Embryonic Development of Commercially Important Portunid Crab Portuns sanguinolentus (Herbst)

In the present study an attempt was made to study the embryonic development of commercially important crab Portunus sanguinolentus. The newly spawned eggs were round and golden yellow in colour. The undeveloped and mass of undifferentiated cells were also found in the berry. The yolk granules were denser. The cleavage and gastrulation were not clear. The diameter of the freshly laid egg was 0.34mm.The multicell eggs were round, deep yellow or yellowish orange in colour. The space between the egg wall and the inner developing embryo was visible. The diameter of the egg was 0.41mm.The eye stage eggs were round and orange in colour. The yolk granules were not denser. Segmentation and organogenesis were clearly seen. The eye spots appeared as scarlet crescent. The egg diameter was 0.48mm.The pigment stage eggs were brown in colour with slightly elliptical shape. Appendages of the embryonic larvae were pigmented. The egg diameter was 0.57 mm. The Heart beat stage eggs were dark brown or black in colour. The eyes were round in shape. The heart started to beat vigorously. The diameter of the egg was 0.64 mm.In prehatching stage the rate of heartbeat was increased and the chromatophores were also found increased throughout the body. The diameter of the egg was 0.73mm.