Coastal fishes of the western Indian Ocean
- Authors: Heemstra, Phillip C. 1941- , Heemstra, Elaine , Ebert, Dave , Holleman, Wouter , Randall, John E
- Date: 2022
- Subjects: Marine fishes Indian Ocean , Marine fishes Indian Ocean Identification
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/310495 , vital:59157 , ISBN 978-1-990951-23-7 , ISBN 978-1-998950-35-5 , ISBN 978-1-990951-28-2
- Description: The primary purpose of this book is to provide a means of identifying the more than 3 200 species of coastal fishes known to occur in the Western Indian Ocean (WIO). Coastal fishes are those that inhabit waters generally less than ~200 m deep, the waters over continental and insular shelves, and upper continental slopes. The book also includes some oceanic species and species that live in deeper water, but are sometimes caught in trawls in less than 200 m, or that migrate into shallower waters at night to feed. The Western Indian Ocean (WIO), as treated in these volumes, is the area between Cape Point, South Africa, and 77°34' E, at Kanyakumari (formerly Cape Cormorin), the southernmost point of India, and to 40° S, just south of St Paul Island. Although considered as separate water bodies, the Red Sea and Persian/Arabian Gulf have been included. Some contributors have also chosen to include species from Sri Lanka. The region thus encompasses the entire east and southern coasts of Africa, Madagascar and the various island clusters of the Comoros, the Seychelles, the Maldive and Lakshadweep islands, the Chagos Archipelago and the islands and sea mounts of the Mascarene Plateau, to as far as 40° S, and thus some fishes from St Paul and Amsterdam Islands have been included. This large expanse, stretching from tropical waters of the northwestern Indian Ocean to the warm temperate waters of False Bay, South Africa, includes a number of poorly known biogeographic areas. A map of the entire Indian Ocean is placed on the inside front cover of each printed volume, with some areas in greater detail on the inside back cover. The book does not include distribution maps for species, but gives localities from which species are known, with emphasis on WIO localities; our understanding of distributions of many species is often incomplete. Fishes are the most abundant and diverse group of vertebrates and have colonised every aquatic habitat on Earth: the oceans, lakes, rivers and caves, from polar seas at –2 °C to hot, freshwater springs at 44 °C, and from tropical reefs and mangrove forests to the deepest ocean depths. Fishes are also the most poorly known group of vertebrates. In the 2006 edition of Joseph Nelson’s Fishes of the World the estimate of the number of species of extant fishes worldwide stood at about 23 000. This number is growing annually, and was thought to be about 33 460 species at the end of 2016 (www.fishwisepro.com). Between the years 2000 and 2015 an average of 150 new species of marine fishes were described each year – of which 10% of the total (156 species) were from the WIO. The WIO is home to about 15% of all the marine fish species in the world’s oceans. Another measure of the diversity of fishes of this area is its relatively high level of endemicity, particularly around southern Africa and in the Red Sea. About 13% of southern African marine fishes are endemic, most of these in only five families: Clinidae with about 44 endemic species, Gobiidae with 28, Sparidae with 28, Pentanchidae with 6, and Batrachoididae with 7 endemic species. In the Red Sea at least 170 of the more than 1100 species are endemic. The WIO region is also home to a large human population, representing a wide range of ethnic and cultural backgrounds. The area includes the countries of South Africa, Mozambique, Tanzania, Kenya, Somalia, Eritrea, Sudan, Egypt, Israel, Jordan, Saudi Arabia, Yemen, Oman, United Arab Emirates, Qatar, Bahrain, Kuwait, Iraq, Iran, Pakistan, India and Sri Lanka, as well as the many island nations and territories. Many of the people living in coastal areas are dependent on fish catches and other marine resources for both sustenance and often a livelihood, as highly diversified artisanal fisheries make up the bulk of the fishing effort in the region. And, as elsewhere in the world, many of the fish resources have been compromised by commercial interests (including those of other countries), often leaving fish stocks in a poor state. This book has a number of purposes, all of which coalesce around providing users with a better understanding of the area’s fishes and their environment. Accordingly, it includes a number of background chapters covering subjects as diverse as the oceanography of the region, and the history and evolution of the bony fishes. In recent years genetic analysis has proved to be a powerful tool for taxonomists. In many instances molecular results have caused taxonomists to rethink both the definitions of certain taxa and the interrelationships of taxa. In some instances, what were long considered cohesive (monophyletic) taxa were found to include groups of fishes that are in fact not closely related (paraphyletic), while in other instances taxa thought to be distinct were found not to be, meriting their merging with other existing taxa. At times, long-accepted family groups have been divided into two or more distinct families, or separate families have been combined into a single one. Where possible such changes in our understanding of the relationships of fishes are reflected in these volumes. Where some contributors have taken a more conservative approach by awaiting more research and not adopting these changes, alternative taxonomies are noted (see also the introductory chapter on Naming organisms and determining their relationships). For each species in the book, the literature pertinent to that species in the WIO is given: the original species description reference, synonyms for the region and other important taxonomic and biological references. For many commercially important species or fishes of interest to anglers there is additional information on life history, size and capture, and for some but not all species, their IUCN conservation status if Near Threatened, Vulnerable, Endangered or Critically Endangered (in the first instance, valid at the time of writing. See www.iucnredlist.org for current information. Note: we have not included the IUCN conservation status where species are of Least Concern or Data Deficient). Most species are illustrated with photographs, drawings or paintings. Colour photographs and paintings are provided on plates for each volume. , 1st Edition
