मत्स्य खाधों की सुरक्षा केलिए व्यवस्था

कृपया पूरा लेख पढे

Life Cycle and Biology of Portunid Crabs

In crustaceans, as growth progresses, certain dimensions of the animal’s body may grow much more than others, resulting in the phenomenon known as relative growth (Hartnoll, 1974). Studies of relative growth are often used to determine changes in the form and size of the abdomen, pleopods, or chelipeds during ontogeny. Knowledge of these distinguishing characters and size relationships in sexually mature individuals is of particular importance in the study of commercially valuable crustaceans. Such knowledge can be useful for further studies on the life history of the species and in the development of its fishery, resource management, and culture. The mathematical length-weight relationship thus yields information on the general well-being of individuals, variation in growth according to sex, size at first maturity, gonadal development, and breeding season

Blue Swimmer Crab Portunus pelagicus (Linnaeus, 1758)

Blue swimmer crab is one of the most important marine crab in India, distributed all along the east and west coasts with a dominant fishery at Palk Bay and Gulf of Mannar. Suitable species for marine farming. Males grow to a maximum size of 650 g and females 550 g

Crabs and Crab Fishery of the Mandapam Area

In our country, crab fishery is mainly contributed by portunid crabs those which belong to three generae ie., Scylla. Portunus and Charybdis. They have the typical portunid shape with carapace having 4-9 anterolateral teeth. Chelepeds are longer than all legs and last pair typically paddle shaped

Classification, Biodiversity and Conservation of Marine Commercial Crabs of India

One of the best known and most intensely studied groups is the true crabs of the infraorder Brachyura. Brachyuran crabs belong to the Order Decapoda, the most diverse group of crustaceans alive today (Ng et al., 2008). The known size of crabs now ranges from a maximum leg span of approximately 4 m in the giant Japanese spider crab Macrocheira kaempferi and a maximum carapace width of 46 cm in the giant Tasmanian crab Pseudocarcinus gigas to a minimum of 1.5 mm across the carapace for a mature ovigerous female pinnotherid, Nannotheres moorei, the smallest known species of crab. Every living thing is classified into one of the three domains

स्फुटनशाला में पोर्टुनिड केकडे 'थ्री स्पोट केकडा ' पोर्टूनस संगीनोलेन्टस के ब्रूडस्टॉक विकास और पुनरुत्पादन प्रदर्शनी

स्फुटनशाला में पोर्टुनिड केकडे 'थ्री स्पोट केकडा ' पोर्टूनस संगीनोलेन्टस के ब्रूडस्टॉक विकास और पुनरुत्पादन प्रदर्शन

Indian Crustacean Resources: Distribution, Commercial Exploitation, Utilization and Trade

The crustacean fisheries of India have considerable importance in the economy of the country, earning very valuable foreign exchange. Edible marine crustaceans consisting of prawns, lobsters and crabs form the most important constituents of the commercial fish landings of India. In 2009 the total marine crustacean landings were 493356 tonnes of which 83 per cent was constituted by prawns (penaeid and non-penaeid). This chapter discusses the important commercial species of prawns, lobsters and crabs of Indian coast

Book Review: Freshwater prawn culture: the farming of Macrobrachium rosenbergii” by New & Valenti

This is an upgrade of the book “Freshwater prawn culture: the farming of Macrobrachium rosenbergii” by New & Valenti (2000; 428 pp.). The new book is edited by a group of five as documented in the title: New, Valenti, Tidwell, D’Abramo & Kutty. The contents have been contributed by “a team of 44 exceptionally well known and internationally-respected authors” originating from no less than 11 countries across the globe. This new edition is more voluminous than the 2000 version and has 24 chapters, each giving a vivid picture of the specific subject discussed, with an index concluding the book

Food and feeding of the blue swimmer crab, Portunus pelagicus (Linnaeus, 1758) (Decapoda, brachyura) along the Coast of Mandapam, Tamil Nadu, India

Food habits of the blue swimmer crab, Portunus pelagicus were investigated using specimens collected from trawl catches in the Mandapam region, Tamil Nadu, along the east coast of India (9◦20-25_N 79 ◦ 5-10_E), during the period January to December, 1999. The stomach contents of 452 crabs, ranging from 61 to 180 mm carapace width, were analysed. Their diet included crustaceans, molluscs, fishes, unidentifiable matter, and debris. In adult crabs, crustaceans constituted the dominant food source and these were present in 78.43% of the stomachs analysed. The stomach contents of juveniles and sub-adults were dominated by debris. There was no significant difference between sexes in the frequency of occurrence of food items or in their “percentage points” [= the (virtual) percentual contribution to the fullness of a 100% full stomach]. However, there was a difference between the stomachs of ovigerous and non-ovigerous females. There were also significant differences in the preference for food items in the different size groups of the crab. The results collected from the present study showed that P. pelagicus exhibits, in this region at least, a clear preference for crustaceans