Articles by Author: Thomas Hecht

Search results for Thomas Hecht

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  1. Urban Aquaculture

    Urban Aquaculture

    Item type: Journal Article • Journal: African Journal of Aquatic Science
  2. Reproductive biology of a riverine cyprinid, <em>Labeo umbratus</em> (Teleostei: Cyprinidae), in small South African reservoirs

    Reproductive biology of a riverine cyprinid, <em>Labeo umbratus</em> (Teleostei: Cyprinidae), in small South African reservoirs

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    The reproductive and recruitment characteristics of moggel, Labeo umbratus, populations were examined in four small South African reservoirs. Reproduction, characterised by an extended spawning season, high fecundity, short incubation time and rapid larval development, appears to be ideally suited to...
  3. The distribution and abundance of the endangered Knysna seahorse <em>Hippocampus capensis</em> (Pisces: Syngnathidae) in South African estuaries

    The distribution and abundance of the endangered Knysna seahorse <em>Hippocampus capensis</em> (Pisces: Syngnathidae) in South African estuaries

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    The occurrence, distribution and abundance of the endangered Knysna seahorse Hippocampus capensis in 10 estuaries on South Africa's warm temperate south coast, were investigated. Seahorses were found only in the Knysna, Swartvlei and Keurbooms estuaries. Sex ratios were even and,...
  4. The life history and fishery potential of <em>Labeo umbratus</em> (Teleostei: Cyprinidae) in five small South African reservoirs

    The life history and fishery potential of <em>Labeo umbratus</em> (Teleostei: Cyprinidae) in five small South African reservoirs

    Item type: Journal Article • Journal: African Journal of Aquatic Science
    The life histories of five populations of moggel, Labeo umbratus, inhabiting small Eastern Cape reservoirs were compared and the differences related to environmental parameters. A significant positive correlation between fish growth and chlorophyll a was noted in four cases. In...
  5. Does the endangered Knysna seahorse, <em>Hippocampus capensis</em>, have a preference for aquatic vegetation type, cover or height?

    Does the endangered Knysna seahorse, <em>Hippocampus capensis</em>, have a preference for aquatic vegetation type, cover or height?

    Item type: Journal Article • Journal: African Zoology
    The Knysna seahorse, Hippocampus capensis, is an endangered teleost confined to three South African estuaries. Its abundance within these systems is low and distributions are patchy. Consequently, monitoring population sizes is labour-intensive. The aim of this study was to establish...
  6. Establishment of <em>stylosanthes guyanensis</em> in marandellas sandveld

    Establishment of <em>stylosanthes guyanensis</em> in marandellas sandveld

    The feasibility of establishing perennial forage legumes in veld has been investigated at Grasslands Research Station, Marandellas. Of the species tested, Stylosanthes guyanensis (stylo) appeared most suitable.
  7. A method of age determination for the South West African pilchard <em>Sardinops ocellata</em>

    A method of age determination for the South West African pilchard <em>Sardinops ocellata</em>

    Item type: Journal Article • Journal: South African Journal of Marine Science
    A method of age determination, based on recent research on growth and ring formation, is described for the pilchard of South West Africa. Dates of ring formation from 1971 to 1981 are documented. Illustrated examples of otolith interpretations are given.
  8. Evaluation of the effects of scorching caused by the directed application of a paraquat-containing herbicide mixture to the base of maize plants at various ages

    Evaluation of the effects of scorching caused by the directed application of a paraquat-containing herbicide mixture to the base of maize plants at various ages

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    The effect of herbicides which scorched the lower leaves of maize was compared in three seasons. The first season was relatively dry whilst the other two were wetter seasons. A mixture of cyanazine + atrazine + paraquat + a wetting...
  9. Growth of Cape horse mackerel <em>Trachurus trachurus capensis</em> off South Africa

    Growth of Cape horse mackerel <em>Trachurus trachurus capensis</em> off South Africa

    Item type: Journal Article • Journal: South African Journal of Marine Science
    Recent studies have provided evidence that the Cape horse mackerel Trachurus trachwus capensis in South African waters is a unit stock. Therefore, an age and growth study of the entire stock throughout its distributional range was undertaken in 1988/89. Growth...
  10. Chemical control of some broadleaved weeds which grow during winter in untilled maize lands

    Chemical control of some broadleaved weeds which grow during winter in untilled maize lands

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Several experiments have been done at Cedara in attempts to control broadleaved weeds in unfilled lands during winter. A number of herbicide treatments were tested on Conyza spp., Coronopus didymus, Gnaphalium spp., Hypochoeris radicata, Oenothera rosea and Taraxacum officinale. Where...