DOCSLIB.ORG

Fisheries and Cichlid Evolution in the African Great Lakes: Progress and Problems

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Fisheries and Cichlid Evolution in the African Great Lakes: Progress and Problems 131 Article Fisheries and cichlid evolution in the African Great Lakes: progress and problems Rosemary Lowe-McConnell St George’s Park, Burgess Hill, Sussex RH15 0SG, UK. Email: [email protected] Received 22 May 2009; accepted 25 September 2009; published 16 November 2009 Abstract This paper updates Recent Advances in the African Great Lakes: Fisheries, Biodiversity and Cichlid Evolution published by the Freshwater Biological Association in Freshwater Forum (Lowe- McConnell, 2003). Since 2003 many international teams have continued research on lakes Malawi, Victoria and Tanganyika. This review discusses the decline of the important commercial fisheries in all three lakes, together with changes in ecological and limnological conditions which the fishes now face. It also describes advances in our understanding of how the spectacular flocks of endemic cichlid species have evolved in each lake and continue to coexist. Keywords: African lakes; cichlid evolution; cichlid ecology; fisheries; Lake Victoria; Lake Malawi; Lake Tanganyika. Introduction obtain funds for projects on lakes Malawi, Tanganyika and Victoria. These lakes were all facing serious threats The East African Great Lakes have long been renowned for caused by the rapid rise in human populations, with fisheries of vital importance for the rapidly rising riparian associated over-fishing, sedimentation, and pollution from human populations and as biodiversity hotspots with changes in land use in the lake basins. Since the early 1990s spectacular endemic faunas. The flocks of cichlid fishes research involving over a hundred scientists, financed unique to each of the three largest lakes, Victoria (69 000 by many international bodies, has produced numerous km2) and the long deep rift-valley lakes, Tanganyika and publications in widely-scattered journals. In 2003, the Malawi (previously Nyasa) (Fig. 1), have offered unique Freshwater Biological Association published a Special opportunities to investigate how new species evolve and Issue of Freshwater Forum on Recent Advances in the African coexist (as discussed by Lowe-McConnell, 1993, 1996). Great Lakes: Fisheries, Biodiversity and Cichlid Evolution In 1989, an International Symposium on ‘Resource Use (Lowe-McConnell, 2003). This synopsis summarised the and Conservation of the African Great Lakes’ was held at status of the fisheries and the then current ideas on how Bujumbura on Lake Tanganyika, followed by numerous the rich endemic fish faunas had evolved. It also described workshops at other venues. Further international interest the biodiversity surveys made in each lake based on in biodiversity, generated at the Rio Earth Summit in 1992, underwater (SCUBA) observations of fish ecology and then enabled the United Nations and other agencies to behaviour, followed by cichlid breeding experiments in DOI: 10.1608/FRJ-2.2.2 Freshwater Reviews (2009) 2, pp. 131-151 © Freshwater Biological Association 2009 132 Lowe-McConnell, R. Fig. 1. The East African Great Lakes: Lake Victoria drains via Lake Kyoga and Lake Albert to the Nile, Lake Tanganyika to the Congo system (Zaire) and Lake Malawi to the Zambezi River. Figure originally from Lowe-McConnell, R. 1996. Fish communities in the African Great Lakes. Environmental Biology of Fishes, 45: 219-235. Reproduced with kind permission of Springer Science and Business Media. aquaria and DNA techniques in many laboratories to test ideas on the evolution, origins and relationships of the Fisheries cichlid species. New publications since 2003 have further advanced our understanding of how the spectacular Lake Malawi fisheries flocks of cichlid species have evolved and coexist in lakes Victoria and Malawi, but the main commercial fisheries Sixty years ago the first fishery survey of Lake Nyasa (now of these lakes, so needed to feed the rapidly rising human L. Malawi) showed that the main commercial fisheries populations, have declined. The present review describes were supported by cichlid tilapia caught in shore seines the most outstanding contributions on both these topics and open water ring nets (Bertram et al., 1942). Since published from 2003 to 2009. then, however, tilapia abundances have declined and the © Freshwater Biological Association 2009 DOI: 10.1608/FRJ-2.2.2 Fisheries and cichlid evolution in the African Great Lakes 133 species