Reproductive System

Male Reproductive System : The male genital system consists of internal organs; paired testes; paired vas deferens; paired terminal ampoules and external organs; a petasma and a pair of appendix musculina

The testis, an unpigmented and transluscent organ, is composed of an anterior and five lateral lobes located in the cardiac region dorsal to the hepatopancreas under the carapace. The lobes are connected to each other at their inner ends and lead to the next organ, the vas deferens. The vas deferens arises from the posterior margin of the main axis of the testis and opens to the exterior through genital pores located medially on the coxopod of the fifth pereiopod.

Each vas deferens consists of four distinct portion; a short, narrow, proximal medial oprtion having a double fixture (median vas deferens); a relatively long narrow tube (distal vas deferens); and a muscular portion (terminal ampoule).

The terminal ampoul, abulbous structure, possesses a thick muscular wall lined with extremely tall columnar epithelial cells. It has two chambers internally; one containing the spermataphores and the other, calcareous material of slightly grey colour. The pair terminal ampoules opens at the base of the coxopod of fifth pereopods. The spermatazoan, a minute globular body, is composed of two part; head and tail.

The head is large and almost circular in outline, being about 3 microns in diameter, while the tail is relatively thick and short. Although it is logical to assume that the spermatozoan is capable of movement, it has never been observed.

The petasma is a pair of endopods of the first pleopods. It is formed by the interlocking of minute hook-like structures.

The shape of the appendix masculina which is located on the endopod of the second pleopod is generally oval.

The spermatophores, one from each terminal ampoule, become fixed together longitudinally at time of extrusion and are refered to then as the "compound spermatophores".

Spermatophore structure vary considerably among closed thelycum and open-thelycum shrimp, but mating and coutship rituals are similar within each group. Spermatophore among the open thelycum shrimp are quite complicated.

Female Reproductive System : The female reproductive system consists of paired ovaries, paired oviducts and a single thelycum; the first two are intern and the last os an external organ. The ovaries are partly fused, bilaterally symmetrical bodies extending in the mature female for almost its entire length, from the cardiac region of the stomach to the anterior portion of the telson.

In the cephalothoracic region the organs bears a slender anterior lobe and five finger-like lateral projection. A pair of lobes, one from each ovary, extends over the length of the abdomen. The anterior lobes lie close to the esophagus and cardiac region of the stomach. The lateral lobes are located in the large mass of hepatopancreas and ventrally in the pericardiac chamber. The abdominal extensions lie dorso-lateral to the inestine and ventro-lateral to the dorsal abdominal artery.

The oviduct orginate at the tips of the sixth lateral lobes and descend to the external genital aperture hidden in the earlike lobes of the coxopods of the third pair of periopods.

The thelycum is located between a pair of fifth pleopods and consists of an anterior and a pair of lateral plates.