Shellfish Breeding and Hatchery Management (2+1)

3.1.4 Male reproductive organ - external and process of gamete transfer

3.1.4 Male reproductive organ and the process of gamete delivery

Male reproductive system externally consists of a pair of pleopods as accessory reproductive organ, present on the inner side of the abdominal flap. The ejaculatory ducts of the testes open into a small gential papilla at the base of the 3rd pair of the walking legs.

The first pair of pleopod of the shrimp is made up of two segments, the basal one is broad, rectangular and flattened and positioned close to the sternal wall and the terminal one is long tube-like and tapering towards the tip. During mating with the female shrimp, this tip is inserted into the seminal receptacle of the female. The second pleopod helps in passing the spermatophores from the ejaculatory ducts into the funnel-like portion of the first pleopod.

The ejaculate from the gonad (testes) consists of non-motile sperms and seminal plasma. Sperms are enclosed in numerous small spermatophores and stored in the anterior vas deferens (vd), while the seminal plasma is produced and stored in the posterior vas deferens.