Larval biology of the spiny lobsters of the genus panulirus

Lobsters are renowned the world over as tasty delicacies and are in great demand for Epicurian gourests. As a result these animals found in different parts of the world from countries like India they are mostly frozen and exported thus earning considerable foreign exchange for the country. Importance of this crustacean is thus well known and whatever harvested from nature are utilized to the maximum extent. The demand being much more than what is being produced the need for artificial culture becomes evident. In this context a complete knowledge of the lifecycle ,larval biology and their culture is very essential. Thus with the object of studying the life history of the commercially important lobsters fished from Indian waters the larval biology of panulirus homarus has been taken up as the project for the present study

Genetic divergence in lobsters (Crustacea: Palinuridae and Scyllaridae) from the Indian EEZ

The management of exploited species requires the identification of demographically isolated populations that can be considered as independent management units (MUs), failuring in which can lead to over -fishing and depletion of less productive stocks. By characterizing the distribution of genetic variation, population sub structuring can be detected and the degree of connectivity among populations can be estimated. The genetic variation can be observed using identified molecular markers of both nuclear and mitochondrial origin. Hence, the present work was undertaken to study the genetic diversity and population/stock structure in P. homarus homarus and T. unimaculatus from different landing centres along the Indian coast using nuclear (RAPD) and mitochondrial DNA marker tools which will help towards developing management strategies for management and conservation of these declining resources.To make consistent conservation and fisheries management decisions, accurate species identifications are needed. It is also suggested that it is not always desirable to rely on a single sequence for taxonomic identification. Thus, the feasibility of using partial sequences of additional mitochondrial genes like 16SrRNA, 12SrRNA and nuclear 18SrRNA has also been explored in our study. Phylogenies provide a sound foundation for establishing taxonomy. The present work also attempts to reconstruct the phylogeny of eleven species of commercially important lobsters from the Indian EEZ using molecular markers

Standardization of Optimum Conditions for the Production of Glucosamine Hydrochiloride from Chitin

The study entitled standardization of optimum conditions for the production of glucosamine hydrochloride from chitin. Shellfish processing industries around the world turn out a significant quantity of head and shell as industrial waste. The waste must be removed immediately to prevent the contamination to the processing environment. The technique that are available for their disposal include ocean dumping, incineration or disposal of landfill sites. In this thesis the techniques and methods are used to process glucosamine hydrochloride from crustacean processing waste. Chitin is a nitrogenous polysaccharide, which is white, hard, inelastic, found in outer skeleton of insects, crabs, shrimp and lobsters and in the internal structures of other invertebrates. Glucosamine can be considered as a nutraceutical product by virtue of its properties. It is important for healthy skin, and plays a major role in the healing of surgical incisions and skin wounds. Deproteinisation of shrimp shell had significant effect on quality of chitin. Demineralization is also influences chitin quality. Solvents used for glucosamine hydrochloride affects the final yield and purity.

Biology, population characteristics and fishery of the speckled shrimp Metapenaeus monoceros (Fabricius, 1798) along the Kerala coast

Crustaceans comprising numerous edible species of prawns, lobsters and crabs inhabiting different ecosystem form significant portion of the aquatic food resources of the world. Among the crustaceans, prawns are the most commercially exploited group and hold premier rank by virtue of their importance as an esteemed food of gourmet and on account of their high export value. Met-ape-naeus manoceras (Fabricius, 1798) which is known IS,Speckled shrimp’ (FAD name) and ‘Brown shrimp’ ( common nameused in the industry) is one of the commercially important marine penaeid prawns of India. During 1995, M. monaceros catch constituted 7.5 Z of the all India marine penaeid prawn landings. M. monoceros attains a maximum length of about 200 mm and has high export potential.Thus realising the growing importance of M. monoceros in the capture fisheries, it was felt, that it would be ideal to carry out detailed study on this species for rational exploitation and management of its fishery. Hence, the present work entitled, “Biology, population characteristics and fishery of the speckled shrimp Hetapenaeus monoceros (Fabricius, 1798) along Kerala coast“ was undertaken by the author. The thesis is laid out in seven chapters comprising TAXONOMY, FOOD AND FEEDING HABITS, AGE AND GROWTH, REPRODUCTION,LENGTH-WEIGHT RELATIONSHIP, FISHERY and POPULATION DYNAMICS

Biochemical Genetics Of Selected Commercially Important Penaeid Prawns

‘Biochemical genetics of selected commercially important penaeid prawns‘ dloted was carried out by collecting samples from different important fishing ceatres of India and the practical work was carried out in the Research Centre of CMFRI laboratories attached with those places. On the whole, in crustacea little importance has been given so far in finding out tin genetic characteristics of different species, genetic variation within and between species and ontogenetic variations in lobsters, prawns and other crustaceans. Prawn is caunercially important group where very little attention had been given so far to find out the racial divergence which may exist in cufferent species. with the increased foreign exchange earning and consequent indiscriminate over exploitation of existing resources of prawns resulting in depletion of the marine rescurces, alternative ways and augmenting production has become essential. In this connection genetic manipulation of the broodstock will surely bring about the heterogenous characters to multiply production. In order to understand racial fragmentation of sane of the coumercially important prawns such as Pengeus ggdicus and Parggenagsis sgliferg the isozyme studies were carried out. Qatogenetic variation of g. indicus showed stage specific electrophoretic variation. Inter species variation studies was carried out for the closely aligned Penaeus species

