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

दायित्वपूर्ण चिंगट पालन के लिए बेहत्तर प्रबंधन उपाय

कृपया पूरा लेख पढे

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

चेन्नई की समुद्री क्रस्टेशियाई संपदा

कृपया पूरा लेखा पढ

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

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

Trawl fisheries of penaeid shrimps and crabs off Chennai coast - An assessment before and after Tsunami

The December 2004 tsunami played a havoc on the marine fishing communities and fishing infrastructure facilities along the Tamil Nadu coast in general and Chennai, Cuddalore and Nagapatinam coasts in particular, which had resulted in the total absence of mechanized and non-mechanized fishing from the last week of December 2004 to the third week of March 2005.An attempt has been made here to compare the trawl fisheries for penaeid shrimps and crabs during November-December 2004 and March- June 2005 with that of November 2003 to June 2004