46 research outputs found
An African heritage of fishes : inaugural lecture delivered at Rhodes University
Inaugural lecture delivered at Rhodes UniversityRhodes University Libraries (Digitisation
Fifty years of ichthyology in Grahamstown
In July 1946, the fledgling Council for Scientific and Industrial Research (CSIR) awarded Dr J.L.B. (James Leonard Brierley) Smith of Rhodes University College a research fellowship of ÂŁ800 to enable him to devote his energies to ichthyology. The university responded by providing accommodation, equipment and appointing Smith a research professor. These actions marked the beginning of what has become a major academic development in Grahamstown as represented by the J.L.B. Smith Institute of Ichthyology, the Department of Ichthyology and Fisheries Science (DIFS), and the Freshwater Fish Section at the Albany Museum. At present more than 40 people are employed in one way or other in these organizations, more than 20 of them professionals, in addition to whom there are 41 postgraduate students currently studying ichthyology or fisheries science through DIFS at Rhodes University. Altogether this represents a concentration of ichthyological expertise probably unmatched anywhere else in the world. It is opportune therefore to highlight a few of the more significant milestones in the history of ichthyology in Grahamstown and so illuminate some of the key factors behind this achievement
Systematics and biogeography of the redfin Barbus species (Pisces : Cyprinidae) from Southern Africa
Resumé: This study deals with the systematics and biogeography of a group of minnowlike Barbus species which, as adults, are characterized by bright red fins. The species are found in the coastal rivers of the fold belt region of the southern and south-western Cape Province. A closely related species, Oreodaimon quathlambae, inhabits certain high altitude streams of the Drakensberg mountains. Traditional methods were employed to revise the taxonomy of the species. Characters studied included morphometric and meristic measurements, and several qualitative anatomical features, several of which were studied in these species for the first time. A new species, Barbus erubescens Skelton, was described during the course of the study (Appendix 3). The taxonomic status of other species are endorsed or revised (B.afer and B.asper). Each species is redescribed and figured. The complete osteology of one redfin species, B.burchelli, is described and illustrated. Comparisons are made with all other redfin species and various osteological characters of systematic value are discussed. The phylogeny of the redfins is studied using Hennigian methods. Comparative data from other southern African Barbus species and pertinent literature were used to determine and evaluate synapomorphic characters and character sequences. The redfins sensu lato are shown to be diphyletic. Barbus calidus Barnard and B.erubescens were found to be sister species not closely related to the other redfin species. Oreodaimon quathlambae (Barnard) is shown to be monophyletic with the second redfin lineage. Barbus burgi Boulenger is placed as the plesiomorph sister species in this lineage and consecutive dichotomies derive Barbus burchelli (Smith); Barbus afer Peters, and Barbus asper Boulenger; Barbus phlegethon Barnard; Barbus tenuis Barnard and Oreodaimon quathlambae. The classification of the redfins is reviewed in the light of their phylogeny and recommendations for an infonnal hierarchy are made. The generic status of each lineage is considered and a new genus, Pseudobarbus, erected for all the redfin species except B.calidus and B.erubescens, but including O. quathlambae. The distributions of redfin species are recorded. A hypothesis is given to explain this distribution, based on a comparison of distribution patterns of a number of plant and animal species and a consideration of the geological and geographical history of southern Africa. Vicariance is suggested to be the major factor which influenced redfin distribution. A theory of dispersal explains the distribution of P.tenuis. The biogeography suggests the redfins are relatively ancient (possibly Miocene?) southern African fishes. Suggestions are made on future studies on the redfins. Attention is drawn to possible implications of the redfin study on systematic study of southern African freshwater fishes
Ichthyological Bulletin of the J.L.B. Smith Institute of Ichthyology; No. 56
A neotype for Clarias gariepinus (Burchell, 1822) is designated and described. Data from 41 specimens from the type locality are also presented. The geographical distribution of the species is discussed.Rhodes University Libraries (Digitisation
Karyology of the redfin minnows, genus Pseudobarbus Smith, 1841 (Teleostei: Cyprinidae): one of the evolutionarily tetraploid lineages of South African barbines
The karyotypes of six species of Pseudobarbus Smith, 1841, namely P. afer (Peters, 1864), P. asper (Boulenger, 1911), P. burchelli Smith, 1841, P. burgi (Boulenger, 1911), P. phlegethon (Barnard, 1938) and P. tenuis (Barnard, 1938), were examined by conventional Giemsa staining and described. All six karyotypes have 2n = 100 chromosomes, dominated by biarmed chromosomes, as does the only other member of the genus, P. quathlambae (Barnard, 1938). Sex-related intraspecific karyotype variation was not found. The shared chromosome numbers and general similarity of the karyotypes (FN = 186–192) provide a new synapomorphy to support their monophyly, which is already indicated by anatomical and mtDNA markers. Karyotype evolution within the genus has been accompanied by chromosomal inversions and centromeric shifts. Comparison of the diploid number found in Pseudobarbus with other African barbine cyprinines, which have in the region of 2n=50 and lower FNs, suggests a tetraploid evolutionary origin of the genus, possibly by allotetraploidy
