DOCSLIB.ORG

The Barbs of Lake Tana, Ethiopia: Morphological Diversity and Its Implications for Taxonomy, Trophic Resource Partitioning, and Fisheries Promotor: Prof

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Barbs of Lake Tana, Ethiopia: Morphological Diversity and Its Implications for Taxonomy, Trophic Resource Partitioning, and Fisheries Promotor: Prof The barbs of Lake Tana, Ethiopia: morphological diversity and its implications for taxonomy, trophic resource partitioning, and fisheries Promotor: Prof. Dr. J.W.M. Osse Hoogleraar Algemene Dierkunde CO-promotor: Dr. F.A. Sibbing Universitair Hoofddocent Functionele Diermorfologie aan de Ieerstoelgroep Experimentele Dierkunde, departement Dienvetenschappen Leo Nagelkerke The barbs of Lake Tana, Ethiopia: morphological diversity and its implications for taxonomy, trophic resource partitioning, and fisheries Proefschrift ter verkrijging van de graad van doctor op gezag van de rector magnificus van de Landbouwuniversiteit te Wageningen, dr. C.M. Karssen, in het openbaar te verdedigen op dinsdag 7 oktober 1997 des namiddags te half twee in de aula Abstract Nagelkerke, L.A.J. 1997. The barbs of Lake Tana, Ethiopia: morphological diversity and its implications for taxonomy, trophic resource partitioning, and fisheries. Doctoral thesis. Esperimental Animal Morphology and Cell Biology, Wageningen Agricultural University, P.O. Box 338, 6700 AH Wageningen. The Netherlands ISBN: 90-5485-755-2 Subject headings: Barbus 1 biodiversity 1 cyprinids 1 ecomorphology 1 feeding 1 food partitioning 1 lakes l species flock I sustainable fisheries The rediscovery of a unique species flock of cyprinid fish, its taxonomy and its feeding-biology are described. Fourteen species of barbs (Barbus spp, Cyprinidae, Teleostei) were found in highland (1800 m) Lake Tana, in northwestern Ethiopia. Lake Tana is an isolated fresh-water system, because its only outflowing river, the Blue Nile, of which it is the source, drops over 40 m high waterfalls only 35 km from the lake. The carplike barbs in the lake are unique and show a wide variety of discrete, and consistent types, widely differing in 1) size and shape, 2) feeding behaviour, and 3) spatial distribution. Together with 4) the early morphological divergence of juvenile barbs, 5) the reproductive segregation of the adults, and 6) part of their genetic characters, this diversity was decisive in our description of fourteen endemic species. seven of them new to science. Lake Tana was formed by volcanic blocking of the Blue Nile and subsequent flooding of the Lake Tana basin. The Barbus species probably evolved within the lake itself from one common ancestor, very similar to the present-day, riverine B. intermedius, making it a unique species flock. The driving force of their evolution most likely involved radiation into the new lacustrine trophic niches that became available when Lake Tana filled up. The presence of this group of very closely related fishes provides a unique opportunity to study the evolution of adaptation, and the relation of morphology and ecology: it forms a 'natural laboratory'. By using an ecomorphological approach, based on properties of fish foods, and functional morphological studies of the relations between fish parameters and their significance in dealing with food properties. predictions on the diets and food partitioning of the barbs have been made. These predictions were based 011 a large set of characters (33, which made the method robust and allowed for accurate resolving power Testing of the predictions with field data revealed that individual diets, but especially food partitioning can bc well predicted. This new method provides insights into the dynamic trophic interactions among species without the need for an extensive ecological sampling programme, and could be instrumental in predicting shifts in fish fauna composition, due to environmental impact, such as overfishing or thc introduction of ncw species. The understanding and prediction of such shifts will help in developing a strategy towards sustainable fisheries and the protection of biodiversity. This