of endemic tilapia are now so scarce that the main could adversely affect Malawi’s endemic fishes, as it did commercial fishery (Maldeco, which works in association when introduced into Madagascar (Reinthal et al., 2003). with the Malawi Fishery Department) has resorted to Research into environmental conditions affecting fish breeding tilapia in fish-farm ponds to stock large enclosures production in Lake Malawi has included, for example, fixed in open waters in the south east arm of the lake. the work by Duponchelle et al. (2005) on food partitioning Here they rear endemic tilapia (Oreochromis shiranus and within the species-rich benthic fish community. Using a ‘chambo’ O. karongae) but the endemic, more open-water- combination of stable isotopes and stomach analyses, they dwelling O. lidole, once so abundant in ring net catches, has found that, although benthic algal production contributed been over fished to such an extent that it has now vanished to the energy requirements of offshore fishes living in and is ‘probably extinct’ (Turner, personal communication). water 10 m to 30 m deep, the larvae of the abundant lake Maldeco, which produces 70 % of Malawi’s total fish catch, fly Chaoborus edulis were the most important food source no longer targets tilapia (the most popular fish) which was for demersal fishes, thus supporting the hypothesis reported in 2005 to be at the ‘lowest point ever’. Artisanal that demersal fish production in L. Malawi is sustained fisheries for cichlids and other fishes continue elsewhere on mainly through the pelagic food chain, rather than from this 600 km long lake, from which total catches are reported benthic detritus. Isotopic differences among species by the Malawi Fisheries Department to fluctuate between with apparently similar diets, feeding behaviour and 26 000 and 47 000 tonnes annually. To augment the fish depth preferences, suggested that important resource supplies Maldeco uses three bottom trawlers which catch partitioning does exist among L. Malawi’s benthic mainly very numerous small haplochromine cichlid species, haplochromine cichlids. A Special Issue of the Journal of including ndunduma Diplotaxodon of several species, Great Lakes Research on The African Great Lakes (eds Bootsma discovered during the UK/SADC Pelagic Zone survey in et al., 2003), has an introductory paper by Bootsma & 1995. Small cichlid species now contribute between 60 % Hecky (2003) comparing the biology and limnology of and 70 % of Maldeco’s annual catch, of which 90 % is sold the African Great Lakes. Twelve of the other very diverse fresh (frozen); Maldeco also has a fish processing plant and papers were based on data from L. Malawi. These, in smoke kiln for fillets of any large fish they catch, especially addition to discussing seasonal and spatial patterns of catfishBagrus meridionalis. To help meet the country’s large experimental trawl catches (Deponchelle et al., 2003) demand for fish, they have acquired another landing site at and the return to local fisheries management (Dobson & Salima on the main lake, for which a fourth fishing vessel is Lynch, 2003), included other observations by numerous on order (Press Corporation Ltd, 2009). authors on meteorology, nutrient upwelling, sources Fish from smaller lakes in Malawi, and from pond and fluxes of organic carbon, silica cycling, community culture, also contribute to the country’s total catch. The composition, distribution and nutrient status of epilithic WorldFish Centre, based in the Philippines, has assisted periphyton in the rocky littoral, environmental factors Malawian farmers to grow tilapia in rain-fed ponds for controlling the distributions of benthic invertebrates on which new varieties of tilapia are being selected for fast rocky shores, and nitrogen and phosphorus regeneration growth. Commendably, Malawi does not stock exotic fish, by cichlids in the littoral zone. In a paper on the impact which can so easily escape to the detriment of indigenous of land use on sediments and nutrients, Hecky et al. species. The very vigorous Nile tilapia (O. niloticus), (2003) showed that changes in land use in the L. Malawi cultivated in many ponds worldwide, when introduced into basin, with its rapidly increasing human population and Lake Victoria ousted the endemic tilapia (as described later). associated agricultural development and forest clearance, This aggressive species has now spread in southern Africa, probably increased nutrient loading to the lake by 50 %. including Lake Kariba from where it has replaced Zambezi Responses to nutrient-enrichment experiments tilapias (Tweddle, 2007). This very dominant tilapia species (with P, N and Fe) demonstrated that, in adequate light, DOI: 10.1608/FRJ-2.2.2 Freshwater Reviews (2009) 2, pp. 131-151 134 Lowe-McConnell, R. phytoplankton quickly become nutrient-deficient. O. niloticus thrived despite the presence of this predatory Enrichment experiments with and without zooplankton centropomid (now Latidae) that was introduced into the (> 50 µm) by Guildford et al. (2003) in Lake Malawi Ugandan waters of the lake in the mid 1950s as a ‘sport’ fish (during three seasons – stratified rainy, deep mixing and and to crop the numerous
