34 resultados para employment records
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.
Resumo:
In two previous papers, the Eurotatorian fauna of Sri Lanka has been systematically dealt with. Description of 104 species is given in the previous papers. In the present study an additional twenty-two species are described. Of these two are new. The composition of the Sri Lanka Rotifera is discussed in relation to the fauna of other parts of the world. The distribution of the species in different types of habitats is studied on the basis of samples. A complete list of all Rotifera recorded from Sri Lanka so far is given for easy reference. Examples of localities where species were collected are also given.
Resumo:
Descriptions with suitable illustrations of two species of palaemonid prawns - Macrobrachium aemulum and Palaemon (Palaemon) concinnus are furnished. M. aemulum has been enjoying an isolated distribution in New Caledonia. It is reported for the first time from India and is therefore a clear case of discontinuous distribution. Studies revealed that M. aemulum is distinct from M. nobilii and the reasons for separating the two species are discussed. New distributional records for P. (P.) concinnus in the south-west coast of India are also given.
Resumo:
This paper describes six species of polychaete worms, which are new records from Pakistan. The species are: Arabella iricolor (Montagu), Capitella capitata (Fabricius), Mesochaetopterus sagittarius (Claparede), Phyllochaetopterus herdmani Willey, Lysidice natalensis Kinberg and Marphysa depressa (Schmarda).