4,426 research outputs found
Prospects of development of marine fisheries resources in Lakshadweep
A good data base has already been developed by CMFRI on various marine resources of Lakshadweep islands and related conservation problems. In the present paper, the potentialities and the areas where future research and developmental activities need to be directed are briefly discussed
Pathway of human AS3MT arsenic methylation
A synthetic gene encoding human As(III) S-adenosylmethionine (SAM) methyltransferase (hAS3MT) was expressed, and the purified enzyme was characterized. The synthetic enzyme is considerably more active than a cDNA-expressed enzyme using endogenous reductants thioredoxin (Trx), thioredoxin reductase (TR), NADPH, and reduced glutathione (GSH). Each of the seven cysteines (the four conserved residues, Cys32, Cys61, Cys156, and Cys206, and nonconserved, Cys72, Cys85, and Cys250) was individually changed to serine. The nonconserved cysteine derivates were still active. None of the individual C32S, C61S, C156S, and C206S derivates were able to methylate As(III). However, the C32S and C61S enzymes retained the ability to methylate MAs(III). These observations suggest that Cys156 and Cys206 play a different role in catalysis than that of Cys32 and Cys61. A homology model built on the structure of a thermophilic orthologue indicates that Cys156 and Cys206 form the As(III) binding site, whereas Cys32 and Cys61 form a disulfide bond. Two observations shed light on the pathway of methylation. First, binding assays using the fluorescence of a single-tryptophan derivative indicate that As(GS)3 binds to the enzyme much faster than inorganic As(III). Second, the major product of the first round of methylation is MAs(III), not MAs(V), and remains enzyme-bound until it is methylated a second time. We propose a new pathway for hAS3MT catalysis that reconciles the hypothesis of Challenger ((1947) Sci. Prog., 35, 396-416) with the pathway proposed by Hayakawa et al. ((2005) Arch. Toxicol., 79, 183-191). The products are the more toxic and more carcinogenic trivalent methylarsenicals, but arsenic undergoes oxidation and reduction as enzyme-bound intermediates
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Fishery of stomatopods - an undervalued and unappreciated fishery resource off Chennai
Stomatopods are a neglected fishery resource
among the crustaceans, though it is a common
bycatch in trawl fishing. They are commercially
exploited in certain countries, but in India, they find
market only as a raw material for preparation of fish
meal and poultry feed. In Japan, Orataria orataria
(de Haan, 1844) and in mediterranean countries,
Squilla mantis (Linnaeus, 1758) form a good fishery
and are relished as human food
Rediscovery of the deep sea shrimp Glyphocrangon investigatoris Wood- Mason and Alcock, 1891 from Indian waters
Details on the deep sea shrimp Glyphocrangon investigatoris
caught off Nagapattinam and landed at Chennai Fisheries
Harbour is reported here. This species was first recorded by the
Investigator expedition from Bay of Bengal and later from Porto
Novo. This is the first record from regular trawl fishery. As the
species is reported here more than a century after its first
description from India, the distinct morphological features is
presented along with the colour photographs of the specimen
Large-sized stomatopod Lysiosquilla tredecimdentata from north Tamil Nadu coast
On 6th June 2006, a large-sized stomatopod measuring 278 mm in total length was obtained from the trawl catches landed at Cuddalore Fisheries Harbour. It was identified as Lysiosquilla tredecimdentata belonging to the family Lysiosquillidae
Observations on the fishery of croakers (Sciaenidae) in the trawling grounds off Rameswaram Island
Croakers (Family : Sciaenidae) form one of the important demersal finfish resources of India. From the region off Rameswaram Island (8o55'-9o20'N & 79┬░-79┬░40'E), the mechanised trawlers land annually about 425t of croakers which form 3-6% of total trawl catch. The present study was taken up in 1988 and provides information on the sciaenid fishery including hydrographical parametersrelated fluctuations during 1988-'92
Fishery, biology and yield estimates of Portunus sanguinolentus off Chennai
The fishery and stock characteristics of the dominant species of
crab, Portunus sanguinolentus was studied along the Chennai
coast. The annual crab landings during the period 1998-2007
ranged from 236 t to 1,628 t with the catch rate fluctuating
between 0.78 kg/h and 2.01 kg/h. The carapace width of P.
sanguinolentus in the fishery was 41-165 mm for females and
41-155 mm for males. Females were dominant throughout the
period of study, the overall sex ratio 1:1.41
Potential of Ornamental marine stomatopods- Tamilnadu Chennai coasts
Certain crustaceans have potential as a sustainable source of ornamental animals. They are a dominant group living on coral reefs. This group is incredible diverse with regard to shape, colour and life style
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