Load more

Recommended publications
  • Fish, Various Invertebrates
    Zambezi Basin Wetlands Volume II : Chapters 7 - 11 - Contents i Back to links page CONTENTS VOLUME II Technical Reviews Page CHAPTER 7 : FRESHWATER FISHES .............................. 393 7.1 Introduction .................................................................... 393 7.2 The origin and zoogeography of Zambezian fishes ....... 393 7.3 Ichthyological regions of the Zambezi .......................... 404 7.4 Threats to biodiversity ................................................... 416 7.5 Wetlands of special interest .......................................... 432 7.6 Conservation and future directions ............................... 440 7.7 References ..................................................................... 443 TABLE 7.2: The fishes of the Zambezi River system .............. 449 APPENDIX 7.1 : Zambezi Delta Survey .................................. 461 CHAPTER 8 : FRESHWATER MOLLUSCS ................... 487 8.1 Introduction ................................................................. 487 8.2 Literature review ......................................................... 488 8.3 The Zambezi River basin ............................................ 489 8.4 The Molluscan fauna .................................................. 491 8.5 Biogeography ............................................................... 508 8.6 Biomphalaria, Bulinis and Schistosomiasis ................ 515 8.7 Conservation ................................................................ 516 8.8 Further investigations .................................................
    [Show full text]
  • View/Download
    CICHLIFORMES: Cichlidae (part 3) · 1 The ETYFish Project © Christopher Scharpf and Kenneth J. Lazara COMMENTS: v. 6.0 - 30 April 2021 Order CICHLIFORMES (part 3 of 8) Family CICHLIDAE Cichlids (part 3 of 7) Subfamily Pseudocrenilabrinae African Cichlids (Haplochromis through Konia) Haplochromis Hilgendorf 1888 haplo-, simple, proposed as a subgenus of Chromis with unnotched teeth (i.e., flattened and obliquely truncated teeth of H. obliquidens); Chromis, a name dating to Aristotle, possibly derived from chroemo (to neigh), referring to a drum (Sciaenidae) and its ability to make noise, later expanded to embrace cichlids, damselfishes, dottybacks and wrasses (all perch-like fishes once thought to be related), then beginning to be used in the names of African cichlid genera following Chromis (now Oreochromis) mossambicus Peters 1852 Haplochromis acidens Greenwood 1967 acies, sharp edge or point; dens, teeth, referring to its sharp, needle-like teeth Haplochromis adolphifrederici (Boulenger 1914) in honor explorer Adolf Friederich (1873-1969), Duke of Mecklenburg, leader of the Deutsche Zentral-Afrika Expedition (1907-1908), during which type was collected Haplochromis aelocephalus Greenwood 1959 aiolos, shifting, changing, variable; cephalus, head, referring to wide range of variation in head shape Haplochromis aeneocolor Greenwood 1973 aeneus, brazen, referring to “brassy appearance” or coloration of adult males, a possible double entendre (per Erwin Schraml) referring to both “dull bronze” color exhibited by some specimens and to what
    [Show full text]
  • View/Download
