Reproductive System of Earthworm
Tutorspoint provides Reproductive System of Earthworm Homework Help. Earthworms are hermaphrodite, i.e., both testis and ovaries are present in the same individual. The 10th and 11thsegment consists of two pairs of testes, with their vas deferentia running up to the 18th segment, thus joining prostatic duct. One pair of accessory glands is present in each 17th and 19th segment. Four pairs of spermathecae are present in 6th-9th segment with one pair in each segment, thus storing sperms for copulation. The prostrate and the spermatic duct open in a pair of male genital pores present in the ventro-lateral side of the 18th segment.
In the 12th and the 13th segment, one pair of ovaries is attached to the inter-segmental septum. Just below the ovaries, the ovarian funnels continue to run as oviduct and join together to open into exterior on the ventral side as a female genital pore present in the 14th segment.
During copulation, a mutual exchange of sperms occurs through sperm packets called spermatophores. The mature egg and sperm cells along with nutritive fluid are deposited in a cocoons secreted by the glandular cells of clitellum. The cocoons containing the eggs fertilized by the sperms are slipped off through the body of the earthworm. These cocoons are then deposited in the soil to promote the fertilization and development of embryos. After about three weeks, the cocoons produce two to twenty offsprings. The development of baby worms is direct without any larval stage.