922 resultados para Fauna records
Resumo:
This paper with the systematic study of three species of mysids, collected by R/V "Dr. Fridtjof Nansen", which are new to the northern Arabian Sea. The three species described and illustrated are: Siriella affinis Hansen, Afromysis macropsis Tattersal and Acanthomysis quadrispinosa Nouvel.
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Members of the family Oxycephalidae are quite common in the offshore waters of Pakistan, but no previous attempt has been made to study them. Nine species belonging to six genera are recorded from Pakistan waters (22°09′ to 25°21′N and 61°35′ to 67°55′E). The material was taken by R/V Dr. Fridtjof Nansen, during 1977. A descriptive account along with identification key to the genera is provided.
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Freshwater animals are of importance in the economy of most countries. In recent years the scientific cultivation of freshwater fish for food has been spreading throughout South-East Asia and the Far-East. New and useful species of fish have been introduced into many countries including Ceylon where the older system of trapping any variety of fish that is available is being replaced by scientifically planned management with a view to increasing the production of good quality fish. Considerable quantities of food mainly in the form of fish are being taken from our freshwaters, providing a cheap source of much needed protein in the diet of the villager. More recently large quantities of freshwater fish are being consumed by the urban population.
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Retting of coconut husk is one of the major problems of pollution in the estuaries (kayals) of Kerala. Retting activity has resulted in the mass destruction of the flora and fauna and has converted sizeable sections of the kayal into virtual cesspools of foul smelling stagnant waters. Levels of hydrogen sulphide, phosphate and BOD, increased while dissolved oxygen and fish and shellfish fauna decreased in the ambient waters. In the Kadinamkulam kayal a total of 37 species of fishes belonging to 26 families, 5 species of prawn and 2 species each of crabs and molluscs were recorded from the no retting zone, whereas only 20 species of fish in dead condition were collected from the rating zone. Prawns, crabs and molluscs were absent at the vetting zone. Majority of the fish fauna in the kayal were marine forms.
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This is the first of a series consequent to "A guide to the freshwater fauna of Ceylon" by A. S. Mendis and C. H. Fernando, Bull. Fish. Res. Stn. Ceylon No. 12, 160 pp. (1962). The purpose of this series is to make the above-mentioned work more comprehensive. The present supplement is restricted to the Arthropoda.
Resumo:
This is the second supplement to "A guide to the freshwater fauna of Ceylon" by A. S. Mendis and C. H. Fernando, Bull. Fish. Res. Stn., Ceylon, No. 12, 160 pp. (1962). In the present supplement additions and corrections are made in the sections on Protozoa, Annelida and Arthropoda. The sections on Platyhelrainthes and Nematoda have been expanded and the Acanthocephala added. A list of species recorded and the hosts of the parasitic forms are included. In the "Guide", the insects with only larval stages in aquatic habitats were mentioned only briefly and no species lists were included. In this supplement this gap is largely filled by added notes and inclusion of species lists of all these groups except the Neuroptera, Lepidoptera, Tabanidae, Syrphidae and Stratiomyidae. The orders Neuroptera and Lepidoptera have relatively few members in freshwater habitats and the families Tabanidae, Syrphidae and Stratiomyidae have forms with larvae in aquatic habitats and also in moist places which are not true freshwater habitats. At this time, it is not possible to separate those forms living in freshwater habitats. Short diagnoses of six additional families are given, namely, the ixidae, Psychodidae, Tabanidae Stratiomyidae, Rhagionidae and Sciomyzidae. Keys are provided for the Odonata and Ephermeroptera larvae down to the family level. An attempt has been made to make the references more comprehensive. Works dealing specifically with the Ceylonese fauna are of course included, but in addition those which are of use in diagnosis of local genera and species have been cited.
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This paper records the results of investigations of plankton, benthic fauna and fish fauna carried out between 1957 and 1963. The standing crop of net plankton in the lake was found to be 249.6 Kg/ha. This plankton is not being fully utilized by the fish fauna in the lake. Stocking the lake with a plankton feeder like Chanos chanos (Forskal) is recommended. The figure of 24.37 Kg/ha obtained for the standing crop of bottom fauna in the lake was comparatively low. This indicates that the bottom fauna is being fully utilized by the fish. The introduction and establishment of Tilapia mossambica (Peters) had not wiped out a single indigenous species of fish from the lake that produces about 2,000 lbs. of fish per acre per year. This can be increased by the introduction of a plankton feeder (Chanos chanos), and by further exploitation of existing stock.