    CICHLIFORMES: Cichlidae (part 5) · 1 The ETYFish Project © Christopher Scharpf and Kenneth J. Lazara COMMENTS: v. 10.0 - 11 May 2021 Order CICHLIFORMES (part 5 of 8) Family CICHLIDAE Cichlids (part 5 of 7) Subfamily Pseudocrenilabrinae African Cichlids (Palaeoplex through Yssichromis) Palaeoplex Schedel, Kupriyanov, Katongo & Schliewen 2020 palaeoplex, a key concept in geoecodynamics representing the total genomic variation of a given species in a given landscape, the analysis of which theoretically allows for the reconstruction of that species’ history; since the distribution of P. palimpsest is tied to an ancient landscape (upper Congo River drainage, Zambia), the name refers to its potential to elucidate the complex landscape evolution of that region via its palaeoplex Palaeoplex palimpsest Schedel, Kupriyanov, Katongo & Schliewen 2020 named for how its palaeoplex (see genus) is like a palimpsest (a parchment manuscript page, common in medieval times that has been overwritten after layers of old handwritten letters had been scraped off, in which the old letters are often still visible), revealing how changes in its landscape and/or ecological conditions affected gene flow and left genetic signatures by overwriting the genome several times, whereas remnants of more ancient genomic signatures still persist in the background; this has led to contrasting hypotheses regarding this cichlid’s phylogenetic position Pallidochromis Turner 1994 pallidus, pale, referring to pale coloration of all specimens observed at the time; chromis, a name
    [Show full text]
  • Out of Lake Tanganyika: Endemic Lake Fishes Inhabit Rapids of the Lukuga River
    355 Ichthyol. Explor. Freshwaters, Vol. 22, No. 4, pp. 355-376, 5 figs., 3 tabs., December 2011 © 2011 by Verlag Dr. Friedrich Pfeil, München, Germany – ISSN 0936-9902 Out of Lake Tanganyika: endemic lake fishes inhabit rapids of the Lukuga River Sven O. Kullander* and Tyson R. Roberts** The Lukuga River is a large permanent river intermittently serving as the only effluent of Lake Tanganyika. For at least the first one hundred km its water is almost pure lake water. Seventy-seven species of fish were collected from six localities along the Lukuga River. Species of cichlids, cyprinids, and clupeids otherwise known only from Lake Tanganyika were identified from rapids in the Lukuga River at Niemba, 100 km from the lake, whereas downstream localities represent a Congo River fish fauna. Cichlid species from Niemba include special- ized algal browsers that also occur in the lake (Simochromis babaulti, S. diagramma) and one invertebrate picker representing a new species of a genus (Tanganicodus) otherwise only known from the lake. Other fish species from Niemba include an abundant species of clupeid, Stolothrissa tanganicae, otherwise only known from Lake Tangan- yika that has a pelagic mode of life in the lake. These species demonstrate that their adaptations are not neces- sarily dependent upon the lake habitat. Other endemic taxa occurring at Niemba are known to frequent vegetat- ed shore habitats or river mouths similar to the conditions at the entrance of the Lukuga, viz. Chelaethiops minutus (Cyprinidae), Lates mariae (Latidae), Mastacembelus cunningtoni (Mastacembelidae), Astatotilapia burtoni, Ctenochromis horei, Telmatochromis dhonti, and Tylochromis polylepis (Cichlidae). The Lukuga frequently did not serve as an ef- fluent due to weed masses and sand bars building up at the exit, and low water levels of Lake Tanganyika.
    [Show full text]
  • The Fish Fauna of Lake Victoria During a Century of Human Induced Perturbations
    The Fish Fauna of Lake Victoria during a Century of Human Induced Perturbations Frans Witte1,2, Mary A. Kishe-Machumu1,3, Olivia C. Mkumbo4, Jan H. Wanink1,5, Pleun C. Goudswaard1,6, Jacco C. Van Rijssel1,2,7, Martien J.P. van Oijen2 ABSTRACT WITTE, F., KISHE-MACHUMU, M. A., MKUMBO, O. C., WANINK, J. H., GOUDSWAARD, P. C., VAN RIJSSEL, J.C. & VAN OIJEN, M. J.P. The fish fauna of Lake Victoria during a century of human induced perturbations. In J. Snoeks & A. Getahun (eds), Pro- ceedings of the Fourth International Conference on African Fish and Fisheries, Addis Ababa, Ethiopia, 22-26 September 2008. Tervuren: Royal Museum for Central Africa, ‘Zoological Documentation Online Series’, pp. 49-66. Lake Victoria, by area the largest tropical lake of the world, is well-known for its diverse native fish fauna, which com- prised about 500 endemic haplochromine cichlid species, two tilapiine species and 46 other species belonging to 12 fami- lies. During the past decades, the fish species diversity in the lake has declined dramatically due to human induced per- turbations in the ecosystem. Based on literature and our own research findings we provide an overview of these changes and their most likely causes. During the first half of the last century, the increasing fishing pressure had a great impact on the native tilapiine cichlids and other large fish species. The shift in fish landings showed a classic example of fishing down the food web. Because of the dwindling catches, the Nile perch and four exotic tilapiine cichlids were introduced into the lake in the 1950s.
