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Age and growth of two populations of West Coast steenbras Lithognathus aureti in Namibian waters, based on otolith readings and mark-recapture data
Item type: Journal Article • Journal: South African Journal of Marine Science • Authors: J. A. Holtzhausen C. H. KirchnerAge and growth of West Coast steenbras Lithognathus aureti, sampled from two separate populations (northern and southern) along Namibia's coast, was determined using sectioned otoliths, and the results were validated using mark-recapture data. For both populations, the special three-parameter Von... -
AGE, GROWTH, REPRODUCTION AND MORTALITY OF THE BUTTER-CATFISH EUTROPIUS DEPRESSIROSTRIS (SCHILBEIDAE: PISCES) IN THE LUPHEPHE NWANEDZI IMPOUNDHENT, VENDA (SOUTH AFRICA)
Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa • Authors: T. Hecht --- Department of Zoology, South AfricaAspects 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 -
Age, growth rate and size at sexual maturity of Labeobarbus aeneus (Teleostei: Cyprinidae) in the middle Vaal River, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: R Gerber --- Centre for Aquatic Research, Department of Zoology, South Africa NJ Smit --- Centre for Aquatic Research, Department of Zoology, South Africa GM Wagenaar --- Centre for Aquatic Research, Department of Zoology, South AfricaAge structure, growth and size at sexual maturity of smallmouth yellowfish, Labeobarbus aeneus (Burchell), were assessed in 2008–2009. Despite its angling and food importance, little has been published on many aspects of its ecology and biology, specifically its age structure... -
Do dart tags suppress growth of dusky kob Argyrosomus japonicus?
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: MH Griffiths CG AttwoodGrowth rates of dusky kob Argyrosomus japonicus calculated from mark-recapture and otolith-reading methods were compared. Mark-recapture data showed that A. japonicus are resident in an area between the Breede River Estuary and Cape Agulhas on the south-east coast of South... -
Validation of growth zone deposition rate in otoliths and scales of flathead mullet Mugil cephalus and freshwater mullet Myxus capensis from fish of known age
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: BR Ellender --- Department of Ichthyology and Fisheries Science, South Africa GC Taylor --- Department of Ichthyology and Fisheries Science, South Africa OLF Weyl --- , South AfricaFlathead mullet Mugil cephalus and freshwater mullet Myxus capensis are important components in South African estuarine fish communities and fisheries, but there is little information on their age and growth or age validation. This study validated the periodicity of growth... -
Age estimation, growth rate and size at sexual maturity of tigerfish Hydrocynus vittatus from the Okavango Delta, Botswana
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: R Gerber --- Centre for Aquatic Research, Department of Zoology, South Africa NJ Smit --- Centre for Aquatic Research, Department of Zoology, South Africa GM Pieterse --- Centre for Aquatic Research, Department of Zoology, South Africa D Durholtz --- , South AfricaThe aims of this study were to determine relative age, growth rate and size at maturity of tigerfish in the Okavango Delta as a basis for the development of a fisheries management plan. A total of 206 tigerfish Hydrocynus vittatus,... -
A retrospective assessment of the stock status of Otolithes ruber (Pisces: Sciaenidae) as bycatch on prawn trawlers from KwaZulu-Natal, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: JM Olbers ST FennessyThe sciaenid fish Otolithes ruber commonly occurs as bycatch in prawn trawl catches along the East African coast. Most of the trawl catches of this species are discarded because of their low commercial value. In order to evaluate the stock... -
Otoliths and vertebrae as potential hard structures for ageing South African yellowfin tuna Thunnus albacares
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: JD Filmalter --- Department of Ichthyology and Fisheries Science, South Africa OLF Weyl --- Department of Ichthyology and Fisheries Science, South Africa W Sauer --- Department of Ichthyology and Fisheries Science, South AfricaSagittal otoliths and vertebrae from 46 yellowfin tuna Thunnus albacares (118-175 cm fork length) collected off the west coast of South Africa were assessed for potential usefulness in age estimation. Growth increments were found on both structures. Comparisons of growth... -
A morphological description of the sagittal otoliths of two mormyrids, Marcusenius macrolepidotus and Petrocephalus catostoma (Family: Mormyridae)