research was supported by: NWO-WOTRO, project number W88-176 Interchurcl~Foundation EthiopiaIEritrea (ISE), Urk Interchurch Coordination Commission for Develop~nent(ICCO), Zeist, Fisheries Resources Development Department of the Ministry of Agriculture, Addis Ababa Bureau of Agriculture of theA~nharaNational Regional State, Bahar Dar Ethiopian Orthodox Church (EOCIDICAD), development department Agricultural University Wageningen Cover: Lake Tana with Great white pelicans (Pelecanus onocuotalus) and Black kitcs (Mi1vzi.s migrans) at Bahar Dar in the rainy season: photograph by G.J.M. van Snik. Cover design: Wim Valen. Caput Nili quaerere ("De bronnen van de Nijl zoeken": een zeer lastig kanvei beginnen) +fifl+CI h9MA flh% +&ss\ ("Langzaam maar zeker zal een ei pootjes krijgen en gaan lopen"; Arnhaars spreekwoord) Vlum en nzijn vuren lach drinkt uii onizaggelijke schnlen van luchi en aarde den opalen dag (H. Marsman, Verzamelde Gedichten, 1938, uitgeverij Querido) Chapter 1 General Introduction 7 Chapter 2 The barbs (Barbus spp.) of Lake Tana: a forgottten species flock? 31 published: L.A.J. Nagelkerke, F.A. Sibbing, J.G.M. van den Boogaart. E.M.R.R. Lammens & J.W.M. Osse (1994). Environtnental Biology ofFishes 39: 1-22. Chapter 3 Morphological divergence during growth in the large barbs 57 (Barbus spp.) of Lake Tana, Ethiopia. published: L.A.J. Nagelkerke, F.A. Sibbing & J.W.M. Osse (1995). Netherlands Journal of Zoology 45: 43 1-454. Chapter 4 Reproductive segregation among the large barbs (Barbus intermedius 79 complex) of Lake Tana, Ethiopia. An example of intralacustrine speciation? published: L.A.J. Nagelkerke & F.A. Sibbing (1996). Journal ofFish Biologv 49: 1244-1266. Chapter 5 A revision of the large barbs (Barbus spp., Cyprinidae, Teleostei) of 105 Lake Tana, Ethiopia, with a description of seven new species. accepted: L.A.J. Nagelkerke & F.A. Sibbing. Zoologische Verhandelingen Leiden. Chapter 6 Trophic segregation within the Barbus species flock of Lake Tana, 171 Ethiopia: 1. Diets predicted from food properties and fish morphology. in preparation: F.A. Sibbing & L.A.J. Nagelkerke. Chapter 7 Trophic segregation among the Barbus species flock of Lake Tana, 229 Ethiopia: 2. Test of diet predictions and food partitioning. in preparation: L.A.J. Nagelkerke & F.A. Sibbing. Chapter 8 In Lake Tana, a unique fish fauna needs protection. published: L.A.J. Nagelkerke, M.V. Mina, T. Wudneh, F.A. Sibbing h J.W.M. Osse (1995). Bioscience 45: 772-775. References Summary / Samenvatting Dankwoord en epiloog Curriculum vitae List of publications Chapter l General introduction Leo A.J. Nagelkerke' ' Agricultural University, Wageningen Institute of Animal Sciences (WIAS), Experimental Zoology Group, Marijkeweg 40, 6709 PG Wageningen, The Netherlanh In 1986, the Lake Tana Fisheries Resources Development Program (LTFRDP) was started by the Ethiopian Ministry of Agriculture, in cooperation with the Development Branch of the Ethiopian Orthodox Church (EOC). The project was supported by the lnterchurch Foundation Ethiopia (ISE) from Urk, The Netherlands. At this time, hardly anything was known about the identity and dynamics of the Lake Tana fish resources. Therefore, Tesfaye Wudneh was assigned as fisheries expert, to investigate the fish stocks. One of the species in the lake, Barh1r.s intermedirrs Riippell showed such an immense morphological variability that it was suspected that there were at last several different populations of barbs in Lake Tana and possibly several species. The presence of different species or populations, and therefore of different units of fish stock complicates rational management of the resources. To investigate the identity and the evolution of the Lake Tana Barbus biodiversity and its role in the ecosystem, a research project was initiated. The results of that study are reported in this thesis. Before I will evaluate the results of the research project, I will first introduce Lake Tana in a broad sense: its topography, climate, flora and fauna in general, and its fish in particular. Secondly I will describe the context and history of my research