Guidelines for identification of postlarvae

From the morphological resemblances and the progress of changes in morphology accompanying growth, it is possible t o trace tho development of fishes. However, the easiest means in identifying fish larvae is t o identify the largest stage and work down to the smallest

Guidelines for the identification of larvae

The different stages or phases in the life history of fishes markedly vary from the adult and the degrees of difference vary in different groups. However, there is no sudden metamorphosis in fishes and the change of form is slow. The differences between the larvae and adults of some fishes have led erroneously to the descriptions of the early stages of eel as Leptocephalus, Molidae as Molacanthus and Centaurus. Chaetodontidae as Tholichthys, Schindleria as Heiinirhamphus and Lampreys as Ammocoetus, Later, these generic names were given the status of stages in the early life history of the fish concerned

Our fisheries resources and the role of upwelling in their fluctuations Part II: Primary productivity and fisheries potential

The availability of essential nutrients in the productive upper layers is one of the important factors governing the magnitude of organic production. The nutrients are brought up into the euphotic zone by the vertical mixing of the water caused by wind and wave action; processes associated with ocean currents and by upwelling of deep water

Our fisheries resources and the role of upwelling in their fluctuations Part III The role of upwelling on fluctuations

The ecological relationship between fishes and their environment is of great practical application in fisheries. For any large scale development of our fishery resources a better understanding of the environmental factors influencing the reSources is essentia

Our fisheries resources and the role of upwelling in their fluctuations Part I marine fish production of India

The ecological relationship between fishes and their environment is of great practical application in fisheries. For any large scale development of our fishery resources a better understanding of the environmental factors influencing the reSources is essentia

Temperature scaling in a dense vibro-fluidised granular material

The leading order "temperature" of a dense two dimensional granular material fluidised by external vibrations is determined. An asymptotic solution is obtained where the particles are considered to be elastic in the leading approximation. The velocity distribution is a Maxwell-Boltzmann distribution in the leading approximation. The density profile is determined by solving the momentum balance equation in the vertical direction, where the relation between the pressure and density is provided by the virial equation of state. The predictions of the present analysis show good agreement with simulation results at higher densities where theories for a dilute vibrated granular material, with the pressure-density relation provided by the ideal gas law, are in error. The theory also predicts the scaling relations of the total dissipation in the bed reported by McNamara and Luding (PRE v 58, p 813).Comment: ReVTeX (psfrag), 5 pages, 5 figures, Submitted to PR

Distribution of larval tuna collected by the Carlsberg foundation's Dana expedition (1928-30) from the Indian Ocean

The geographical and seasonal distribution of larvae of five species of tuna (Katsuwonus elamis, Neothunnus macropterus, Euthynnus affinis affinis, Auxis thynnoides and Auxis thazard in the Indian Ocean based mainy on the collections made by the 1928-30 Dana Oceanographical Expedition are dealt with

Notes on eggs, larvae and juveniles of fishes from Indian waters XV Pegasus volitans Linnaeus. XVI Dactyloptena orientalis (Cuvier and Valenciennes) and XVII Ddactyloptena macracanthus (Sleeker)

Three species of pegasids viz., Pegasus volitans Linnaeus, P. laternarim Cuvier and P. draconis Linnaeus have been recorded from the seas around India. Of these, Pegasus draconis is distinct from the other two by the presence of 8 tail rings and 2 pits on occiput. P. volitans differs from P. laternarius mainly in having 12 tail rings as against 11 tail rings in the latter. P. natans is considered synonym of P. volitans (vide De Beaufort, 1962) and hence the larval and juvenile specimens collected from the Orissa coast (Jones and Pantulu, 1958) and the postlarva collected from Porto Novo (Krishnamurthy, 1962) should be known under P. volitans

The fishing industry of Minicoy Island with special reference to the tuna fishery

The coral island of Minicoy (Fig. 1 a and b) in the Indian Ocean (Latitude 8° 7' N., Longitude 73° 18' E.) is the most important tuna fishing centre in the Indian Union (Fig. 1). Situated between the two main groups of islands of the Laccadive and the Maldive Archipelagoes, it is about 10 km. long and 820 m. broad in the centre and has an area of about 455 hectares and population of about 4,000 who speak the same Mahl dialect as the Maldivians to whom they are related ethnically. The main port of trade in India for the islanders is Cannanore about 420 km. away on the Malabar coast and specially built sailing vessels known as odams are used for carrying men and cargo to the mainland and back. Tuna fishery is the most important industry of the island and the chief product of export is the mas min or the cured and dried meat of tuna the value of which has recently risen to the record figure of over half a million rupees a year. Export of cured tuna meat contributes about two-thirds of the total income of the islanders while next in order of importance comes the money remitted by those serving as lascars in merchant vessels. The only other source of income is from the sale of produce like copra, jaggery, coir and vinegar from coconuts. There is practically no other source of revenue and the inhabitants have to depend entirely on the mainland for all essential items and necessities of daily life such as rice and other commodities. In view of this, a barter system of trade prevails there and the necessary goods are supplied by certain merchants at Cannanore directly or through their agents stationed in the island