Item type: Journal Article • Journal: African Zoology • Authors: N.N. Nicolaai --- Department of Zoology and Biology, South Africa A. Jooste --- Department of Zoology and Biology, South AfricaThe morphology of the sagittal otoliths of two South African mormyrid fish, Marcusenius macrolepidotus and Petrocephalus catostoma, were studied to determine possible morphological significance. The sagittae of M. macrolepidotus and P. catostoma are kidney-shaped and oblong, respectively. The ventral margin... -
Age and growth of the estuarine-dependent sparid Acanthopagrus berda in northern KwaZulu-Natal, South Africa
Item type: Journal Article • Journal: African Zoology • Authors: N. C. James --- Oceanographic Research Institute, South Africa B. Q. Mann --- Oceanographic Research Institute, South Africa L. E. Beckley --- Oceanographic Research Institute, South Africa A. Govender --- Oceanographic Research Institute, South AfricaAges were estimated for the tropical sparid, Acanthopagrus berda, caught in northern KwaZulu-Natal estuaries. Whole otoliths were used in the age determination. Age estimates were validated by marginal increment analysis and oxytetracycline labelling, which indicated that opaque deposition occurs primarily... -
Pycnoclavella (Tunicata: Ascidiacea) species from the West Indian Ocean
Item type: Journal Article • Journal: African Zoology • Authors: Patricia Kott --- Queensland Museum, AustraliaThree new Pycnoclavella species, recorded from a number of locations in Algoa and Plettenberg bays, suggest an unusual diversity for this genus in South African waters and indicate the extent to which the fauna of this part of the world... -
Otoliths versus scales: evaluating the most suitable structure for ageing largemouth bass, Micropterus salmoides, in South Africa
Item type: Journal Article • Journal: African Zoology • Authors: G.C. Taylor --- Department of Ichthyology and Fisheries Science, South Africa O.L.F. Weyl --- Centre for Invasion Biology, South African Institute for Aquatic Biodiversity, South AfricaThe suitability of scales for ageing Micropterus salmoides was determined by comparing the precision of growth zone counts on scales with those obtained from sectioned sagittal otoliths from a sample of 496 fish collected from Wriggleswade and Mankazana Impoundments in... -
Determining the most suitable method of otolith preparation for estimating the age of tigerfish, Hydrocynus vittatus in the Pongolapoort Dam, South Africa
Item type: Journal Article • Journal: African Zoology • Authors: M. Soekoe --- Department of Zoology, South Africa F. H. van der Bank --- Department of Zoology, South Africa N. J. Smit --- North-West University, PotchefstroomThis study compares sectioned and whole lapillus and asterisci otoliths as suitable structures for ageing tigerfish, Hydrocynus vittatus. Fifty tigerfish were collected from the Pongolapoort Dam, KwaZulu-Natal, South Africa. Growth zone counts on sectioned lapilli showed the greatest percentage agreement... -
Insights into the diet of a poorly known species: pygmy killer whale Feresa attenuata from Cape Verde, West Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: PR O'Dwyer --- Marine Biodiversity Research Group, Ireland S Berrow --- Marine Biodiversity Research Group, Ireland P López-Suárez --- Bios, C Oujo Lamao --- Bios,Despite having a worldwide distribution in tropical waters, knowledge on pygmy killer whales Feresa attenuata, including diet, is poor, with only a few studies carried out to date. The presence of otoliths and beaks in stomachs that have been examined... -
Otolith features and growth of juvenile Opsaridium microcephalum (Pisces: Cyprinidae) from the southwestern shoreline of Lake Malawi
Item type: Journal Article • Journal: African Zoology • Authors: Shinsuke Morioka --- Department of Aquaculture and Fisheries Science, Bunda College of Agriculture, MalawiSanjika, Opsaridium microcephalum, were collected from two sites (Nkhotakota and Chia) along the southwestern shoreline of Lake Malawi. The sagitta of the otolith was arrowhead-shaped with an obvious nucleus. Increments in the sagittae were observable until the bases of the... -
Validation of growth zone deposition in otoliths of two large endemic cyprinids in Lake Gariep, South Africa
Item type: Journal Article • Journal: African Zoology • Authors: Henning Winker --- Department of Ichthyology and Fisheries Science, South Africa Bruce R. Ellender --- Department of Ichthyology and Fisheries Science, South Africa Olaf L.F. Weyl --- South African Institute for Aquatic Biodiversity, South Africa Anthony J. Booth --- Department of Ichthyology and Fisheries Science, South AfricaWe tested the hypothesis that growth zones in the astericus otoliths of smallmouth yellowfish (Labeobarbus aeneus) and Orange River mudfish (Labeo capensis) were deposited annually. Two methods, fluorochrome marking and edge analysis of otoliths were used. For fluorochrome marking, specimens... -
Daily growth of young-of-the-year of the Baringo tilapia, Oreochromis niloticus baringoensis (Trewavas, 1983)