project, its aims, and its progress in answering the major questions. The latter is, of course, subject of the main body of this thesis and Water- falls Fig.l.1. A map of Ethiopia and Lake Tana. The southern Bahar Dar Gulf is indicated, as well as the Blue Nile and the waterfalls in it. 8 General introduction every chapter will be discussed in short. Finally there will be a short general discussion in which I will try to come to a synthesis of the research until now. This involves addressing some preliminary results that are not presented in the following chapters, and making some generalizations. This also brings me to future research that still should be performed to come to an even better understanding of Lake Tana. Short introduction to Lake Tana Topography and geology Lake Tana is situated in the north-western highlands of Ethiopia in the provinces of Gojjam and Gonder, at an altitude of approximately 1800 m (Fig. l.l). It is the source of the Blue Nile (or Abbay as it is called in Amharic, the chief language of this part of Ethiopia), and as such it has been a place that was searched for since the times of Julius Caesar and Alexander the Great. The first European to see the legendary source was the Portugese Jesuit Pedro Paez, in 16 13. The so-called Tana-rift, in which Lake Tana lies, rs a shallow trough which is not connected to the main Eastern Rift Valley as such, but it certainly has some relation to it (Baker et al. 1972, Mohr 1962). The lake probably formed through volcanic blocking of the Blue Nile in early Pleistocene times (Mohr 1962). Subsequently the Lake Tana basin filled up. It now covers an area of approximately 3 150 km2, and is Ethiopia's largest lake. Four larger, permanent rivers tribute to the lake (the largest is Gelgel Abbay; the 'small Blue Nile", which is c. 100 km), as well as many short, seasonal streams. The lake is shallow with an average depth of 8 m and a maximum depth of 14 m. Its bottom consists of volcanic basalts, usually covered with a muddy substratum with only little organic matter (1.2-2.3%: Gasse 1987). At some places volcanic peaks in the lake bottom form reefs, or even islands (Fig.
Load more

Recommended publications
  • Molecular Investigations of the Diversity of Freshwater Fishes Across Three Continents
    Molecular Investigations of the Diversity of Freshwater Fishes across Three Continents by Malorie M. Hayes A dissertation submitted to the Graduate Faculty of Auburn University in partial fulfillment of the requirements for the Degree of Doctor of Philosophy Auburn, Alabama August 8, 2020 Keywords: Enteromius, Barbus, sub-Saharan Africa, phylogenetics, systematics, Pteronotropis, conservation genetics, Trichomycterus, Guyana Copyright 2020 by Malorie M. Hayes Approved by Jonathan W. Armbruster, Chair, Professor and Director Auburn University Museum of Natural History Department of Biological Sciences Jason E. Bond, Professor and Schlinger Chair in Insect Systematics University of California, Davis Scott R. Santos, Professor and Chair of the Department of Biological Sciences at Auburn University John P. Friel, Director of the Alabama Museum of Natural History Abstract Fishes are the most speciose vertebrates, and incredible diversity can be found within different groups of fish. Due to their physiological limitations, fish are confined to waters, and in freshwater fish, this is restricted to lakes, rivers, and streams. With a constrained habitat like a freshwater system, it can be expected that freshwater fish will show varying levels of diversity depending on a suite of characteristics. Within this dissertation, I examine the diversity of three fish groups: the speciose Enteromius of West Africa, the population genetic diversity of Pteronotropis euryzonus in Alabama and Georgia, and the unexpectedly species rich Trichomycterus from the Guyana highlands. I use molecular methods and geometric morphometrics to determine the systematics of the species and uncover the hidden diversity within their respective groups. When it comes to diversity, the small barbs of Africa are vastly understudied and require a taxonomic revision.
