Evolution of suitable trawl nets for medium size trawlers - 1: Comparative fishing efficiency between 32 m bulged belly, long wing and four panel trawls

Comparative studies of the efficiency of 32 m bulged belly, long wing and four panel trawls have shown that the bulged belly trawl to be superior to the other nets in catching bottom fishes and column fishes. 40% of the bottom fishes and 48% of the column fishes were caught by the bulged belly trawl. However, for prawn catch, the long wing trawl appears to be better as it landed 52% of the total prawn catch of the three nets. Bulged belly trawl was found to be next only to long wing trawl in this respect.

Investigations on long distance transportation of fish. 4. A comparative study of the performance of expanded polystyrene slabs and multi-layer gunny (jute) fabric as insulants

A comparative study of the insulation efficiencies of expanded polystyrene slabs and multi-layer gunny fabric in long distance transportation of fresh iced fish was made. Used plywood boxes (second hand tea chests) were employed as containers and the experiments conducted between Kakinada and Calcutta. All the three insulants tried, namely, 25.4 mm thick expanded polystyrene slab, four and two layer gunny (jute) fabric, all sealed in 150 gauge polythene sheets, showed comparable insulation efficiencies, considering total bacterial counts, organoleptic qualities and TMA and TVN values of the transported fish as parameters.

Comparative study of three short-chain neurotoxins from the venom of Naja kaouthia (Yunnan, China)

Three short-chain neurotoxins named NT-I, NT-II, and NT-III were purified from the venom of Naja kaouthia, a snake distributed throughout the south of Yunnan province, China, by a series of chromatographic steps, including an FPLC Resource S column. Their molecular weights, determined by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) MS, were 6952.19 Da, 6854.92 Da, and 6828.80 Da, respectively. NT-I consisted of 62 amino acid residues, and the other two consisted of 61 amino acid residues, including 8 cysteines. After hydrolysis by endoproteinase Glu-C, their primary sequences were determined. A test of their activities demonstrated that they effectively inhibited muscle contractions induced by electric stimulation. Furthermore, the extent of inhibition caused by NT-II and NT-III was less than that of NT-I. The IC(50)s were 0.04 mug/ml, 0.20 mug/ml, and 0.23 mug/ml for NT-I, NT-II, and NT-III, respectively. Compared with NT-II and NT-III, the higher activity of NT-I may be a result of the amino acid residue substitution Ile36 to Arg36.

Comparative study of traditional and improved containers for transportation of fresh fish

Traditional bamboo basket and expanded polystyrene insulated plywood box (second hand tea-chest) were compared for transportation of iced marine, fresh water and brackish water fishes from Kakinada to Madras by rail. Quality of fish at dispatching and receiving centres was assessed by organoleptic, total volatile nitrogen (TVN) and total bacterial count (TBC) tests. Based on the results obtained and the prices fetched, the traditional bamboo basket apart from being cheaper was found to be as good as expanded polystyrene insulated plywood box for short distance transportation of iced fish involving less than 24 hours journey.

A note on the comparative catch efficiency of nylon over cotton gill nets in reservoir fishing

The authors conducted a series of experiments to evaluate the relative efficiency of nylon over cotton in tropical waters, particularly in reservoir fishing. The experiments were conducted in the Gobindsagar reservoir (Himachal Pradesh/Punjab). The nets made with both materials were identical in essential details like twine size, mesh size, number of floats arid sinkers and hanging coefficients.

On the comparative fishing experiments with a four-seam and a two-seam trawls on the east coast

Fishing experiments were undertaken to study the relative utility of a newly designed four seam type net on a conventional two seam net at the centre along the East Coast in both inshore and deeper zones (up to 100m.) and the results indicated that the new four seam net has given higher catch rate of 6 to 8% more with higher catch rate of fish supposed to belong to off bottom region. Further this gear found more selective in obtaining Lactarius, which is one of the good variety of fish from trawlers, in both quantity as well as in quality. In terms of horizontal spread this new net gave less on comparison with the conventional two seam net, thereby showed corresponding increase in vertical spread; but warp tension remained more or less same in both the gear. Both gear have worked equally well in majority of depth ranges experimented with optimum spread. Finally the results indicated that the new net can work well from the present trawlers along the coast.

Utilization of treated wood, steel, fibreglass, ferrocement and aluminium in the construction of modern fishing boats and their comparative cost analysis

Modern fishing boats have to be built not only on perfect lines but also with sound and strong construction materials that will ensure a long lasting trouble free service commensurate with the heavy capital investment involved. Choice of construction materials for fishing boats need careful scrutiny as they have to perform too well under most aggressive environments-sea-water and marine atmosphere. A number of alternative boat-building materials are now available whose comparative merits and demerits as well as comparative costs are brought out in this paper.

Technological aspects of preservation and processing of edible shell fishes IV. Comparative efficiency of different glazes in the preservation of frozen crab meat

The present work was undertaken to enlighten upon the comparative efficiency of different glazes in improving the quality of frozen crab meat (Scylla Serrata).

On the comparative efficiency of trawls made of cotton, polyethylene and combination of both the materials

The merits and demerits of cotton, polyethylene and combination of the two materials ascertained on the basis of cost, wear and tear, maintenance, total catch and qualitative analysis of the catch are discussed by making comparative fishing experiments with the three trawl gears made of these materials. The study can be concluded with a suggestion for switching over to polyethylene twisted monofilaments for better, in case of bottom trawls without in any way adversely affecting the catch of shrimps and at the same time for enhanced fish catch. Even though the combination net is found to be equal in efficiency as the polyethylene net this idea cannot be conveniently adopted from the point of view of economy.

Comparative efficiency of frame nets and trammel nets

Fishing experiments were conducted simultaneously with frame nets and trammel nets in the Hirakud Reservoir and the results indicated the relative superiority of frame nets, whose catch rate was two times more than that of the trammel nets.