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  1. No Access

    Chapter and Conference Paper

    Consumption, Assimilation and Energy Balance in the Three-Spot Swimming Crab, Ovalipes Punctatus (de Haan) (Crustacea; Brachyura)

    The swimming crab Ovalipes punctatus (de Haan) is commonly found on the sandy beaches of the south and east coasts of South Africa. These crabs prey extensively on the bivalve and gastropod populations which occu...

    H. H. Du Preez in Sandy Beaches as Ecosystems (1983)

  2. No Access

    Article

    Nitrogen and energy loss via nonfaecal and faecal excretion in the marine teleost Lithognathus lithognathus

    Nitrogen excretion and assimilation efficiencies of individual Lithognathus lithognathus (Cuvier 1830), a marine teleost from high energy surf zones in Algoa Bay, South Africa, were determined under laboratory co...

    A. C. Cockcroft, H. H. Du Preez in Marine Biology (1989)

  3. No Access

    Article

    Bioenergetics of fishes in a high-energy surf-zone

    Energy budgets are proposed for four teleost and two elasmobranch species as well as for the main icthyofauna groups for a surf-zone ecosystem. The ecology of surf-zone fishes of eastern Cape beaches, Algoa Ba...

    H. H. Du Preez, A. McLachlan, J. F. K. Marais, A. C. Cockcroft in Marine Biology (1990)

  4. No Access

    Article

    Effect of manganese and iron at a neutral and acidic pH on the hematology of the banded tilapia (Tilapia sparrmanii)

    V. Wepener, J. H. J. Van Vuren… in Bulletin of Environmental Contamination an… (1992)

  5. No Access

    Article

    Bioaccumulation of manganese in selected tissues of the freshwater crab, Potamonautes warreni (Calman), from industrial and mine-polluted freshwater ecosystems

    Manganese concentrations in water and sediments of the Bronkhorstspruit River, Nooitgedacht Dam and especially in the Natalspruit River, did not fall within stated limits for the protection of aquatic life. Ti...

    V. E. Steenkamp, H. H. du Preez, H. J. Schoonbee, P H. van Eeden in Hydrobiologia (1994)

  6. No Access

    Article

    The influence of suspended silt on oxygen consumption by the redbreast tilapia, Tilapia rendalli (Boulenger,1896)

    The routine oxygen consumption of redbreast tilapia, Tilapia rendalli exposed to silt from the Phalaborwa Barrage was investigated under controlled laboratory conditions. Exposure of adult fish to sublethal conce...

    H. H. du Preez, Y. Buermann, G. J. Steyn, L. Smit in Hydrobiologia (1996)

  7. No Access

    Article

    Concentrations of zinc in Barbus marequensis from the lower Olifants River, Mpumalanga, South Africa

    Zinc was detected in all the tissues examined, but in variable concentrations. The highest zinc concentrations were detected in the skin and ovaries. These zinc concentrations also differed significantly from ...

    T. Seymore, H. H. du Preez, J. H. J. van Vuren in Hydrobiologia (1996)

  8. No Access

    Article

    Tolerance levels of redbreast tilapia, Tilapia rendalli (Boulenger, 1896) to natural suspended silt

    Tilapia rendalli was exposed to various siltconcentrationsfor different exposure periods to determine LC50 andsublethalconcentration ranges. The extent of damaging effects, if any,ofsuspended silt on the exposed ...

    Y. Buermann, H. H. Du Preez, G. J. Steyn, L. Smit in Hydrobiologia (1997)