    [Show full text]
  • Xenopus Laevis As Uberxl for Nematodes
    African Zoology ISSN: 1562-7020 (Print) 2224-073X (Online) Journal homepage: https://www.tandfonline.com/loi/tafz20 Xenopus laevis as UberXL for nematodes Anneke L Schoeman, Tracy-Lee Joubert, Louis H du Preez & Roman Svitin To cite this article: Anneke L Schoeman, Tracy-Lee Joubert, Louis H du Preez & Roman Svitin (2020): Xenopuslaevis as UberXL for nematodes, African Zoology, DOI: 10.1080/15627020.2019.1681295 To link to this article: https://doi.org/10.1080/15627020.2019.1681295 View supplementary material Published online: 17 Mar 2020. Submit your article to this journal Article views: 13 View related articles View Crossmark data Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=tafz20 African Zoology 2020, 55(1): xxx–xxx Copyright © Zoological Society Printed in South Africa — All rights reserved of Southern Africa AFRICAN ZOOLOGY This is the final version of the article that is ISSN 1562-7020 EISSN 2224-073X published ahead of the print and online issue https://doi.org/10.1080/15627020.2019.1681295 Xenopus laevis as UberXL for nematodes Anneke L Schoeman1,2* , Tracy-Lee Joubert1, Louis H du Preez1,3 and Roman Svitin1,3,4 1 African Amphibian Conservation Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa 2 Centre of Excellence for Invasion Biology, Department of Botany and Zoology, University of Stellenbosch, Stellenbosch, South Africa 3 South African Institute for Aquatic Biodiversity, Grahamstown, South Africa 4 Department of Invertebrate Fauna and Systematics, II Schmalhausen Institute of Zoology, Kyiv, Ukraine *Corresponding author, email: [email protected] The effect of invasive species on local parasite dynamics is often overlooked.
    [Show full text]
  • Baseline Aquatic Ecology Assessment for Bakubung Platinum Mine
    Prepared by Knight Piésold (Pty) Ltd 4 De La Rey Road Rivonia, Johannesburg South Africa, 2128 Prepared for Bakubung Minerals Proprietary Limited Farm 259, R565, JQ Bultfontein Ledig Rustenburg North West Province RSA Project Number RI 301-00509/14 BASELINE AQUATIC ECOLOGY ASSESSMENT FOR BAKUBUNG PLATINUM MINE Rev Description Date A Issued in Final 03 April 2020 B Specialist Reports and Reports on Specialist Processes - Checklist NEMA Regulations (2014) – Appendix 6 Reference to section in report 1 A specialist report or a report on a specialised process prepared in terms of these Regulations must contain - (a) i The person who prepared the report; and Section (a) ii The expertise of that specialist to compile a specialist Annexure A reports including a curriculum vitae; (b) A declaration that the specialist is independent in a Next page form as may be specified by the competent authority (c) An indication of the scope of, and the purpose for Section 1.4 which the report was prepared (d) Duration, date and season of the site investigation and the relevance of the season to the outcome of the Section 3.2 assessment (e) Description of the methodology adopted in preparing the report or carrying out the specialised process Section 3.0 inclusive of equipment and modelling used (f) The specific identified sensitivity of the site related to the proposed activity or activities and its associated Section 2.1 structures and infrastructure, inclusive of a site plan identifying site alternatives (g) An identification of any areas to be avoided, including
    [Show full text]
  • Biodiversity Impact Assessment
    March 2020 19121900-328397-9 APPENDIX H Biodiversity Impact Assessment REPORT Specialist Assessment for the Proposed Surface Pipeline and Associated Infrastructure - Biodiversity Impact Assessment AngloGold Ashanti (Pty) Limited South African Operations Submitted to: Anglo Gold Ashanti (Pty) Limited South African Operations Mr J van Wyk Carletonville - Fochville Road R500 Carletonville Gauteng 2501 Submitted by: Golder Associates Africa (Pty) Ltd. Building 1, Maxwell Office Park, Magwa Crescent West, Waterfall City, Midrand, 1685, South Africa P.O. Box 6001, Halfway House, 1685 +27 11 254 4800 19121900-327695-6 February 2020 February 2020 19121900-327695-6 Distribution List 1 eCopy to Anglo Gold Ashanti (Pty) Limited South African Operations 1 eCopy to [email protected] i February 2020 19121900-327695-6 Executive Summary Project overview The AGA operations in the West Wits mining lease areas are at risk of flooding due to ingress of fissure water from surrounding mining operations. Approximately 25 Mℓ/day of fissure water flows into the underground workings of the defunct Blyvooruitzicht Mine, which spans a strike of 6 km along the boundary with AGA. If dewatering at the Old Blyvooruitzicht Shafts (#4, #5 & 6#) shafts were to cease, uncontrolled fissure water would report to the AGA operations, which would pose both a flood and safety risk of AGA personnel and the mining operations. This report provides a professional opinion regarding the anticipated terrestrial, wetland and aquatic impacts from this proposed project. Location The proposed water pipeline and associated infrastructure is located approximately 80 km west of Johannesburg. It originates at CWC 4#, approximately 3.3 km south east of Carletonville and ends at the North Boundary Dam (NBD) approximately 6 km south-south-west of Carletonville in Blyvooruitzicht, Merafong City Local Municipality, West Rand District Municipality in the Gauteng Province of South Africa.