    [Show full text]
  • Inventaire Rapide Des Zones Humides Représentatives En République Démocratique Du Congo
    Inventaire Rapide des Zones Humides Représentatives en République Démocratique du Congo Editors and Major Contributors : Michele Thieme, Aurelie Shapiro, Alejandra Colom, Uli Schliewen, Nikolai Sindorf, Andre Kamdem Toham Supported by the Swiss Grant for Africa, Ramsar Convention Secretariat Table of Contents Executive Summary I. Introduction II. Approach and Methodology for Rapid Inventory of Wetland Priority Areas A. Aquatic Ecosystem Classification and Gap Analysis B. Human Use / Suitability Analysis C. Marxan Model D. Delineation and Prioritization of Wetland Areas E. Threats assessment, socio economic importance and key stakeholders Appendix I. Contributors Appendix II. List of Protected Areas used in the Gap Analysis Appendix III. Photos of Wetland Areas Appendix IV. List of Fish Species by Wetland Priority Area Executive Summary In 2002, the government of the Democratic Republic of Congo committed to increase its protected area coverage to 15% from just over 8%. WWF, RAMSAR, OSFAC and other partners supported the effort by convening an expert workshop in Kinshasa, DRC in November 2007, to undertake a country wide biodiversity assessment, including a rapid inventory and prioritization of the biodiversity value of the wetlands of the Democratic Republic of Congo. Several products were developed prior to the workshop to facilitate the work of the experts. These were: (1) a map classifying small sub‐basins in DRC by the predominant aquatic habitat types and (2) a map of human use/suitability. The aquatic habitat or ecosystem map was used as a basis for ensuring representation of all habitat types across the country and the suitability map provided a measure of the level of human impact.
    [Show full text]
  • Ancient Hybridization Fuels Rapid Cichlid Fish Adaptive Radiations
    ARTICLE Received 14 May 2016 | Accepted 20 Dec 2016 | Published 10 Feb 2017 DOI: 10.1038/ncomms14363 OPEN Ancient hybridization fuels rapid cichlid fish adaptive radiations Joana I. Meier1,2,3, David A. Marques1,2,3, Salome Mwaiko1,2, Catherine E. Wagner1,2,4, Laurent Excoffier3,5 & Ole Seehausen1,2 Understanding why some evolutionary lineages generate exceptionally high species diversity is an important goal in evolutionary biology. Haplochromine cichlid fishes of Africa’s Lake Victoria region encompass 4700 diverse species that all evolved in the last 150,000 years. How this ‘Lake Victoria Region Superflock’ could evolve on such rapid timescales is an enduring question. Here, we demonstrate that hybridization between two divergent lineages facilitated this process by providing genetic variation that subsequently became recombined and sorted into many new species. Notably, the hybridization event generated exceptional allelic variation at an opsin gene known to be involved in adaptation and speciation. More generally, differentiation between new species is accentuated around variants that were fixed differences between the parental lineages, and that now appear in many new combinations in the radiation species. We conclude that hybridization between divergent lineages, when coincident with ecological opportunity, may facilitate rapid and extensive adaptive radiation. 1 Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, 3012 Bern, Switzerland. 2 Department of Fish Ecology and Evolution, Centre for Ecology, Evolution & Biogeochemistry, Eawag: Swiss Federal Institute of Aquatic Science and Technology, 6047 Kastanienbaum, Switzerland. 3 Computational and Molecular Population Genetics Lab, Institute of Ecology and Evolution, University of Bern, 3012 Bern, Switzerland. 4 Biodiversity Institute & Department of Botany, University of Wyoming, Laramie Wyoming 82071, USA.
