FT Vol.39(2)
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- ItemStandardization of Mesh Size of Gill Nets for the Commercial Exploitation of Kawakawa, Euthynnus affinis (Cantor) in Thoothukkudi Coastal Waters, Southeast coast of India(Society of Fisheries Technologists (India)Cochin, 2002)Euthynnus affinis forms notable fishery in Thoothukkudi coastal waters with peak season from June to September. Euthynnus affinis is captured in small meshed gillnets popularly called 'PODIVALAI' with mesh size ranging from 60 mm to 115 mm. The present study deals with the standardization of mesh size to capture the commercially significant length group (476-600 mm) of E. affinis and its enmeshing pattern in gillnets with three different mesh sizes. The optimum mesh size for the commercial exploitation of £. affinis in Thoothukkudy coastal waters is found to be 104.2 mm. Further, the study recommends to discourage the use of gill net with 50 mm mesh size for the capture of E. affinis as this net captures the juveniles of £. affinis.
- ItemPrimary Productivity of the Brackishwater Impoundments along Nethravathi estuary, Mangalore in Relation to Some Physico-chemical Parameters(Society of Fisheries Technologists (India)Cochin, 2002)Primary productivity of brackishwater impoundments along Nethravathi estuary was studied for one year from Feb. 1998 to Jan. 1999. The primary productivity values varied from 1.78 to 13.47 mgC/m3/h and it exhibited a bimodal pattern of distribution with primary peak in May followed by a secondary peak in September. Lower values were recorded during monsoon season (June-Aug). Chlorophyll-a values observed to range from 2.83 to 9.71 mg/ m3 with higher values recorded during monsoon season and lower values in the month of Dec/Jan. The seasonal trend of phaeopigment exhibited trimodal peak during March, November and July
- ItemPattern of Pigment Migration in Second Cheliped of Macrohrachium rosenhergii with Morphotypic Transformation(Society of Fisheries Technologists (India)Cochin, 2002)Changes in cell shape of chromatophores and subsequent pigment migration on the second cheliped of the three main male morphotypes of Macrohrachium rosenhergii are discussed. Cell enlargement as part of pigment accumulation in chromatophore was found to be maximum in Blue clawed males (1.5 \im), followed by Orange clawed males (1.1 m) and Small males (0.65 (im) in male morphotypes of M. rosenhergii. The concentration of pigments at localized sites facilitated by chromatophoric extension through microtubules gave characteristic orange and blue colour to the cheliped, which could directly or indirectly be modulated by the chromtophoric hormones (CH) or pigment dispersing hormones (PDH).
- ItemL-asparaginase Activity in Growing Conditions of Streptomyces spp. associated with Therapon jarbua and Villorita cyprinoids of Veli Lake, South India(Society of Fisheries Technologists (India)Cochin, 2002)Streptomyces spp. isolated from the gut of fish, Therapon jarbua and shellfish, Villorita cyprinoids exhibited L-asparaginase activity under growing conditions in a liquid broth. Streptomyces AQBTJ 60 (isolate from fish) showed maximum enzyme activity at pH 8.0 whereas Streptomyces AQB VC67 showed it at pH 7.0. They showed optimum enzyme activity and growth at temperature 370C. Carbon sources and amino acids had varying influence based on the constituents in the gut or viscera of the host organisms and heavy metals inhibited activity and growth. Similar trend was noticed with sodium chloride in the estuarine strains.
- ItemImpact of Dietary Protein on Growth, Feed utilization and Body composition of Puntius parrah(Society of Fisheries Technologists (India)Cochin, 2002)The juveniles of Puntius parrah were fed with fishmeal based protein diets at concentrations of 10%, 20%, 30%, 40% and 50% by weight for a period of 120 days in cement cisterns. Protein diet at 50% produced superior growth, maximum food consumption, high conversiorf efficiency and better protein digestibility. Digestive enzyme activity and RNA/ DNA ratio were higher in 50% protein diet fed fish. The total dry matter and protein content of the body showed high values in the fish fed with 50% protein diet. 50% protein diet is found optimum for growth enhancement in Puntius parrah.