Studies On Spiny Lobster Fishery Of South West Coast Of India

A study on the different aspects of spiny lobster fishery of south west coast of India with respect to the factors relevant to production, including conservation and management measures for putting this fishery on sound basis needs no emphasis. There are some aspects of this fishery which have not been sufficiently inquired into and some others which have been touched upon intermittantly and in a languid way. The attempt here is to throw light on these aspects from a production point of view. Emphasis is on harvest technology and the conservation and management measures and it is proposed to make a critical review of such measures in vogue in other lobster fishing countries and discuss about suitable methods for this fishery

Energetics 0f A Few Marine Crustaceans

Success achieved in seed production and culture of prawns induced researchers to explore the feasibiltiy of culture of other important crustaceans like lobsters and crabs. The CMFRI initiated a project to study the prospects of spiny lobster’ culture and I was associated with this project from the beginning. Compared to shrimp farming, culture of spiny lobsters is an entirely different proposition due to inherent problems in producing their seeds. The emphasis on .obster culture, therefore, shifted to rearing of juvenile lobsters, which form a major portion in commercial lobster landings in India. Commendable success was achieved in enhancing growth rate of four important speices of spiny lobsters by bilateral eyestalk ablation. But due to strong reservations expressed against the "blinding" of lobsters by people from all walks of life, this technique could not be tested commercially for its economic viability. As in prawns, energetics of reproduction and egg development have not yet been documented in spiny lobsters and so these aspects were included in this study. Though some limited informations on food conversion efficiency are availble in spiny lobster, a detailed study on the effect of size and sexual maturity on food conversion was wanting and this also was included in this investigation. The most dominant spiny lobster in south east and south west coast of India, Panulirus homarus (Linnaeus) was selected for this study. Uptake, accumulation and utilization of minerals and trace elements are important events during embryogenesis of aquatic invertebrates. The scope of this study was widened to include these aspects also in order to understand how specific requirements of minerals and trace elements are met in the developing eggs of these two species of crustaceans.

Brachyuran Crabs of Cochin Backwaters- Diversity, Habitat Ecology and Systematics, with special emphasis to Genus Scylla

Among the decapod crustaceans, brachyuran crabs or the true crabs occupy a very significant position due to their ecological and economic value. Crabs support a sustenance fishery in India, even though their present status is not comparable to that of shrimps and lobsters. They are of great demand in the domestic market as well as in the foreign markets. In addition to this, brachyuran crabs are of great ecological importance. They form the conspicuous members of the mangrove ecosystems and play a significant role in detritus formation, nutrient recycling and dynamics of the ecosystem. Considering all these factors, crabs are often considered to be the keystone species of the mangrove ecosystem. Though several works have been undertaken on brachyuran crabs world –wide as well as within the country, reports on the brachyuran crabs of Kerala waters are very scanty. Most of the studies done on brachyuran fauna were from the east coast of India and a very few works from the west coast. Among the edible crabs, mud crabs belonging to genus Scylla forms the most important due to their large size and taste. They are being exported on a large scale to the foreign markets like Singapore, Malaysia and Hong Kong. Kerala is the biggest supplier of live mud crabs and Chennai is the major centre of live mud crab export. However, there exists considerable confusion regarding the identification of mud crabs because of the subtle morphological differences between the species.In this context, an extensive study was undertaken on the brachyuran fauna of Cochin Backwaters, Kerala, India, to have a basic knowledge on their diversity, habitat preference and systematics. The study provides an attempt to resolve the confusion pertaining in the species identification of mud crabs belonging to Genus Scylla. Diversity study revealed the occurrence of 23 species of brachyuran crabs belonging to 16 genera and 8 families in the study area Cochin Backwaters. Among the families, the highest number of species was recorded from Family Portunidae .Among the 23 crab species enlisted from the Cochin backwaters, 5 species are of commercial importance and contribute a major share to the crustacean fishery of the Cochin region. It was observed that, the Cochin backwaters are invaded by certain marine migrant species during the Post monsoon and Pre monsoon periods and they are found to disappear with the onset of monsoon. The study reports the occurrence of the ‘herring bow crab’ Varuna litterata in the Cochin backwaters for the first time. Ecological studies showed that the substratum characteristics influence the occurrence, distribution and abundance of crabs in the sampling stations rather than water quality parameters. The variables which affected the crab distribution the most were Salinity, moisture content in the sediment, organic carbon and the sediment texture. Besides the water and sediment quality parameters, the most important factor influencing the distribution of crabs is the presence of mangroves. The study also revealed that most of the crabs encountered from the study area preferred a muddy substratum, with high organic carbon content and high moisture content. In the present study, an identification key is presented for the brachyuran crabs occurring along the study area the Cochin backwaters and the associated mangrove patches, taking into account the morphological characters coupled with the structure of third maxillipeds, first pleopods of males and the shape of male abdomen. Morphological examination indicated the existence of a morphotype which is comparable with the morphological features of S. tranquebarica, the morphometric study and the molecular analyses confirmed the non existence of S. tranquebarica in the Cochin backwaters.