    [Show full text]
  • Sixth International Conference of the Pan African Fish and Fisheries
    SIXTH INTERNATIONAL CONFERENCE OF THE PAN AFRICAN FISH AND FISHERIES ASSOCIATION (PAFFA6) BOOK OF ABSTRACTS Sun N Sand Holiday Resort in Mangochi, Malawi 24th to 28th September 2018. “African Fish and Fisheries: Diversity, Conservation and Sustainable Management” About This Booklet This publication includes abstracts for oral presentations and poster presentations at the Sixth International Conference of The Pan African Fish And Fisheries Association (PAFFA6) held at Sun ‘n’ Sand Holiday Resort in Mangochi, Malawi from 24-28 September, 2018. Section One: Oral Presentations Oral presentations are grouped by conference theme. Please refer to the Conference Programme for details about date, time slot and location for each thematic session. Section Two: Poster Presentations Poster presentations are grouped by conference theme. Please refer to the Conference Programme for details about date, time slot, and location for group poster sessions. All presentations are subject to change after the printing of this publication. The 2018 PAFFA book of abstracts is sponsored by the Fisheries Integration of Society and Habitats Project (FISH) which is made possible by the generous support of the American people through the United States Agency for International Development (USAID) and implemented by Pact. "The contents, are the sole responsibility of LUANAR, Conference Organisers and Delegates and do not necessarily reflect the views of the FISH Project team and partners, USAID, or the United States Government (USG). 1 | P a g e “African Fish and Fisheries: Diversity, Conservation and Sustainable Management” KEY NOTE PRESENTATIONS – PLENARY SESSIONS (NYANJA HALL) Day 1, Monday, 24th September, 2018 Rapid Radiation of the Cichlids of Lake Malaŵi Jay R.
    [Show full text]
  • Supplemental Material
    Supplementary Information The coincidence of ecological opportunity with hybridization explains rapid adaptive radiation in Lake Mweru cichlids Meier et al. Supplementary Figures and Tables Supplementary Figure 1: Lake depth does not explain the lack of speciation in Lake Bangweulu and the presence of multiple adaptive radiations in Lake Mweru Supplementary Figure 2: The interacting radiations of Lake Mweru. Supplementary Figure 3: Comparison of nuclear (left) and mitochondrial trees (right) reveal considerable evidence for monophyly, yet rampant cytonuclear discordance. Supplementary Figure 4: Morphological and genomic PCA of radiations in Lake Mweru. Supplementary Figure 5: Size distribution of the different clades in Lake Mweru. Supplementary Figure 6: Dated mitochondrial phylogeny suggests a recent and broadly overlapping age of the four radiations in Lake Mweru. Supplementary Figure 7: Phylogenetic tree and ADMIXTURE analysis of the serranochromine samples. Supplementary Figure 8: fineRADstructure coancestry matrix of “orthochromines” reveals absence of recent gene flow between Pseudocrenilabrus and Orthochromis species and supports homogenous genomic compositions of the Pseudocrenilabrus radiation. Supplementary Figure 9: fineRADstructure coancestry matrix of serranochromines reveals homogenous patterns of haplotype sharing within each radiation and except for one putative case of backcrossing, shows no evidence for recent gene flow. Supplementary Table 1: Mitochondrial chronogram calibration sets and age estimates. Supplementary Notes Supplementary Note 1: Background on Lakes Mweru and Bangweulu Supplementary Note 2: Taxonomic diversity Supplementary Note 3: Species diversity in the Lake Mweru radiations Pseudocrenilabrus radiation Supplementary Note 4: Comparison of Lake Mweru haplochromines to those of Lake Victoria Supplementary Note 5: Evidence for hybrid origins of the adaptive radiations in Lake Mweru Supplementary References 1 Supplementary Figures and Tables Supplementary Fig.
    [Show full text]
  • Haplochromis Hozvesi Spec, Nov., a Crab and Fish Eating Cichlid from Lake Victoria
    Haplochromis hozvesi spec, nov., a crab and fish eating cichlid from Lake Victoria M.J.P. van Oijen Oijen, M J.P. van. Haplochromis howesi spec, nov., a crab and fish eating cichlid from Lake Victoria. Zool. Med. Leiden 66 (40), 31.xii.1992:561-579, figs 1-28, tables 1-4.— ISSN 0024-0672. Key words: Cichlidae; crab eater; piscivore; Lake Victoria; Haplochromis', new species; fin squamation. A new, crab and fish eating Haplochromis species, with a piscivorous fades, occurring in rocky habitats in Lake Victoria is described. Special attention is given to the squama tion of the dorsal and anal fin membranes. Food preferences of juveniles and adults are discussed, and the decline of this species, in a habitat in which piscivorous Nile perches do not occur, is analysed. M.J.P. van Oijen, Nationaal Natuurhistorisch Museum (Rijksmuseum van Natuurlijke Historie), Postbus 9517,2300 RA Leiden, The Netherlands. Contents Introduction , 561 Methods and techniques 562 Abbreviations 562 Description of Haplochromis howesi spec. nov. 562 Notes on the fin squama tion of Haplochromis howesi , 570 Notes on the food of Haplochromis howesi , 572 Relations between cichlids and crabs in other African lakes 574 Remarks on the decline of Haplochromis howesi 574 Acknowledgements 575 References , 575 Introduction The diversity of the haplochromine community of rocky habitats in Lake Victoria has been discovered only recently. In Greenwood's revision papers only one species, viz. H. nigricans Boulenger, 1906, is associated with rocky habitats (Greenwood, 1956). Van Oijen et al. (1981) and Witte-Maas & Witte (1985) mentioned 16 species collected near the rocks.