    [Show full text]
  • Barbus Sensitivus, a New Species with Extensive Pitlines from the Sanaga River (Teleostei: Cyprinidae)
    aqua, International Journal of Ichthyology Barbus sensitivus, a new species with extensive pitlines from the Sanaga River (Teleostei: Cyprinidae) Tyson R. Roberts Research Associate, Smithsonian Tropical Research Institute. Email: [email protected] Received: 29 June 2010 – Accepted: 10 August 2010 Abstract vergleichende Studien unter Einbeziehung von REM- Barbus sensitivus new species, from the Sanaga River in Bildern, die Vergleich und Bestimmung ermöglichen. Keine Cameroon, West Africa, has a much more slender caudal der bisher beschriebenen Arten ähnelt dieser neuen Art peduncle than any other small African barb. It also has besonders. Die pitline organelles von B. sensitivus n. sp. extensively distributed exposed pitline organelles in pit lines haben freiliegende oder freie Neuromasten. Ihre Funktion- on the head and scales, illustrated here by scanning electron sweise ist vermutlich mechanosensorisch. Bei der erwachse- micrographs. Similar pit lines and pitline organelles evi- nen B. sensitivus n. sp. sind sie in großen Grubenreihen auf dently occur in various other Old World barbs assigned to Kopf und Rumpf extensiv verteilt; sie ähneln Seitenlinien- various genera in Africa and Asia but adequate comparative Neuromasten bei weit entwickelten Larven von Cyprinus car- studies including SEM observations are not available to pio, Gnathopogon elongatus caerulescens und Danio rerio. permit their comparison and identification. None of the Hauptsächlich sind die Neuromasten auf den ventrolateralen species previously described are very similar to this new Teil des Kopfes konzentriert, wo ihre Zahl rund 30.000 species. The pitline organelles of B. sensitivus n. sp. have beträgt, jeweils mit 20 bis 100 Kinozilien (Flimmerhärchen) exposed or free neuromasts. Their sensory modality pre- mit einer Länge von 7 Mikrometern und 0,4 Mikrometern sumably is mechanosensory.
    [Show full text]
  • Reply to Yang Et Al. 2015
    See discussions, stats, and author profiles for this publication at: http://www.researchgate.net/publication/278047497 Nomenclatural changes should not be based on equivocally supported phylogenies: Reply to Yang et al. 2015 ARTICLE in MOLECULAR PHYLOGENETICS AND EVOLUTION · JUNE 2015 Impact Factor: 3.92 · DOI: 10.1016/j.ympev.2015.05.025 · Source: PubMed READS 88 2 AUTHORS: Ray C. Schmidt Henry Bart Smithsonian Tropical Research Institute Tulane University 7 PUBLICATIONS 1 CITATION 56 PUBLICATIONS 613 CITATIONS SEE PROFILE SEE PROFILE All in-text references underlined in blue are linked to publications on ResearchGate, Available from: Ray C. Schmidt letting you access and read them immediately. Retrieved on: 29 October 2015 Molecular Phylogenetics and Evolution 90 (2015) 193–194 Contents lists available at ScienceDirect Molecular Phylogenetics and Evolution journal homepage: www.elsevier.com/locate/ympev Letter to the Editor Nomenclatural changes should not be based on equivocally supported phylogenies: Reply to Yang et al. 2015 q ⇑ Ray C. Schmidt , Henry L. Bart Jr. Department of Ecology and Evolutionary Biology, Tulane University, 400 Boggs Hall, New Orleans, LA 70118, United States Tulane University Biodiversity Research Institute, Belle Chasse, LA 70037, United States article info abstract Article history: Phylogenies produced by Yang et al. 2015 provide reasonably well-supported hypotheses of relationships Received 22 May 2015 among 11 proposed tribes of cyprinine fishes and present an interesting hypothesis about the origin of a Accepted 31 May 2015 number of polyploid cyprinine lineages. However, support for relationships within some of the tribes is Available online 6 June 2015 equivocal. Herein we address the treatment of African diploid and tetraploid cyprinine genera within tribe Smiliogastrini.
