Studies On Pobtunid Crabs [Crustacea Decapoda Brachyura)

True crabs are the most fascinating group of organisms among the decapod crustaceans. Great importance is attached at present to the increased exploitation of these animals and therefore there is great scope for further development of their fishery. They have a broad and hard carapace, massive chelate legs, bent abdomen and exhibit high degree of adaptation to the environment. They show pelagic, benthic, intertidal, burrowing and terrestrial modes of life. Their commensal association with other invertebrates, their breeding behaviour and life history are of great interest to biologists. More than six hundred species of crabs are known to occur in Indian waters and among them about eight species form a regular fishery along the entire stretch of peninsular India (Rao §§_al., 1973) round the year. Crab fishery in India is fast developing and there is vast scope for them as there are many more potential species. Among the various crustacean diets, crabs are celebrated for deliciousness and for nutritional richness. In recent days, crab food items have become more popular and gained global reception. These resources can also be augmented further by culturing them in ponds in the future. Information on biology and ecology of constituent species go a long way not only in effective exploitation and regulation of the respective fishery resources but also helps in evolving a suitable gear for their capture. Information collected on the national level in various aspects as reproduction, growth rate, larval development, parasites, diseases, nutritive values etc. will be of help in evolving a national policy for the effective utilisation and conservation of this resource. They also provide the baseline information for undertaking any purposeful and meaningful culture activities. Information on the various aspects mentioned above is very much restricted in true crabs and hence the present study

Heterotrophic bacteria from the continental slope sediments of arabian sea

The marine environment is indubitably the largest contiguous habitat on Earth. Because of its vast volume and area, the influence of the world ocean on global climate is profound and plays an important role in human welfare and destiny. The marine environment encompasses several habitats, from the sea surface layer down through the bulk water column, which extends >10,000 meters depth, and further down to the habitats on and under the sea floor. Compared to surface habitats, which have relatively high kinetic energy, deep-ocean circulation is very sluggish. By comparison, life in the deep sea is characterized by a relatively constant physical and chemical environment. Deep water occupying the world ocean basin is a potential natural resource based on its properties such as low temperature, high pressure and relatively unexplored properties. So, a judicious assessment of the marine resources and its management are essential to ensure sustainable development of the country’s ocean resources. Marine sediments are complex environments that are affected by both physiological and biological factors, water movements and burrowing animals. They encompass a large extent of aggregates falling from the surface waters. In aquatic ecosystems, the flux of organic matter to the bottom sediments depend on primary productivity at the ocean surface and water depth. Over 50% of the earth’s surface is covered by deep-sea sediments that are primarily formed through the continual deposition of particles from the productive pelagic waters (Vetriani et al., 1999). These aggregates are regarded as ‘hot spots’ of microbial activity in the ocean (Simon et al., 2002). This represents a good nutritional substrate for heterotrophic bacteria and favours bacterial growth