Comment upon the gametic exchange in earthworm during mating. Discuss the physiology in reproduction of earthworm.

Explanation

Reproduction is a unique process in earthworm. Earthworm is a bisexual animal. Matting takes place in monsoon in earthworms and its done after maturity of sperm cells. Exchange of reproductive cells and mating during physiological process of reproduction can be described as per below. (i) Earthworms are protandrous (e.g. sperm cells become adult before egg cell becomes mature) (ii) M ating occurs by external fertilization in earthworm. (iii) During mating exchange of sperm cells occur between two earthworms. (iv) Both the earthworms take out their half bodies from near by burrows and opposite genital pores exchange amount of sperm cells. It is called spermatophores (v) During this process, skin surrounding male genital pore raises and forms temporary papillae which like penis enter into spermathecal pore and keeps it open. (vi) One spemathecae gets filled then earthworm performing reproduction (go further and come against male) genital pore of another spermathecae. This process gets completed after one hour of mating. (vii) Spermcells mainly resides in Diverticula in spermatheace while Ampule is associated with the secretion of nutrients for sperm cells. (viii) Sperm cells and egg cells enter into cocoon which is secreted by clitelum gland. (ix) Thus fertilization takes place in earthworm by external and fertilization by an agent.