    [Show full text]
  • Environmental Impact Assessment for the Musina- Makhado Special Economic Zone, Limpopo Province
    Environmental Impact Assessment for the Musina- Makhado Special Economic Zone, Limpopo Province Freshwater Impact Report Project Number: LEA5522 Prepared for: Limpopo Economic Development Agency September 2019 _______________________________________________________________________________________ Digby Wells and Associates (South Africa) (Pty) Ltd Co. Reg. No. 2010/008577/07. Turnberry Office Park, 48 Grosvenor Road, Bryanston, 2191. Private Bag X10046, Randburg, 2125, South Africa Tel: +27 11 789 9495, Fax: +27 11 069 6801, [email protected], www.digbywells.com _______________________________________________________________________________________ Directors: GE Trusler (C.E.O), LF Koeslag, J Leaver (Chairman)*, NA Mehlomakulu*, DJ Otto *Non-Executive _______________________________________________________________________________________ This document has been prepared by Digby Wells Environmental. Report Type: Freshwater Impact Report Environmental Impact Assessment for the Musina- Project Name: Makhado Special Economic Zone, Limpopo Province Project Code: LEA5522 Name Responsibility Signature Date Field surveyor and Kathryn Roy report compiler April 2019 (Wetlands) Field surveyor, Kieren Bremner report compiler and May 2019 Pr.Sci.Nat. review (Aquatics & Wetlands) Byron Bester Peer review May 2019 Pr.Sci.Nat. This report is provided solely for the purposes set out in it and may not, in whole or in part, be used for any other purpose without Digby Wells Environmental prior written consent. Digby Wells Environmental i Freshwater Impact
    [Show full text]
  • Morphometry and DNA Barcoding Reveal Cryptic Diversity in the Genus Enteromius (Cypriniformes: Cyprinidae) from the Congo Basin, Africa
    European Journal of Taxonomy 310: 1–32 ISSN 2118-9773 https://doi.org/10.5852/ejt.2017.310 www.europeanjournaloftaxonomy.eu 2017 · Van Ginneken M. et al. This work is licensed under a Creative Commons Attribution 3.0 License. Research article urn:lsid:zoobank.org:pub:E07A58BA-7D3B-4231-9C77-97A031128E62 Morphometry and DNA barcoding reveal cryptic diversity in the genus Enteromius (Cypriniformes: Cyprinidae) from the Congo basin, Africa Marjolein VAN GINNEKEN 1,†, Eva DECRU 2,*,†, Erik VERHEYEN 3 & Jos SNOEKS 4 1 Department of Biology, Systemic Physiological and Ecotoxicological Research, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium. 2,4 Royal Museum for Central Africa, Section Vertebrates, Ichthyology, Leuvensesteenweg 13, 3080 Tervuren, Belgium. 2,4 Department of Biology, Laboratory of Biodiversity and Evolutionary Genomics, KU Leuven, Charles Deberiotstraat 32, 3000 Leuven, Belgium. 3 Royal Belgian Institute of Natural Sciences, OD Taxonomy and Phylogeny, Vautierstraat 29, 1000 Brussels, Belgium; Department of Biology, Evolutionary Ecology Group, University of Antwerpen, Campus Drie Eiken, building D, room D.150 Universiteitsplein 1, 2610 Antwerpen, Belgium. † Equally contributing authors * Corresponding author: [email protected] 1 Email: [email protected] 3 Email: [email protected] 4 Email: [email protected] 1 urn:lsid:zoobank.org:author:FDADB435-8B18-49C9-B803-F925ABF21A22 2 urn:lsid:zoobank.org:author:1AEB7EED-C939-4702-8590-B3FCA7076324 3 urn:lsid:zoobank.org:author:86B40463-E3D9-4147-9ED3-D7302E0D64B6 4 urn:lsid:zoobank.org:author:13A8AB26-FF46-437C-9806-D49E11C5E15D Abstract. One of the main challenges to adequately conserve the African fi sh fauna is to improve our so far unsatisfactory taxonomic knowledge of important portions of the ichthyofauna.
