Oviducts and Vagina. Each ovary is coiled, ribbon shaped, and the single pair of ovary is the `11^("th")` segment. The Ova are
Reproductive system of Leech budded off from the ovary. From each ovary runs a short oviduct, and the oviducts of two sides joins together, to form a common Oviduct, which opens into a pear shaped Vagina. Vagina lies mid ventrally in the posterior part of `11^("th")` segment.
Internal fertilisation takes place. This is followed by cocoon formation. The cocoon or egg case is formed around `9^("th"),10^("th")` and `11^("th")` segments. Development is directs, proceeds in cocoon, which contain one to 24 embryos. The emerging young leech, resembles the adult Leech.
