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FISH POPULATIONS IN THE MIDDLE AND LOWER ORANGE RIVER, WITH SPECIAL REFERENCE TO THE EFFECTS OF STREAM REGULATION
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: J.A. Cambray --- Cape Department of Nature and Environmental Conservation, Republic of South AfricaThe results of two surveys, in March 1982 and September 1983, on the distribution and status of freshwater fish in the highly regulated section of the Orange River, from the P.K. Le Roux Dam wall to the mouth of the... -
Spatial variability in macroinvertebrate assemblages: comparing regional and multivariate approaches for classifying reference sites in South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: HelenF DallasSpatial variability in macroinvertebrate assemblages was examined with the aim of evaluating the utility of regional classification systems in aquatic bioassessment. Sampling was undertaken at reference sites in the Western Cape and Mpumalanga, South Africa, using the rapid bioassessment method... -
The food and feeding habits of five freshwater and brackish-water fish species in Nigeria
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: PO Ajah MN Georgewill MO AjahThe food and feeding habits of five economically important fresh-and brackish-water fishes, Channa obscura, Chrysichthys nigrodigitatus, Heterotis niloticus, Synodontis nigrita and Trachinotus maxillosus, were investigated. A number of techniques were used to carry out gut content analysis, including the Hynes... -
The role of ornamental goldfish Carassius auratus in transfer of some viruses and ectoparasites to cultured fish in Egypt: comparative ultra-pathological studies
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: MA Mahmoud --- Department of Pathology, Faculty of Veterinary Medicine, Egypt SM Aly --- , Egypt AS Diab --- , Egypt G. John --- Department of Biotechnology, IndiaGoldfish, common carp and Nile tilapia were sampled between September 2002 and May 2003 to investigate lesions induced by viral diseases and ectoparasites. Goldfish exhibited neoplasms, Dermocystidium sp., Ichthyophthirius multifiliis (Ich), Trichodina reticulata, Lernaea cyprinacea and systemic infections. Neoplastic and... -
Variability in growth of Vachellia nilotica provenances tested in the Sudano-Sahelian zone of Niger
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Mahamane Larwanou --- African Forest Forum, Kenya Rabiou Issa --- Institut Pratique de Développement Rural, Niger Mahamane Saadou --- Department of Biology, Faculty of Science, Niger Anders Ræbild --- Department of Geoscience and Natural Resources, DenmarkA provenance trial of Vachellia nilotica (Acacia nilotica) was conducted in Niger in order to assess variability in growth among 10 provenances from Africa (subsp. adstringens from Niger, Senegal and Cameroun) and outside the continent (subsp. indica from Pakistan and... -
Cattle and cattle colour terminology in South Africa
Item type: Journal Article • Journal: Anthropology Southern Africa • Authors: Louis J Louwrens --- Department of African Languages, Elsabé Taljard --- Department of African Languages,A comparison between cattle colour terminology found in the Khoikhoi languages and that found in South African Bantu languages brings noticeable similarities to light, leading to the assumption that both the cattle and the terms used to describe their characteristic... -
Is there a trade-off in resource allocation to condensed tannins and thorn defences in Vachellia (Acacia) species?
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Allan Sebata --- Department of Forest Resources and Wildlife Management, ZimbabweAcacia species invest in condensed tannins (CT) and thorn defences among others. Plant defences are considered costly because they use resources that would otherwise be available for growth and reproduction. To reduce plant defence costs it has been argued that... -
Effect of drift sampler exposure time and net mesh size on invertebrate drift density in the Njoro River, Kenya
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: PW Mureithi --- Department of Biological Sciences, Kenya JG Mbaka --- Department of Land and Water Management, Kenya CM M’Erimba --- Department of Biological Sciences, Kenya JM Mathooko --- Department of Biological Sciences, KenyaAlthough invertebrate drift is an important ecological process in lotic ecosystems, very little is known about it in Kenyan rivers. The primary aim of this study was to investigate the effect of driftnet mesh size and exposure duration on drift... -
Predictive modelling of the potential future distribution of Vachellia nilotica within the KwaZulu-Natal province of South Africa
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: Janet Taylor --- Natural Resources Section, KwaZulu-Natal Department of Agriculture and Rural Development, South Africa Nico Smit --- Department of Animal, Wildlife and Grassland Sciences, South Africa Debbie Jewitt --- Biodiversity Research and Assessment, Ezemvelo KZN Wildlife, South AfricaMany regions of South Africa are prone to woody plant thickening. This can have an ecologically detrimental effect on the open savannas and grasslands. KwaZulu-Natal, a province on the east coast of South Africa, is currently experiencing an increase in... -
Effect of dietary vitamin E on biochemical, oxidative stress and immunological parameters in Nile tilapia exposed to penoxsulam
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: TM Saber --- Forensic Medicine and Toxicology Department, Egypt M ElHady --- Fish Diseases and Management Department, Egypt HA Ali --- Department of Biochemistry, EgyptThis study was performed to determine the median lethal concentration (96-h LC50) of penoxsulam (PNX) in Nile tilapia, Oreochromis niloticus, fingerlings and to investigate the protective effect of vitamin E (Vit E) against biochemical and immunological alterations induced by two... -
Relative growth of invasive and indigenous tilapiine cichlid fish in Tanzania
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: SJ Bradbeer --- , United Kingdom BP Ngatunga --- , Tanzania GF Turner --- , United Kingdom MJ Genner --- , United KingdomNon-native species have been widely distributed across Africa for the enhancement of capture fisheries, but it can be unclear what benefits in terms of fisheries production the non-native species bring, compared with native species. Here we compared the relative growth... -
Cyanobacterial abundance and microcystins in water, seston and fish tissues in Lake Hora-Arsedi (Ethiopia)
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: TW Zewde --- , Ethiopia D Kifle --- , Ethiopia JA Johansen --- , Norway TB Demissie --- , Ethiopia JH Hansen --- , Norway Z Tadesse --- , EthiopiaThe phytoplanktonic composition with a focus on cyanobacteria, intra- and extracellular microcystins (MCs) concentrations and MCs concentrations in fish tissues were investigated in Lake Hora-Arsedi (Ethiopia). The phytoplankton community comprised of 40 species in the first phase of the study... -
Description of the tadpoles of two Cameroonian frogs, Leptodactylodon axillaris and L. perreti (Anura: Arthroleptidae)
Item type: Journal Article • Journal: African Journal of Herpetology • Authors: Deise Cruz --- California Academy of Sciences, USA AnneliseL. Dawson --- Harvard University, USA DavidC. Blackburn --- California Academy of Sciences, USAWe describe the tadpoles of two closely related frog species of the genus Leptodactylodon (family Arthroleptidae), L. axillaris and L. perreti, that are restricted to the mountains of Cameroon. Tadpoles were collected from near the type locality of each species... -
DNA barcoding of five economically important freshwater fish species from the Nile River, Sudan
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: Asma Mahmoud Hamza --- University of Kassala, Sudan Amna Taj Elsir Mahjoub Mohammed --- University of Kassala, SudanThe study was conducted to barcode five freshwater fish species obtained from Nile River tributaries (the Atbara River and the Blue Nile), in March 2019, using analysis of partial CO1 gene sequences. Fish samples were identified morphologically as Nile perch...