    [Show full text]
  • Ecology and Potential for Fishery of the Small Barbs (Cyprinidae, Teleostei) of Lake Tana, Ethiopia
    Promotoren: prof. dr. Jan W.M. Osse, hoogleraar in de algemene dierkunde, co-promotor: dr. Ferdinand A. Sibbing, universitair hoofddocent bij de leerstoelgroep Experimentele Zo¨ologie, dr. Jacobus Vijverberg, senior onderzoeker bij het NIOO-KNAW Centrum voor Limnologie, Nieuwersluis, overige leden promotiecommissie: prof. dr. Paul Skelton, JLB Smith Institute of Ichthyology, South Africa, prof. dr. Marten Scheffer, Wageningen Universiteit, dr. Leo A.J. Nagelkerke, Wageningen Universiteit, dr. Seyoum Mengistu, Addis Ababa University, Ethiopia, dr. Jan H. Wanink, Universiteit Leiden. ECOLOGY AND POTENTIAL FOR FISHERY OF THE SMALL BARBS (CYPRINIDAE, TELEOSTEI) OF LAKE TANA, ETHIOPIA Eshete Dejen Dresilign Proefschrift ter verkrijging van de graad van doctor op gezag van de rector magnificus van Wageningen Universiteit, prof. dr. ir. L. Speelman, in het openbaar te verdedigen op dinsdag 2 september 2003 des namiddags te vier uur in de Aula. Dejen Dresilign, E. (2003). The small barbs of Lake Tana. Doctoral thesis, Experimental Zoology Group, Wageningen University, P.O. Box 338, 6700 AH Wageningen, The Netherlands. Subject headings: small Barbus / taxonomy / ecology / zooplankton / zooplanktivorous / fishery / Lake Tana, Ethiopia ISBN: 90-5808-869-3 To Neter Alemu (my mother) and Dejen Dresilign (my father) vi Contents 1 Introduction 1 1.1 General introduction .................................... 1 1.1.1 Importance of small pelagics for fisheries ..................... 1 1.1.2 Zooplankton and zooplanktivorous fish in the food web of tropical waterbodies 2 1.1.3 Lake Tana and its environment .......................... 3 1.1.4 Lake Tana and its fish community ........................ 4 1.1.5 Initiation and objectives of the research ..................... 6 1.1.6 Sampling Programme ............................... 8 1.2 Introduction to the various chapters ..........................
    [Show full text]
  • A Little Fish with a High Heavy Metals Burden
    ntal & A me na n ly o t ir ic Ngesa et al., J Environ Anal Toxicol 2018, 8:4 v a n l T E o Journal of f DOI: 10.4172/2161-0525.1000583 x o i l c o a n l o r g u y o J Environmental & Analytical Toxicology ISSN: 2161-0525 ResearchResearch Article Article OpenOpen Access Access A Little Fish with a High Heavy Metals Burden: The Case of Straightfin Barb, Enteromius paludinosus (Peters 1852) from River Malewa, Naivasha, Kenya Elizabeth Adhiambo Ngesa, Elick Onyango Otachi* and Nzula Kivuva Kitaka Department of Biological Sciences, Egerton University, PO Box 536, Egerton, Kenya Abstract This paper addresses the accumulation of heavy metals namely; Arsenic (As), Chromium (Cr), Lead (Pb) and Mercury (Hg) in the tissues of Straightfin barb, Enteromius paludinosus (Peters 1852) from the mouth of River Malewa in Lake Naivasha, Kenya. A total of 1307 fish were collected from the lake during the month of November, 2017. Water samples, sediment samples, 25 fish muscle tissues and its endoparasite, the cestode Ligula intestinalis were collected and heavy metal concentrations determined using the Thermal-electron atomic absorption spectrophotometer. The concentrations of these heavy metals in the sediment showed no signs of pollution. In the muscle tissues of the fish, As, Cr, Pb and Hg showed high levels with mean concentrations of 5.0696, 22.0854, 45.2108 and 1.5458 mg/ kg ww respectively. The Target hazard quotients of As, Cr, Pb and Hg obtained were 98.5066, 42.9138, 65.8863 and 90.1086 respectively, indicating a possible health risk associated with the consumption of the straightfin barb.