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- Date Issued: 2022
Contrasting signals of genetic diversity and historical demography between two recently diverged marine and estuarine fish species
- Authors: von Der Heyden, Sophie , Toms, Jessica A , Teske, Peter R , Lamberth, Stephen J , Holleman, Wouter
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445611 , vital:74407 , https://doi.org/10.3354/meps11191
- Description: Estuaries, at the confluence of marine and freshwater systems, are mostly of geologically recent origin and as such make excellent models for understanding recent speciation events. Using molecular approaches, we compared genetic diversity and demographic histories in 2 closely related southern African klipfish species, the marine Clinus superciliosus and the estuarine C. spatulatus. Strong genetic differentiation was identified using both mtDNA control region and nDNA S7 sequencing, despite some haplotype sharing. Coalescent-based modelling suggests that species divergence occurred during the Late Pleistocene or, more likely, during the Early Holocene, when present-day estuaries formed. Analyses of population demography suggest that C. superciliosus has undergone historical population expansion, whereas C. spatulatus is characterized by a population decline, potentially driven by repeated cycles of population crashes linked to the opening and closing of estuarine systems. This is also reflected in values of genetic diversity, which are almost an order of magnitude lower in the estuarine than in the marine species. Given the unique evolutionary history of C. spatulatus, a species that is restricted to only 2 South African estuaries, we highlight the need for a better understanding of the processes that have shaped the evolution of estuarine populations. The identification of unique genetic lineages in estuaries can help to better guide conservation and management efforts for some of South Africa’s most fragile habitats.
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- Date Issued: 2015
The taxonomy and osteology of fishes of the family Tripterygiidae (Perciformes : Blennioidei) of South Africa
- Authors: Holleman, Wouter
- Date: 1979
- Subjects: Tripterygiidae -- South Africa , Blennioidei -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5185 , http://hdl.handle.net/10962/d1001961 , Tripterygiidae -- South Africa , Blennioidei -- South Africa
- Description: This study is divided into two parts. The first deals with the taxonomy of the South African fishes of the Tripterygiidae. The second part describes the osteology of one genus of the family, and draws comparisons with the other genera discussed in this study. Five genera of Tripterygiidae are recognized from South African waters. Cremnochorites, a monotypic genus, is described as new. The single species, C. capensis, has been recorded only from the southern and south-eastern coast of South Africa. It is distinguished from other genera by a combination of features which includes scalation, dorsal and anal fin spine counts, and various osteological characters. Three genera, Norfolkia Fowler, Helcogramma McCulloch & Waite, and Enneapterygius Rüppell occur throughout most of the Indo-Pacific. A single species of Norfolkia, N. springeri Clark (in press) is found in Zululand. Two species are ascribed to Helcogramma, H. obtusirostre (Klunzinger) and H. fuscopinna sp.n. Parallels are drawn between two species of Tripterygion Risso, T. tripteronotus and T. delaisi from the Mediterranean. The two South African Helcogramma species show similar depth preferences to the two Tripterygion species, resulting in similar morphological differences between the two species of each pair. The genus Enneapterygius Rüppell is divided into two genera, Enneanterygius and Scoliosolen gen.n. The division is based on the form of the supraoccipital sensory canal and associated osteological characters. Sooliosolen has a crescent-shaped supraoccipital canal and cranial osteology similar to the majority of other tripterygiid genera, whereas Enneapterygius has a 'U'-shaped supraoccipital canal which curves around the first dorsal fin, a comparatively long, concave supraoccipital bone which extends anteriorly between the parietal and between the posterior ends of the frontals. Two species are referred to Scoliosolen, S. abeli (Klausewitz) and S. conspicuus (Clark), and two new species are described for Enneapterygius, E. pulcherrimus and E. trianeulus. A literature survey revealed little consistency in ascribing species to any particular genus. Thus, throughout this study an attempt is made to define the genera so that future confusion can be avoided. In the light of these definitions an assessment is made of the original descriptions of a large number of species to determine which of the species can be ascribed to Norfolkia and to Helcogramrna. This has been possible to a lesser degree for Enneapterygius and Scoliosolen, for the major external feature separating these two genera, the shape of the supraoccipital sensory canal, is described only for Red Sea (Clark, in press) and South African species (this study). This study places four species in Enneapterygius, and six in Scoliosolen. To provide a firmer foundation for defining the genera, an investigation was made of the osteology of Scoliosolen conspicuus. Enneapterygius was originally chosen for the osteolofical study as it is reputedly the largest genus of the family, and thus likely to be the most generalized. Once comparisons had been made with other Enneapterygius species, it became apparent that this genus had to be divided into two genera, Enneapterygius and Scoliosolen. It is not known whether Scoliosolen is the largest genus, but it is likely to be one of the largest once a complete survey of the species originally ascribed to Enneapterygius has been undertaken. Finally, an osteological comparison is made of the five genera which occur in South African waters to provide firmer bases for the generic definitions. Only those characters which appear to be constant within a genus are used. Reference is made to a number of genera which do not occur in South African waters, to ensure that the characters chosen cannot be applied to other genera
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- Date Issued: 1979