Articles by Keyword: Population Structure

Search results for Population Structure

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  1. VIABLE HETEROTROPHIC BACTERIAL POPULATION STRUCTURE OF A TURBID MAN-MADE IMPOUNDMENT

    VIABLE HETEROTROPHIC BACTERIAL POPULATION STRUCTURE OF A TURBID MAN-MADE IMPOUNDMENT

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    Seventy one heterotrophic bacterial isolates were obtained from Wuras Dam, phenotypically characterized and clustered with the unweighted-pair group method. Three groups were obtained of which the first contained 59 members in several clusters. Overall this group was characterized by a...
  2. POPULATION DYNAMICS AND DEMOGRAPHY OF AN ESTUARINE COPEPOD (<em>PSEUDODIAPTOMUS EESSEI</em>) IN LAKE SIBAYA, A SUBTROPICAL FRESHWATER COASTAL LAKE

    POPULATION DYNAMICS AND DEMOGRAPHY OF AN ESTUARINE COPEPOD (<em>PSEUDODIAPTOMUS EESSEI</em>) IN LAKE SIBAYA, A SUBTROPICAL FRESHWATER COASTAL LAKE

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    Population size and stage structure of Pseudodiaptomus hessei (Mrázek) was studied over 27 months at a single site in subtropical Lake Sibaya. Population density varied seasonally from about 1 to 4 individuals per litre, but a fairly stable population structure...
  3. Effects of previous cultivation on regeneration of <em>Julbernadia globiflora</em> and <em>Brachystegia spiciformis</em> in grazing areas of Mupfurudzi Resettlement Scheme, Zimbabwe

    Effects of previous cultivation on regeneration of <em>Julbernadia globiflora</em> and <em>Brachystegia spiciformis</em> in grazing areas of Mupfurudzi Resettlement Scheme, Zimbabwe

    Item type: Journal Article • Journal: African Journal of Range & Forage Science
    We investigated the effects of previous cultivation on regeneration potential under miombo woodlands in a resettlement area, a spatial product of Zimbabwe's land reforms. We predicted that cultivation would affect population structure, regeneration, recruitment and potential grazing capacity of rangelands...
  4. A preliminary quantitative assessment of gillnet fishing in subtropical Lake Tzaneen, Northern Province, South Africa

    A preliminary quantitative assessment of gillnet fishing in subtropical Lake Tzaneen, Northern Province, South Africa

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    Between January 1998 and January 1999 a quantitative investigation was done on the fish populations of Lake Tzaneen, Northern Province, South Africa. Two graded series of multi-filament gillnets were set overnight every six weeks capturing 14 species of fish. Of...
  5. Reproductive strategy of <em>Labeo senegalensis</em> Valenciennes 1842 (Teleostei: Cyprinidae) in the Ouémé basin, Benin

    Reproductive strategy of <em>Labeo senegalensis</em> Valenciennes 1842 (Teleostei: Cyprinidae) in the Ouémé basin, Benin

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    Aspects of the reproductive biology and population structure of Labeo senegalensis were investigated in the Ouémé River between April 2005 and March 2006. Reproductive strategy was investigated using gonadosomatic index, ovarian structure and fecundity. Average size-at-first-maturity (L 50) was estimated...
  6. Response of mangroves to drought and non-tidal conditions in St Lucia Estuary, South Africa

    Response of mangroves to drought and non-tidal conditions in St Lucia Estuary, South Africa

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    The effect of a prolonged closed-mouth state on the condition of mangrove habitats was studied in May 2010 at St Lucia Estuary, KwaZulu-Natal. The mouth had been closed to the sea since 2002 as a result of artificial mouth closure...
  7. Observations on the Ecology of <em>Pleurobrachia Pileus</em> (Ctenophora) in the Southern Benguela Ecosystem

    Observations on the Ecology of <em>Pleurobrachia Pileus</em> (Ctenophora) in the Southern Benguela Ecosystem

    Item type: Journal Article • Journal: African Journal of Marine Science
    The vertical distribution, abundance and size composition of a population of Pleurobrachia pileus was studied during a six-day drogue study conducted off the west coast of South Africa in February 1995. The population was centred in deep water, possibly because...
  8. Euphausiid population structure and grazing in the Antarctic Polar Frontal Zone — austral autumn 2004

    Euphausiid population structure and grazing in the Antarctic Polar Frontal Zone — austral autumn 2004

    Item type: Journal Article • Journal: African Journal of Marine Science
    The euphausiid community structure and grazing dynamics were investigated in the West Indian sector of the Polar Frontal Zone during the austral autumn 2004. Subsurface (200m) temperature profiles indicated that an intense frontal feature, formed by the convergence of the...
  9. The reproductive style of <em>Diplodus capensis</em> (Sparidae) in southern Angola: rudimentary hermaphroditism or partial protandry?

    The reproductive style of <em>Diplodus capensis</em> (Sparidae) in southern Angola: rudimentary hermaphroditism or partial protandry?

    Item type: Journal Article • Journal: African Journal of Marine Science
    The reproductive style of Diplodus capensis was examined in an unexploited coastal area in southern Angola. The mean length of females was significantly greater than that of males and, although not significant, females dominated the older age classes. The overall...
  10. The biology of Barnard's dentex, <em>Dentex barnardi</em> (Teleostei: Sparidae), in southern Angola

    The biology of Barnard's dentex, <em>Dentex barnardi</em> (Teleostei: Sparidae), in southern Angola

    Item type: Journal Article • Journal: African Journal of Marine Science
    Barnard's dentex Dentex barnardi is a relatively slow-growing, late-maturing species with an intermediate longevity (maximum recorded age = 13 years). The length and age structures of the population were similar for males and females; however, the sex ratio was female...