Item type: Journal Article • Journal: African Zoology • Authors: Chrisphine S. Nyamweya --- Lake Baringo Laboratory, Kenya Marine and Fisheries Research Institute, Kenya Chrisestom M. Mlewa --- Department of Fisheries and Aquatic Sciences, Kenya Charles C. Ngugi --- Department of Fisheries and Aquatic Sciences, Kenya Boaz Kaunda-Arara --- Department of Fisheries and Aquatic Sciences, KenyaOtolith microstructure analysis was used to validate microincrement deposition rate and to determine daily growth rates of young-of-the-year (YOY) Baringo tilapia, Oreochromis niloticus baringoensis. Microincrement formation was validated as daily by correlating the number of circuli on otoliths with the... -
Age and growth of Cape stumpnose Rhabdosargus holubi (Pisces: Sparidae) in the Eastern Cape, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: MW Farthing --- Department of Ichthyology and Fisheries Science, South Africa NC James --- South African Institute for Aquatic Biodiversity, South Africa WM Potts --- Department of Ichthyology and Fisheries Science, South AfricaRhabdosargus holubi is a small (maximum weight=2.4 kg) yet important fishery species in the estuaries of the south-east coast of South Africa. Little is known of its biology and specifically its growth rate, which is essential for sustainable management of the... -
Otolith shape as a valuable tool to evaluate the stock structure of swordfish Xiphias gladius in the Indian Ocean
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: K Mahé --- Ifremer, Laboratoire Ressources Halieutiques, France H Evano --- Ifremer, Délégation Océan Indien, France T Mille --- Ifremer, Laboratoire Ressources Halieutiques, France D Muths --- Université Européenne de Bretagne, France J Bourjea --- , FranceSwordfish Xiphias gladius is an oceanic-pelagic species. Its population structure in the Western Indian Ocean was studied from the shape of the sagittal otoliths of 391 individuals collected from 2009 to 2014. Normalised elliptical Fourier descriptors (EFDs) were extracted automatically... -
Age and growth of redeye round herring Etrumeus whiteheadi off the South African coast
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: Y Geja --- Branch Fisheries Management, Department of Agriculture, Forestry and Fisheries, South Africa MD Durholtz --- Branch Fisheries Management, Department of Agriculture, Forestry and Fisheries, South Africa CL Moloney --- Zoology Department and Marine Research Institute, South AfricaAges of redeye round herring Etrumeus whiteheadi were estimated with associated errors and used to infer life-history information, such as age composition, age-at-maturity and instantaneous mortality rate. Samples were collected in November 2005 during a research survey aimed at estimating... -
Relationship between somatic growth and otolith growth: a case study of the ornate jobfish Pristipomoides argyrogrammicus from the coast of Réunion (SW Indian Ocean)
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: K Mahé --- Ifremer, Fisheries Laboratory, Sclerochronology Centre, France Y Aumond --- Ifremer, Le Port, France K Rabhi --- Ifremer, Fisheries Laboratory, Sclerochronology Centre, France R Elleboode --- Ifremer, Fisheries Laboratory, Sclerochronology Centre, France E Bellamy --- Ifremer, Laboratoire Environnement Ressources Languedoc Roussillon, France J Huet --- Ifremer, Le Port, France M Gault --- FRS Marine Laboratory, Scotland D Roos --- Ifremer, Le Port, FranceThe ornate jobfish Pristipomoides argyrogrammicus Valenciennes 1832 occurs in the Indo-West Pacific Ocean, where it is harvested by small-scale coastal fisheries. Management of this species is hindered by lack of adequate biological data. We sampled a total of 113 individuals... -
Age and growth of narrow-barred Spanish mackerel Scomberomorus commerson in the coastal waters of southern Mozambique and KwaZulu-Natal, South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: B Lee --- Oceanographic Research Institute (ORI), South Africa BQ Mann --- Oceanographic Research Institute (ORI), South AfricaThe narrow-barred Spanish mackerel Scomberomorus commerson is one of the most important linefish species caught in KwaZulu-Natal and southern Mozambique waters, forming the basis of important commercial, artisanal and recreational fisheries. A total of 439 S. commerson were sampled along... -
The age and growth of hottentot seabream Pachymetopon blochii before and after the South African linefish state of emergency in 2000