Resumo:
Three nematodes, two acanthocephalans and three cestodes were collected by dissecting 15 species of fish. Of these parasites only Hedruris sp. a larval nematode is responsible directly for the death of fish, since it is found in predatory species a reduction of these might prove of considerable consequence to fish, production. Bothriocephalus gowleonensis, a cestode probably introduced from China with Chinese carp, was recorded in an indigenous carp Puntius sarana. This parasite causes heavy mortality in grass carp in China and is a potential danger to local species. A single crustacean parasite was recorded. It is likely that they are widespread. No protozoa were recorded but there can be little doubt that they occur in local freshwater species and may be of considerable importance in fisheries. Several predators (insects, fish and other vertebrates) were recorded and are doubtless of considerable importance. However, the role of parasites and of predators (especially fishes) in relation to the productivity of fisheries can hardly be assessed at present and needs further study. A study of the fauna found at the shallow edges of 21 irrigation reservoirs showed an abundance of fauna in the low-country reservoirs whilst the up-country reservoirs had a poor fauna. The fauna showed insects, crustacea and mollusca in this order of abundance. The presence of insect and molluscs feeding fish in our fauna shows that these rich sources of food are being utilised.
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In the first paper of this series, Chengalath and Fernando (1973) dealt with the genus Lecane from Sri Lanka. In all, twenty five species were recorded, of which seventeen species were new records. Two new species were also described. On the present paper the authors deal with the rest of the Eurotatoria. Again they have found many new records. In all 79 species are described in the present paper of which 47 are new records. The present study is based on the examination of over 300 samples from 135 localities including large and small tanks, ponds of various sizes, rice fields, streams and marshes. The collections cover the whole area of Sri Lanka and were taken during different seasons of the year mainly from 1968-1972.
Resumo:
Among the commercially valuable species occurring in Lake Victoria the two endemic species of Tilapia, T. esculenta (Graham) and T. variabilis (Boulenger) still provide the basis for the fishery in many areas, though in some places the non-cichlid species are more important, for example in the Kagera river area where large numbers of Labeo victorianus and Schilbe mystus migrate seasonally into the river. Although certain species show these habitat preferences. Most of the coastline of Lake Victoria supports a wide variety of species, all of which contribute to the commercial fishery. Over the past ten years the East African Fisheries Research Organisation has fished experimentally a number of stations within a radius of fifty miles from Jinja. These stations have been selected so as to cover a variety of habitats which range from sheltered bays to exposed coastlines. The records discussed in this paper are the result of fishing operations carried out in Pilkington Bay over the period December 1954 to November 1956. This series of fishing operations was carried out in an attempt to assess the composition of the fish populations contained in this area. To this end a variety of nets of differing mesh sizes were used. Pilkington Bay is about ten square miles in extent and is an irregular and deep indentation on the north coast of Buvuma Island. It lies within the sleeping siclmess area where fishing by Africans is prohibited. When selecting an experimental fishing ground, it is important to have some idea of the amount of commercial fishing being carried out in the area. Throughout the period of this experiment a few African fishermen were seen operating illegally in the area, but it is unlikely that their efforts greatly affected the results obtained. Pilkington Bay was fished by E.A.F.R.O. in 1949 and 1950 (Lowe McConnell 1956) but since then till the present experiment, fishing in the area has been infrequent.
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An estimation of the total industrial catch of the shallow water shrimp by-catch for the period 1986-1990 is presented. By-catch species compositions based on landings and onboard samples at ex-Emopesca/Beira (Marbeira) and Pescamar are also presented. The by-catch is essentially composed by 2nd and 3rd commercial fish categories, other crustaceans and cephalopods appearing in varying proportions in the catch. The total catch of shrimp by-catch estimated for the period is approximately 17 to 25 thousand tons per year.
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Catch composition and bathymetric distribution of demersal fish caught along the coast of Mozambique between parallels 16 degree 20' and 19 degree 30' S at depths of 11 to 180 metres are given. The shrimp by-catch was also studied.
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This report of the research cruise (7 to 23 June 1981) surveying pelagic marine resources of the Sofala Bank (Mozambique) describes the size composition, distribution, length-weight relationships and sex-ratio of the fish captured. Decapterus russellii, D. macrosoma, Selar crumenophthalmus and Rastrelliger kanagurta represented 21.7% of the total catch. The by-catch was also studied.
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This report of the research cruise (21 July to 7 August, 1981) surveying pelagic marine resources of the Sofala Bank (Mozambique) describes size composition distribution, length-weight relationships and sex-ratio of the fish captured. Decapterus russellii, D. macrosoma, Selar crumenophthalmus and Rastrelliger kanagurta represented 21.7% of the total catch. The by-catch was also studied.
Resumo:
This cruise report describes the Sofala Bank (Mozambique) crustacean stocks and the fish by-catch. A survey was made of the stock assessment of demersal fish with commercial interest, fishing grounds, biology and distribution of the most abundant demersal fishes and the specific composition of trawl catch areas.