Ichthyological Bulletin of the J.L.B. Smith Institute of Ichthyology; No. 50
The publication of a new phase of research on the fishes of the Okavango drainage starts with this account which gives the valid names and broad distribution patterns of all species known from the system. Eighty species and subspecies are recognised, of which at least two (Parakneria fortuita Penrith; Serranochromis gracilis Greenwood) are endemic. Notes on early collections, synonymy, taxonomic status and distribution are given. New synonyms are recognized under Aplocheilichthys hutereaui (A. schalleri), Aplocheilichthys johnstoni (Haplochilus carlislei) and Ctenopoma multispinis (Ctenopoma machadoi) respectively. Recently published taxonomic changes are incorporated including two genera (Mesobola and Afromastacembelus), a species Serranochromis (Sargochromis) gracilis and the re-allocated Amphilius uranoscopus. The Zambezian Hemichromis species is re-identified as H. elongatus. A number of unresolved taxonomic problems are pointed out and certain dubious records are excluded from the checklist. The Okavango has a diverse fish fauna with tropical affinities. Many fish species are poorly studied. Man-induced threats to the continued natural functioning of this complex and dynamic system, especially large-scale water abstraction, overgrazing, deforestation and biocide spraying to eliminate tsetse fly, make it imperative that studies on the nature and role of the fishes are continued.Rhodes University Libraries (Digitisation
Reproductive and feeding biology of the Natal mountain catfish, Amphilius natalensis (Siluriformes: Amphiliidae)
The family Amphiliidae comprises nine genera and about 60 species. Only five species are found in southern Africa, three of which belong to the genus Amphilius (Skelton 1993). These soft-bodied catlets inhabit clear, fast flowing mountain streams where they live amongst cobbles, feeding predominantly on benthic invertebrates (Crass 1964, Skelton 1993). The Natal mountain catfish, A. natalensis Boulenger, 1917, is a small, nocturnal species with a restricted distribution along the eastern seaboard of southern Africa. It occurs in mountain streams from the Umkomaas River north to the Limpopo system in South Africa. It is also present in the Marozi River, a tributary of the Zambezi River in Zimbabwe and in the Ruo River, Malawi (Skelton 1984, 1993). Skelton (1993) suggested that predation by introduced trout species has led to scarcity of A. natalensis in many streams. In spite of this, no studies on the biology of this catfish species have been published. This study presents the first quantitative information on the biology of an amphiliid catfish, A. natalensis including gametogenesis, spawning seasonality, size-at-maturity, adult sex ratio and diet
The genetic legacy of lower sea levels : does the confluence of rivers during the last glacial maximum explain the contemporary distribution of a primary freshwater fish (Pseudobarbus burchelli, Cyprinidae) across isolated river systems?
The primary freshwater fish Pseudobarbus
burchelli (Smith 1841) occurs across four presently
isolated river systems in the south-western cape floristic
region of South Africa. Mitochondrial DNA cytochrome
b (701 base pairs) and control region (601 base
pairs) genes were sequenced to assess the evolutionary
history of P. burchelli and evaluate the role of climatic
and landscape changes in shaping patterns of genetic
variation in this species. We identified three historically
isolated lineages in P. burchelli: a widespread lineage
that occurs across three isolated river systems and two
geographically restricted lineages. The results were
evaluated against predictions of the confluence of river
systems during low sea levels of the last glacial
maximum. Occurrence of the widespread Breede
lineage in the Duiwenhoks River system is consistent
with reconstructed palaeoriver systems. However, the
occurrence of this lineage in the Goukou river system
that formed part of the eastern Gourits–Goukou palaeoriver
system can only be explained by translocation or a recent river capture or episodic inundation of low
drainage divides. Extreme ecological gradients or the
potential presence of instream physical barriers could
have prevented an exchange of lineages between the
Breede and Heuningnes river systems.Table Mountain Fund and Prince Bernhard Scholarships, the National Research
Foundation (South Africa) and the Claude Leon Foundation.http://link.springer.com/journal/10750hb201
Biola Hour Highlights, 1974 - 07
If I Were the Devil by Paul Harvey I Pledge Allegiance by Red Skelton Communicating the Gospel by Al Sanders Last Days: Perilous Times by Al Sanders The Revelation of Jesus Christ by Lloyd Anderson Panel Discussions with Richard Chase, Charles Feinberg, and Samuel Sutherlandhttps://digitalcommons.biola.edu/bhhs/1006/thumbnail.jp
Biola Hour Highlights, 1974 - 07
If I Were the Devil by Paul Harvey I Pledge Allegiance by Red Skelton Communicating the Gospel by Al Sanders Last Days: Perilous Times by Al Sanders The Revelation of Jesus Christ by Lloyd Anderson Panel Discussions with Richard Chase, Charles Feinberg, and Samuel Sutherlandhttps://digitalcommons.biola.edu/bhhs/1006/thumbnail.jp