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: MW Farthing --- Department of Ichthyology and Fisheries Science, South Africa AC Winkler --- Department of Ichthyology and Fisheries Science, South Africa K Anderson --- Department of Ichthyology and Fisheries Science, South Africa S Kerwath --- Branch: Fisheries Management, Department of Agriculture, Forestry and Fisheries (DAFF), South Africa C Wilke --- Branch: Fisheries Management, Department of Agriculture, Forestry and Fisheries (DAFF), South Africa WM Potts --- Department of Ichthyology and Fisheries Science, South AfricaThe hottentot seabream Pachymetopon blochii is a small-sized (maximum 2.67 kg) sparid endemic to southern Africa. It is an important target in South Africa's Western Cape traditional linefishery, particularly in the absence of more valuable pelagic species (such as Thyrsites... -
Fifty-five-year longevity for the largest member of the family Sparidae: the endemic red steenbras Petrus rupestris from South Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: AH Andrews --- , United States MJ Smale --- , South Africa PD Cowley --- , South Africa N Chang --- , South AfricaA previous study that explored the age and growth of red steenbras Petrus rupestris (Valenciennes, 1830), a large sparid (family Sparidae, seabreams or porgies) endemic to South Africa and reported to approach 2 m in length, provided estimates as a... -
Life-history traits of seabream Boops boops (Linnaeus, 1758) in the central eastern Atlantic Ocean (Canary Islands)
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: A Massaro --- , Italy JG Pajuelo --- , SpainLife-history traits of the sparid Boops boops are studied for the first time in an isolated Atlantic population. Boops boops is a hermaphrodite species characterised by late gonochorism or non-functional hermaphroditism. The 1:0.852 ratio of females to males was significantly... -
Age, growth and natural mortality of blue jack mackerel Trachurus picturatus (Carangidae) from the Canary Islands, Spain (NW Africa)
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: A Jurado-Ruzafa --- , Spain MTG Santamaría --- , SpainStatus assessment of exploited fish populations is a general requirement to ensure sustainability of fisheries in both global and local contexts. The blue jack mackerel Trachurus picturatus (Bowdich, 1825) remains unassessed in a data-limited fishery in the eastern central Atlantic,... -
New age-determination method based on fast growth rate of Cape hake Merluccius capensis in Namibia
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: MR Wilhelm --- Department of Fisheries and Aquatic Science, Namibia SC Paulus --- National Marine Information and Research Centre (NatMIRC), Namibia S Kashava --- National Marine Information and Research Centre (NatMIRC), NamibiaNamibia’s most important commercial fisheries resource, the shallow-water Cape hake Merluccius capensis, is currently assessed using statistical catch-at-age analysis. Age data obtained from otoliths constitute an important data component of this model. Recent age-validation studies of M. capensis showed that... -
Validation of the periodicity of growth zone deposition in otoliths of two large endemic Labeobarbus species in Lake Tana, Ethiopia
Item type: Journal Article • Journal: African Zoology • Authors: Shewit Gebremedhin --- Department of Animal Science and Aquatic Ecology, Belgium Karen Bekaert --- Flanders Research Institute for Agriculture, Fisheries, and Food (ILVO), Belgium Abebe Getahun --- Department of Zoological Sciences, Ethiopia Stijn Bruneel --- Department of Animal Science and Aquatic Ecology, Belgium Wassie Anteneh --- Department of Biology, Ethiopia Els Torreele --- Flanders Research Institute for Agriculture, Fisheries, and Food (ILVO), Belgium Peter Goethals --- Department of Animal Science and Aquatic Ecology, BelgiumAlthough validation of the rate of growth zone deposition is a prerequisite for accurate age estimation, such studies are non-existent for the endemic Labeobarbus species in Lake Tana. Therefore, the aim of the current study was to validate the periodicity... -
A snapshot assessment of the diet of Cape fur seals Arctocephalus pusillus pusillus at Ilha dos Tigres, Angola
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: A Winkler --- Department of Ichthyology and Fisheries Science, South Africa S Mannheim --- Department of Ichthyology and Fisheries Science, South Africa A-R Childs --- Department of Ichthyology and Fisheries Science, South Africa C Santos --- Biologia Faculdade de Ciências, Angola C de Beer --- Department of Ichthyology and Fisheries Science, South Africa MJ Smale --- Department of Zoology and Institute for Coastal and Marine Research, South Africa WM Potts --- Department of Ichthyology and Fisheries Science, South AfricaThe population of Cape fur seal Arctocephalus pusillus pusillus at Ilha dos Tigres off the coast of southern Angola is expanding. Until now the only available biological information on the population has been its demographic parameters, and this insufficiency has... -
Age and growth of Nile tilapia Oreochromis niloticus (Linnaeus, 1758) from Lake Tana, Ethiopia