    [Show full text]
  • Biostor-80351.Pdf
    - f JUN i Phylogenetic versus convergent relationship USftARY between piscivorous cichlid fishes from Lakes Malawi and Tanganyika Melanie L. J. Stiassny Department of Morphology, Zoological Laboratory, University of Leiden, The Netherlands'. Contents Synopsis 67 Introduction 67 Methods, nomenclature and materials . 68 Methods 68 Nomenclature 69 Materials 70 Abbreviations used in text figures . 70 Anatomical description 73 Ethmovomerine region of the neurocranium 73 Cephalic muscles 77 Pharyngeal jaw apparatus .... 87 Discussion . 98 Acknowledgements 99 References 100 Synopsis The anatomy and phylogenetic relationships of two genera of African cichlid fishes, Rhamphochromis from Lake Malawi and Bathybates from Lake Tanganyika, are investigated. In accordance with the current methods of cladistic analysis data from representatives of a wide range of cichlid taxa are included for outgroup comparison. Particular emphasis is placed upon the anatomy of the ethmovo- merine region of the neurocranium, the cheek musculature, and the pharyngeal jaw apparatus. Based upon a number of synapomorphic characters an hypothesis of a sistergrbup relationship between the monophyletic genus, Bathybates, and a monophyletic assemblage consisting of the genera Hemibates and Trematocara is formulated. A similar resolution of the relationships of Rhampho- chromis has not been achieved; the differential success of the study is discussed and additional data relevant to unravelling the status and relationships of Rhamphochromis are introduced. Introduction The similarities that exist between individual species and whole communities of cichlid fishes in Lakes Malawi and Tanganyika have often been remarked upon (eg. Pellegrin, 1903; Regan, 1921, 1922; Fryer, 1959; Fryer & lies, 1972; Galis & Barel, 1980). Regan (1921) felt that the majority of the Malawian genera were phyletically distinct from any found else- where and that they formed a 'natural group'.
    [Show full text]
  • Recent Research in the African Great Lakes: Fisheries, Biodiversity and Cichlid Evolution
    Recent research in the African Great Lakes: fisheries, biodiversity and cichlid evolution Item Type article Authors Lowe-McConnell, Rosemary Download date 30/09/2021 23:17:08 Link to Item http://hdl.handle.net/1834/22270 4 RO LOWE-MCCONNELL RECENT RESEARCH IN THE AFRICAN GREAT LAKES: FISHERIES, BIODIVERSITY AND CICHLID EVOLUTION ROSEMARY LOWE-McCONNELL Dr R. H. Lowe-McConnell, Streatwick, Streat Near Hassocks, Sussex BN6 8RT, UK Abstract The East African Great Lakes are now well known for (1) their fisheries, of vital importance for their rapidly rising riparian human populations, and (2) as biodiversity hotspots with spectacular endemic faunas, of which the flocks of cichlid fishes unique to each of the three largest lakes, Tanganyika, Malawi and Victoria, offer unique opportunities to investigate how new species evolve and coexist. Since the early 1990s research involving over a hundred scientists, financed by many international bodies, has produced numerous reports and publications in widely scattered journals. This article summarizes their main discoveries and examines the status of, and prospects for, the fisheries, as well as current ideas on how their rich endemic fish faunas have evolved. It first considers fisheries projects in each of the three lakes: the deep rift valley lakes Tanganyika and Malawi and the huge Victoria, all of which share their waters between several East African countries. Secondly it considers the biodiversity surveys of each lake, based on underwater (SCUBA) observations of fish ecology and behaviour which
    [Show full text]