193 research outputs found

    Taxonomy, Biology and Distribution of Deep Sea Shrimps

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    Shellfish systematics is the most unique one in fisheries science in view of its importance and implications in diversity. The systematic zoology is the science that discovers names, determines relationships, classifies and studies the evolution of living organisms. It is an important branch in biology and is considered to be one of the major subdivisions of biology having a broader base than genetics, biochemistry and physiology. The shellfish includes two highly diversified phyla i.e. phylum Arthropoda and phylum Mollusca. These two groups are named as shellfishes because of the presence of exoskeleton made of chitin in arthropods and shells made of calcium in molluscs. These two major phyla are invertebrates. They show enormous diversity in their morphology, in the habitats they occupy and in their biology. Phylum Arthropoda includes economically important groups such as lobsters, shrimps, crabs. Taxonomical study reveals numerous interesting phenomena in shellfish phylogeny and the study is most indispensable for the correct identification of candidate species for conservation and management of our fishery resources and aquaculture practices. On the whole taxonomic study on shellfishes furnishes the urgently needed information about species and it cultivates a way of thinking and approaching of all biological problems, which are much needed for the balance and well being of shellfish biology as a whole

    Taxonomy, Biology and Distribution of Lobsters

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    Lobsters are among the most prized of fisheries resources and of significant commercial interest in many countries. Because of their high value and esteemed culinary worth, much attention has been paid to lobsters in biological, fisheries, and systematic literature. They have a great demand in the domestic market as a delicacy and is a foreign exchange earner for the country

    Taxonomy, Biology and Distribution of Deep Sea Shrimps and Lobsters

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    Shellfish systematics is the most unique one in Fisheries Science in view of its importance and implications in diversity. The systematic zoology is the science that discovers names, determines relationships, classifies and studies the evolution of living organisms. It is an important branch in biology and is considered to be one of the major subdivisions of biology having a broader base than genetics, biochemistry and physiology. The shellfish includes two highly diversified phyla i.e. phylum Arthropoda and phylum Mollusca. These two groups are named as shellfishes because of the presence of exoskeleton made of chitin in arthropods and shells made of calcium in molluscs. These two major phyla are invertebrates. They show enormous diversity in their morphology, in the habitats they occupy and in their biology. Phylum Arthropoda includes economically important groups such as lobsters, shrimps, and crabs. Taxonomical study reveals numerous interesting phenomena in shellfish phylogeny and the study is most indispensable for the correct identification of candidate species for conservation and management of our fishery resources and aquaculture practices. On the whole taxonomic study on shellfishes furnishes the urgently needed information about species and it cultivates a way of thinking and approaching of all biological problems, which are much needed for the balance and well being of shellfish biology as a whole

    Isolation and characterization of antagonistic Streptomyces spp. from marine sediments along the southwest coast of India

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    Antagonistic Streptomyces spp. were isolated from marine and mangrove sediment samples collected off Cochin, along the southwest coast of India. Sediment samples were pre-treated and following the soil dilution technique, samples were surface plated on starch casein agar and actinomycetes isolation agar. In the primary screening, 7.4% of presumptive actinomycetes (135 isolates) showed antibacterial activity against one or more bacterial fish pathogens and 3.7% of these cultures showed broad spectrum activity against the tested pathogens. Morphologically white powdery colonies with chalky white /grey appearance were selected as presumptive Streptomyces cultures. Isolates subjected to biochemical, physiological and 16S rDNA characters revealed the presence of three species of Streptomyces dominated by Streptomyces tanashiensis followed by S. viridobrunneus and S. bacillaris. Isolates characterized by 16S rDNA indicated the presence of 650 bp band in Streptomyces spp. Primary screening for activity against selected fish pathogens was done by a cross streak method using modified nutrient agar medium. Prominent isolates showing high zone of activity against the fish pathogens ranged 17-35 mm by the paper disc method. Enriched broth of selected isolates showing high antagonistic activity was screened for pharmacologically active agents revealed ethyl acetate fractions to be active against selected microbial pathogens

    Incidence and Molecular Typing of Vibrio parahaemolyticus from Tiger Shrimp Culture Environments along the Southwest Coast of India