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: A Degsera --- , Ethiopia M Minwyelet --- , Ethiopia T Yosef --- , EthiopiaAge and growth of Nile tilapia, Oreochromis niloticus, from Lake Tana were studied from June 2016 to May 2017. In total, 1 597 otoliths were collected from three representative sampling sites for macrozone analysis. Otoliths were ground and examined under... -
Stock separation of the shallow-water hake Merluccius capensis in the Benguela ecosystem using otolith shape analysis
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: ENG Shoopala --- , Namibia MR Wilhelm --- , Namibia SC Paulus --- , NamibiaThe fishing industry is an important economic sector in Namibia and South Africa, with the shallow-water hake Merluccius capensis being an important target species. Recent genetic studies of M. capensis found two stocks in the Benguela Current Large Marine Ecosystem,... -
Age and growth of the Cape knifejaw Oplegnathus conwayi, an endemic South African teleost
Item type: Journal Article • Journal: African Zoology • Authors: RM Foster --- , South Africa A-R Childs --- , South Africa BQ Mann --- , South Africa WM Potts --- , South AfricaThe South African spearfishery targets a variety of data-deficient species, which are consequently poorly managed. This study aimed to describe the age and growth of one of these species, the Cape knifejaw, Oplegnathus conwayi, which is endemic to the southern... -
Diet and condition of juvenile deep-water hake Merluccius paradoxus on the west coast of southern Africa
Item type: Journal Article • Journal: African Journal of Marine Science • Authors: E Gammon --- University of Cape Town, South Africa CL Moloney --- University of Cape Town, South Africa MR Lipinski --- Rhodes University, South AfricaThe composition of the diet of juvenile deep-water hake Merluccius paradoxus is described and compared for three body-condition groups (below-average, average, and above-average). Diet was analysed using three metrics: occurrence, numeric and gravimetric. Juvenile hakes were caught in January and... -
Life-history traits in two invasive species of tilapias in Morocco
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: H Ainou --- Mohammed V University, Morocco J Panfili --- IRD, MARBEC (Institut français de recherche pour l'exploitation de la mer, Centre National de la Recherche Scientifique, Institut de Recherche pour le Développement), Université de Montpellier, France A Pariselle --- Mohammed V University, Morocco M Labonne --- IRD, MARBEC (Institut français de recherche pour l'exploitation de la mer, Centre National de la Recherche Scientifique, Institut de Recherche pour le Développement), Université de Montpellier, France H Louizi --- Mohammed V University, Morocco A Benhoussa --- Mohammed V University, Morocco O Berrada Rkhami --- Mohammed V University, Morocco JF Agnèse --- UMR ISEM (Institut de Recherche pour le Développement, Centre National de la Recherche Scientifique, Ecole Pratique de Hautes Etudes), Université de Montpellier, FranceLife-history traits (LHT) of Oreochromis niloticus in the Sidi Mohamed Ben Abdellah reservoir (BA reservoir) and Oreochromis aureus in the Nador Channel were studied and compared with those of other populations in the world. Specimens were collected between June 2018... -
Life-history of invasive common carp, Cyprinus carpio, within a natural lake (Groenvlei), South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: DL Mukhari --- Rhodes University, South Africa L Mofu --- South African Institute for Aquatic Biodiversity (SAIAB), South Africa AT Lombard --- Institute for Coastal and Marine Research, Nelson Mandela University, South Africa CG Attwood --- University of Cape Town, South Africa M Witteveen --- Institute for Coastal and Marine Research, Nelson Mandela University, South Africa MKS Smith --- Rhodes University, South Africa PD Cowley --- Rhodes University, South Africa OLF Weyl --- Rhodes University, South Africa J Pegg --- Rhodes University, South AfricaCommon carp, Cyprinus carpio, is a global invasive species illegally introduced into the Groenvlei system, South Africa, in the 1990s for recreational angling. To manage this population effectively, basic information is needed on its biology including growth and reproduction. This... -
Age and growth of the invasive bluegill Lepomis macrochirus (Rafinesque, 1810) from the Howison’s Poort Dam, Eastern Cape, South Africa
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: PM Ndaleni --- South African Institute for Aquatic Biodiversity, South Africa L Mofu --- South African Institute for Aquatic Biodiversity, South AfricaThe present study assessed the age and growth of bluegill, Lepomis macrochirus (Rafinesque, 1810) from Howison’s Poort Dam, Eastern Cape. Precision between readers and structures (burnt and unburnt) of otoliths were estimated, and the aging error was determined by the...