In between them a cardio-pyloric strand, connecting heart to pyloric stomach is situated. Histologically, each testes consists of a coiled and thin walled serriiniferons tubules embedded in connective tissue.
Each tubule is lined with germinal epithelium, the cells of which undergo spermatogenesis to form spermatozoa. A mature sperm consists of a large nucleus and a tail like blunt process.
A long coiled and narrow tube, the vasa deferens arises from each testis near its posterior end. They form a coiled mass and run downwards between the abdominal flexor muscles on the inner side and thoracic wall on the outer side.
Near the base of fifth leg vas deferens swells to form a club-shaped vesicula seminalis. They store spermatozoa in the form of white compact bodies called spermatophores.
They open outside through male genital pore situated on the inner side of coxa of fifth walking leg of its side.
Female Reproductive System
The two ovaries are white compact and sickle-shaped bodies touching each other at both the ends but leaving a gap in the middle for the passage of the cardio-pyloric strand.
The size and shape of ovaries vary with age and the season of year. Each ovary is enclosed within a membranous capsule and is made of numerous radial rows of ova in various stages of development. Mature eggs are centrolecithal.
A short, wide and thin walled tube, called the oviduct, originates from the outer middle border of each ovary.
It opens outside through a female genital aperture on the inner side of the coxa of third walking leg of its side.
Life history and development :
The breeding season of Prawn occurs during May, June and July. The male deposits spermatophores near the genital opening of the female and the eggs get fertilized as they come out.
Thus fertilization is external or in-situ. After fertilization eggs remain attached to the pleopod through the sticky secretion of certain tegumental glands. During breeding season a female carries the bunches of eggs in this way until they hatch.
Development is direct and the juveniles hatching out of the eggs resemble the adult except in size. It takes 5 to 6 weeks and juveniles remain cuing to pleopods and undergo moulting and growth.