Articles by Keyword: Reproduction

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  1. Optimum temperature and inoculation levels for <em>in vitro</em> production of <em>Pratylenchus brachyurus</em> on carrot discs

    Optimum temperature and inoculation levels for <em>in vitro</em> production of <em>Pratylenchus brachyurus</em> on carrot discs

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Pratylenchus brachyurus is an economically important parasite of several agricultural crops, including potato, groundnut, maize and soybean. Large numbers of this species are required for research on pathogenecity, host plant resistance and efficacy of nematicides. The effect of inoculation density...
  2. Reproduction and recruitment patterns of the surf clam <em>Donax serra</em> (Bivalvia, Donacidae) on two Namibian sandy beaches

    Reproduction and recruitment patterns of the surf clam <em>Donax serra</em> (Bivalvia, Donacidae) on two Namibian sandy beaches

    Item type: Journal Article • Journal: South African Journal of Marine Science
    Reproduction and recruitment of the surf clam Donax serra on two Namibian beaches were studied over a period of two years. Histological examination of the gonads indicated a discontinous annual reproductive cycle, related to monthly mean sea surface temperature. The...
  3. A review of orange roughy <em>Hoplostethus atlanticus</em> fisheries, estimation methods, biology and stock structure

    A review of orange roughy <em>Hoplostethus atlanticus</em> fisheries, estimation methods, biology and stock structure

    Item type: Journal Article • Journal: South African Journal of Marine Science
    Orange roughy Hoplostethus atlanticus are unusual fish. They form dense aggregations that have fuelled lucrative fisheries at great depths (600–1 400 m), especially off Namibia, New Zealand and Australia. They are thought to be very long-lived (>100 years, maturity at...
  4. Some observations on the reproductive biology of The sixgill shark <em>Hexanchus griseus</em> (Bonnaterre, 1788) from southern African waters

    Some observations on the reproductive biology of The sixgill shark <em>Hexanchus griseus</em> (Bonnaterre, 1788) from southern African waters

    Item type: Journal Article • Journal: South African Journal of Marine Science
    Observations are made of the maturation status of 81 male and 88 female sixgill sharks Hexanchus griseus from southern African waters. Males mature at about 310 cm total length (TL) with the calcification of the terminal cartilage elements of the...
  5. Reproduction, growth and migrations of sei whales <em>Balaenoptera borealis</em> off the west coast of South Africa

    Reproduction, growth and migrations of sei whales <em>Balaenoptera borealis</em> off the west coast of South Africa

    Item type: Journal Article • Journal: South African Journal of Marine Science
    Results of the examination of 1 062 sei whales Balaenoptera borealis landed at the whaling station at Donkergat, Saldanha Bay, South Africa, in the 1962 and 1963 whaling seasons are presented. Sei whales were usually encountered off the edge of...
  6. POSSIBLE ADAPTIVE SIGNIFICANCE OF SEX RATIO AND SEXUAL DIFFERENCES IN SIZE AT MATURITY IN THE ORANGE RIVER LABEO, <em>LABEO CAPENSIS</em>

    POSSIBLE ADAPTIVE SIGNIFICANCE OF SEX RATIO AND SEXUAL DIFFERENCES IN SIZE AT MATURITY IN THE ORANGE RIVER LABEO, <em>LABEO CAPENSIS</em>

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    Labeo capensis spawns on inundated vegetation during flood periods. Suitable conditions for spawning are of short duration and do not allow time for extended breeding behaviour. The success of fertilisation is therefore probably independent of the size of males. This...
  7. AGE, GROWTH, REPRODUCTION AND MORTALITY OF THE BUTTER-CATFISH <em>EUTROPIUS DEPRESSIROSTRIS</em> (SCHILBEIDAE: PISCES) IN THE LUPHEPHE NWANEDZI IMPOUNDHENT, VENDA (SOUTH AFRICA)

    AGE, GROWTH, REPRODUCTION AND MORTALITY OF THE BUTTER-CATFISH <em>EUTROPIUS DEPRESSIROSTRIS</em> (SCHILBEIDAE: PISCES) IN THE LUPHEPHE NWANEDZI IMPOUNDHENT, VENDA (SOUTH AFRICA)

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    Aspects of the biology of Eutropius depressirostris in the Luphephe-Nwanedzi impoundment in north-east Venda (South Africa 30° 25' E, 23° 14' S) have been investigated. The Von Bertalanffy equation
  8. FURTHER OBSERVATIONS ON THE BREEDING BEHAVIOUR OF <em>LABEO UMBRATUS</em> (SMITH) (PISCES: CYPRINIDAE)

    FURTHER OBSERVATIONS ON THE BREEDING BEHAVIOUR OF <em>LABEO UMBRATUS</em> (SMITH) (PISCES: CYPRINIDAE)

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    Breeding behaviour of Labeo umbratus was observed in the Modder River, Orange Free State, and ova were collected from below the site and hatched. Fry were reared for 12 months to confirm the identification of the ova collected. The behaviour...
  9. DIET AND REPRODUCTIVE ACTIVITY OF THE ESTUARINE ROUNDHERRING <em>GILCHRISTELLA AESTUARIA</em> IN CUBHU, A FRESHWATER COASTAL LAKE IN NORTHERN NATAL, SOUTH AFRICA

    DIET AND REPRODUCTIVE ACTIVITY OF THE ESTUARINE ROUNDHERRING <em>GILCHRISTELLA AESTUARIA</em> IN CUBHU, A FRESHWATER COASTAL LAKE IN NORTHERN NATAL, SOUTH AFRICA

    Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences
    A study of the diet and reproductive activity of Gilchristella aestuaria revealed that active gonads were present throughout the year. The main breeding season appeared to be from spring through to autumn with two distinct peaks occurring from August to...
  10. A COMPARISON OF CYPRINID FISH POPULATIONS IN THREE LARGE TRANSKEI RESERVOIRS WITH RESPECT TO ABUNDANCE AND REPRODUCTION

    A COMPARISON OF CYPRINID FISH POPULATIONS IN THREE LARGE TRANSKEI RESERVOIRS WITH RESPECT TO ABUNDANCE AND REPRODUCTION

    Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences
    Gill net catches of fish in three turbid reservoirs (Lakes Xonxa and Lubisi on the Kei River system and Lake Umtata on the Mtata River) between 1982 and 1985 were dominated by two cyprinids the common carp, Cyprinus carpio, and...