Exploitation of the brown mussel Perna indica (Kuriakose and Nair) from selected centres along The west coast of Tamil Nadu

The brown mussel, Pema vndica. Is found abundantly on intertldal and subtidal rocks along This study was undertaken to determine the current level of exploitation from selected centres along the west coast of Tamil Nadu, since estimates of catch and effort form part of the basic information required for fishery management

Mechanisation of traditional crafts with outboard motors at Vizhinjam

The present study has been carried out to assess the impact of mechanisation of traditional crafts with outboard motor and its prospects with special reference to Vizhinjam to modernize the traditional fishery

The Sasa-Satsuma higher order nonlinear Schrodinger equation and its bilinearization and multi-soliton solutions

Higher order and multicomponent generalizations of the nonlinear Schrodinger equation are important in various applications, e.g., in optics. One of these equations, the integrable Sasa-Satsuma equation, has particularly interesting soliton solutions. Unfortunately the construction of multi-soliton solutions to this equation presents difficulties due to its complicated bilinearization. We discuss briefly some previous attempts and then give the correct bilinearization based on the interpretation of the Sasa-Satsuma equation as a reduction of the three-component Kadomtsev-Petvishvili hierarchy. In the process we also get bilinearizations and multi-soliton formulae for a two component generalization of the Sasa-Satsuma equation (the Yajima-Oikawa-Tasgal-Potasek model), and for a (2+1)-dimensional generalization.Comment: 13 pages in RevTex, added reference

शूली महा चिंगटों के प्रजनन और स्फूटनशाला प्रौद्योगिकी के विकास में नई प्रगतियाँ

कृपया पूरा लेखा पढ

Lobsters

Among marine crustaceans, lobsters are the most highly priced ones and of significant commercial interest in many countries. Due to their increasing demand as a favourite of epicurean gourmets, lobsters have captured excellent markets in developed countries. Lobster fishing, therefore, is practised on intensive scale throughout the world and a stage has com e that most of the traditional lobster stocks are under heavy exploitation now. According to World Fishery Statistics, the annual lobster production of the world during 1981 - 1990 period ranged from 1.8 lakh tonnes in 1982 to 2.3 lakh tonnes in 1989, thereby showing an increase of only 28% over the years. The average annual production of about 2.1 lakh tonnes of lobsters, which included 1.9 lakh tonnes of spiny lobsters and allied species (92%) and 0.2 lakh tonnes of squat lobsters (8 %), form ed 6 % of the world crustacean landings from the marine sector. The contribution of the form er group from Indian Ocean region for the same period was about 60,000 tonnes on an average of which over 70% was recorded in the Western Indian Ocean mainly from the coasts of South Africa, Om an and Republic of Yemen. India landed an average of about 24,000 tonnes, of which nearly 90% came from the west coast

Mouthpart morphology of phyllosoma of the tropical spiny lobster Panulirus homarus (Linnaeus, 1758)

Mouthpart morphology of Panulirus homarus phyllosoma larva was studied under scanning electron microscope in order to analyse the developmental changes during growth. Phyllosoma larvae have six pairs of mouthparts (mandibles, maxillule, maxilla, maxillipeds I, II, and III), labrum, and paired paragnaths. Increased length of second and third maxillipeds in late stage phyllosoma resulted in the increase of oral field, thus increasing its ability to catch prey. Labrum and paired paragnaths form a semienclosed oral chamber where mastication by the mandibles occurs. The improved threshing and tearing efficiency in late instars (stage VI-VIII) is facilitated by morphological changes in the mouthparts viz., increase in oral field, increased robustness and number of spinose setations of maxillule, and lengthy maxillipeds, indicating that the late instar larvae can process fleshier prey as compared to the early instar counterparts

On an unusual catch of bigeye tuna Selar crumenophthalmus (Bloch) in shore seine at Vizhinjam

The article describes an unusual catch the carangid Selar crumenophthalmus (Bloch) was obtained close to the shore at Vizhinjam on 3rd December, 1985, using shore seine. The total catch was estimated to be around 33.4 tonnes caught by 10 units. The catch was exclusively of the single species of carangid Selar crumenophthalmus (Bloch) and s forms a fishery at Vizhinjam during August to March with a peak period from November to March

Marine Fish Calendar 9. Vizhinjam

Vizhinjam, an important fish landing centre in the fishery zone extending from Kollangode in the south to Valiaveli in the north spreading over a distance of 50 km on the southwest coast of India. Data collected over a period of five years, from 1981 to 1985, from the landing centre at Vizhinjam have been analysed to draw up a general fishery calendar suitable for this centre elucidating the cyclic changes in the abundance and dominance of the commercially important species/ groups of fish within a year. The data show that the annual marine fish landings (fin fish alone) at Vizhinjam ranged from 5,207.01 t in 1981 to 9,726.2 t in 1985 with the annual average landings at 6,374.41 t

Thin films of perfectly polar crystallites with uniaxial orientational ordering

The family of metal-organic complexes,(4-dialkylaminopyridyl)bis(acetylacetonato)zinc(II) which show perfectly polar assembly in the crystalline state are found to grow as orientationally ordered crystallites in vapor deposited thin films on glass substrates. A unique crystallographic axis of the crystallites, the longest unit cell axis in most cases, is oriented perpendicular to the substrate plane. The fact that the current observations cover a family of compounds is novel and of general significance for oriented thin film growth on amorphous substrates. Crystal structure, thin film morphology and second harmonic generation of a representative system are presented; the crystallites in the thin films do not show azimuthal orientational ordering