    [Show full text]
  • Geographic Distribution and Identification of Pathways Of
    GEOGRAPHIC DISTRIBUTION AND IDENTIFICATION OF PATHWAYS OF INTERACTIONS OF TILAPIINE SPECIES BETWEEN NATURAL AND AQUACULTURE SYSTEMS IN UPPER TANA RIVER BASIN, KENYA By Otieno Kashim Oginga (BSc. Environmental science, Kenyatta University, 2016) Thesis submitted in Partial Fulfillment of the Requirements for the award of the Degree of Master of Arts in Biodiversity and Natural Resources Management, Department of Geography and Environmental Studies, University of Nairobi. October 2020 DECLARATION This thesis is my original work, and has not been presented for award of any degree in any other university. Where other people’s work has been used, this has been properly acknowledged and referenced in accordance with the University of Nairobi’s regulations. Otieno Kashim Oginga Sign: Date: 20/11/2020 C50/10191/2018 - Department of Geography and Environmental Studies University of Nairobi Supervisors Prof. Francis Mwaura Sign: Date: 20./11/2020 Department of Geography and Environmental Studies University of Nairobi Prof. Nathan Gichuki Sign: Date: 20/11 / 2020 School Biological Sciences, University of Nairobi Dr. Wanja Dorothy Nyingi Sign: Date: 20/11/2020 Ichthyology Section, National Museums of Kenya Prof. George Turner Sign: Date: 21/11/2020 School of Natural Sciences, Bangor University, UK ii DEDICATION This work is dedicated my parents, Thomas Oginga and Pamela Akinyi for their continuous advise and encouragement since the beginning of my education and my son Thomas Hensley Otieno for inspiration. iii ACKNOWLEDGEMENT I would like to express my gratitude to God for his eternal guidance in my life. My sincere thanks to my supervisors: Prof. Francis Mwaura, Prof. Nathan Gichuki, Dr. Wanja Nyingi and Prof.
    [Show full text]
  • UNIVERSITY of CALIFORNIA SANTA CRUZ Biodiversity, Biogeography
    UNIVERSITY OF CALIFORNIA SANTA CRUZ Biodiversity, Biogeography, and Conservation of Freshwater Fishes in Gabon A dissertation submitted in partial satisfaction of the requirements for the degree of DOCTOR OF PHILOSOPHY in ECOLOGY AND EVOLUTIONARY BIOLOGY By Joseph S. Cutler September 2019 The Dissertation of Joseph S. Cutler is approved: ______________________________ Dr. Don Croll, Chair ______________________________ Dr. Giacomo Bernardi ______________________________ Dr. Eric Palkovacs ______________________________ Dr. Brian Sidlauskas ______________________________ Dr. Bernie Tershy ______________________________ Quentin Williams Acting Vice Provost and Dean of Graduate Studies Table of Contents List of Figures iv Abstract vi Acknowledgements vii Introduction 1 Chapter 1 6 Chapter 2 49 Chapter 3 130 Chapter 4 147 Conclusion 162 Bibliography 166 iii List of Figures Chapter 1 1.1. Figure 1.1…………………………………………………………………... 11 1.2. Figure 1.2…………………………………………………………………... 12 1.3. Figure 1.3……………………………………………………………………15 1.4. Figure 1.4……………………………………………………………........... 16 1.5. Figure 1.5…………………………………………………………………... 16 1.6. Figure 1.6…………………………………………………………………... 20 1.7. Figure 1.7…………………………………………………………………... 21 1.8. Figure 1.8…………………………………………………………………... 23 1.9. Figure 1.9…………………………………………………………………... 25 1.10. Figure 1.10…………………………………………………………………. 27 1.11. Figure 1.11…………………………………………………………………. 32 1.12. Figure 1.12…………………………………………………………………. 34 1.13. Figure 1.13…………………………………………………………………. 36 1.14. Figure 1.14…………………………………………………………………. 40 Chapter 2 2.1. Figure 2.1…………………………………………………………………... 52 2.2. Figure 2.2…………………………………………………………………... 55 2.3. Figure 2.3……………………………………………………………………57 2.4. Table 2.2……………………………………………………………..……...58 iv 2.5. Figure 2.4……………………………………………………………………63 2.6. Figure 2.5……………………………………………………………………71 2.7. Figure 2.6……………………………………………………………………79 2.8. Figure 2.7……………………………………………………………………83 2.9. Figure 2.8……………………………………………………………………92 2.10. Figure 2.9……………………………………………………………………94 2.11.
    [Show full text]