EFFECT OF ENVIRONMENTAL FACTORS ON THE REPRODUCTION OF MARINE CRAB, PORTUNUS SANGUINOLENTUS

Sarode Babita P.

Volume : VIII, Issue : III, March - 2019

EFFECT OF ENVIRONMENTAL FACTORS ON THE REPRODUCTION OF MARINE CRAB, PORTUNUS SANGUINOLENTUS

Sarode Babita P.

Abstract :

India has vast marine as well as freshwater resources having immense potential to be utilized for aquaculture too. Marine resources of India cover sea area along a coastline of 8185 km. In addition there are other related resources comprising backwaters, impoundment, lagoons and estuaries, besides mangroove. In all 1.42 million ha of these water a substantial part of which is beyond coastal regulation zone (CRZ) could be developed for undertaking sustainable and environment friendly coastal aquaculture , similarly inland water in the form of 14 large, 44 medium and many small rivers, 1.2 lakh ha. of irrigation canals, 2.90 million ha. of lakes and reservoirs, 1.30 million ha. of beds and direct water bodies and 2.85 million ha. of ponds and tanks can offer sizeable area for taking up aquaculture activities . Manmade activities such as addition of sewage, suspended solids, and heavy metals affect adversely the ecosystem. These man–made activities, as well as changes in environmental parameters, apart from sources thermal discharge and radioactive substances, affect the balance of ecosystem. Seasonal variations in the environmental factors such as temperature, rainfall and photoperiod affect biotic community and are closely related to species survival. But effluents released by thermal power station in this area affected the productivity of economically important crustaceans Therefore efforts are made to understand the effect of these environmental factors on reproduction of marine crab, Portunus sanguinolentus. Maximum temperature caused quick maturation of gonads. Maximum values of light hours resulted in successful gametogenesis increasing the gonadal indices of female crab. During rainy season, maximum number of ovigerous females were found in the collection