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    Vibrio parahaemolyticus is one of the most prevalent food-borne pathogens along the southwest coast of India, where marine foods are frequently consumed. Shrimp (Penaeus monodon) and environmental samples were collected from aquaculture farms located in and around Cochin. Confirmation of the biochemically identified strains with species-specific toxR gene and detection of virulent genes viz., tdh and trh was performed by polymerase chain reaction (PCR). The phenotypic markers for the presence of tdh and trh genes were assayed by Kanagawa phenomenon and urease activity, respectively. Protease activity was examined to identify other potential virulence factors. After phenotypic characterization of bacterial strains fingerprinting of genomic DNA was carried by various typing methods, viz., random amplified polymorphic DNA (RAPD), enterobacterial repetitive intergenic consensus sequence (ERIC), repetitive extragenic palindromic sequence (REP), and ribosomal gene spacer sequence (RS) PCR methods to assess the genetic diversity within the isolates. Eighteen percent of the samples were found positive for the incidence of V. parahaemolyticus by biochemical protocols and toxR (368 bp) targeted PCR. PCR analyses revealed 1% of the samples positive for tdh (269 bp) and trh (500 bp) gene. RAPD analysis revealed clustering of toxigenic strains into a single group. Cluster analysis revealed the conglomeration of isolates into two, five, and seven major groups using RS, ERIC, and REP PCR methods, respectively. RS PCR generated fewer amplified bands compared to REP and ERIC PCR methods, thus giving scope for higher discrimination. Moreover, RS PCR patterns were more discernible visually from other patterns, suggesting RS PCR as a considerably practical method for routine use

    Occurrence and distribution of virulent strains of Vibrio parahaemolyticus in seafoods marketed from Cochin (India)

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    This study was aimed for the detection of Vibrio parahaemolyticus by biochemical and molecular methods in seafood samples collected from the markets of Cochin located at the southwest coast of India.Atotal of seventy-two V. parahaemolyticus cultures were isolated by selecting sucrose and cellobiose non-fermenting colonies. All the biochemically confirmed strains were found to have 368-bp toxR gene fragment, while an additional 24% of the samples were confirmed as V. parahaemolyticus by toxR based polymerase chain reaction (PCR) from enrichment broths

    Note on a fishery of Parapenaeus longipes along the Veraval Coast

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    Parapenaeus longipes, commonly known as “Flamingo shrimp” and locally as “Bhoonsi”,it is not known to occur exclusively as fishery in any area of India and abroad

    Preparation of eicosapentaenoic acid concentrates from sardine oil by Bacillus circulans lipase

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    An extracellular lipase extracted from Bacillus circulans, isolated from marine macro alga, Turbinaria conoides, was used to prepre n-3 polyunsaturated fatty acid(PUFA) concentrates from sardine oil trygliceride

    Guaiane sesquiterpenes from seaweed Ulva fasciata Delile and their antibacterial properties

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    Two new guaiane sesquiterpene derivatives, guai-2-en-10a-ol (1) and guai-2-en-10a-methanol (2), were chromatographically purified as major constituents of the CHCl3/CH3OH (1:1, v/v) soluble fraction of Ulva fasciata. Acetylation of 2 furnished guai-2-en-10a-methyl methanoate (3) with acetyl group at C11 position. The structures of the compounds were elucidated using one and two-dimensional NMR and mass spectrometric analysis. Compounds 2 and 3 exhibited significant inhibition to the growth of Vibrio parahaemolyticus with minimum inhibitory concentrations of 25 and 35 mg/mL, respectively. The electronegative C10 acetyl group with high polarisability (7.02� 10�24 cm3) in 3 appeared to withdraw electron cloud from substituted cycloheptyl ring and (R)-3-methylcyclohept-1-ene moiety, thus acting as the nucleophilic center of the molecule resulting in high bioactivity

    Lobster and Deep Sea Shrimp Resources and Biology In: ICAR Sponsored Winter School on Recent Advances in Fishery Biology Techniques for Biodiversity Evaluation and Conservation, 1-21 December 2018, Kochi.

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    Shellfish systematics is the most unique one in Fisheries Science in view of its importance and implications in diversity. The systematic zoology is the science that discovers names, determines relationships, classifies and studies the evolution of living organisms. It is an important branch in biology and is considered to be one of the major subdivisions of biology having a broader base than genetics, biochemistry and physiology. The shellfish includes two highly diversified phyla i.e. phylum Arthropoda and phylum Mollusca. These two groups are named as shellfishes because of the presence of exoskeleton made of chitin in arthropods and shells made of calcium in molluscs. These two major phyla are invertebrates. They show enormous diversity in their morphology, in the habitats they occupy and in their biology. Phylum Arthropoda includes economically important groups such as lobsters, shrimps, crabs. Taxonomical study reveals numerous interesting phenomena in shellfish phylogeny and the study is most indispensable for the correct identification of candidate species for conservation and management of our fishery resources and aquaculture practices. On the whole taxonomic study on shellfishes furnishes the urgently needed information about species and it cultivates a way of thinking and approaching of all biological problems, which are much needed for the balance and well being of shellfish biology as a whole
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