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Mutizwa TI, Kadye WT, Bragança PHN, Bere T, Chakona A. Hidden in the riffles: A new suckermouth catfish (Mochokidae, Chiloglanis) from the middle Zambezi River system, Zimbabwe. Zookeys 2024; 1197:57-91. [PMID: 38616924 PMCID: PMC11015093 DOI: 10.3897/zookeys.1197.114679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 01/22/2024] [Indexed: 04/16/2024] Open
Abstract
The recent surge in the discovery of hidden diversity within rheophilic taxa, particularly in West and East Africa, prompted a closer examination of the extent to which the current taxonomy may obscure the diversity of riffle-dwelling suckermouth catfishes in the genus Chiloglanis in southern Africa. Currently, the region comprises eight valid species within this genus. Seven of them have relatively narrow geographic distribution ranges except for C.neumanni, which is considered to be widely distributed, occurring from the Buzi River system in the south, and its northern limit being the eastward draining river systems in Tanzania. Recent surveys of the middle Zambezi River system revealed Chiloglanis specimens that were distinguishable from the known species of the genus from southern Africa. Integration of molecular and morphological data indicated that these specimens from the Mukwadzi River represent a new species to science, herein described as Chiloglaniscarnatus Mutizwa, Bragança & Chakona, sp. nov. This species is readily distinguished from its southern African congeners by the possession of a distinctive extended dermal tissue covering the base of the dorsal fin and the possession of ten mandibular teeth (vs 8, 12, or 14 in the other taxa). Results from this study add to the growing evidence of a high level of undocumented diversity within riffle-dwelling taxa in southern Africa.
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Affiliation(s)
- Tadiwa I. Mutizwa
- Department of Ichthyology and Fisheries Science, Faculty of Science, Rhodes University, Prince Alfred Street, PO Box 94, Makhanda, 6140, South AfricaNRF-South African Institute for Aquatic BiodiversityMakhandaSouth Africa
- NRF-South African Institute for Aquatic Biodiversity, Somerset Street, Private Bag 1015, Makhanda, 6140, South AfricaRhodes UniversityMakhandaSouth Africa
| | - Wilbert T. Kadye
- Department of Ichthyology and Fisheries Science, Faculty of Science, Rhodes University, Prince Alfred Street, PO Box 94, Makhanda, 6140, South AfricaNRF-South African Institute for Aquatic BiodiversityMakhandaSouth Africa
- NRF-South African Institute for Aquatic Biodiversity, Somerset Street, Private Bag 1015, Makhanda, 6140, South AfricaRhodes UniversityMakhandaSouth Africa
| | - Pedro H. N. Bragança
- NRF-South African Institute for Aquatic Biodiversity, Somerset Street, Private Bag 1015, Makhanda, 6140, South AfricaRhodes UniversityMakhandaSouth Africa
- Department of Ichthyology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USADepartment of Ichthyology, American Museum of Natural HistoryNew YorkUnited States of America
| | - Taurai Bere
- School of Wildlife, Ecology and Conservation, Chinhoyi University of Technology, Private Bag 7724, Chinhoyi, ZimbabweChinhoyi University of TechnologyChinhoyiZimbabwe
| | - Albert Chakona
- Department of Ichthyology and Fisheries Science, Faculty of Science, Rhodes University, Prince Alfred Street, PO Box 94, Makhanda, 6140, South AfricaNRF-South African Institute for Aquatic BiodiversityMakhandaSouth Africa
- NRF-South African Institute for Aquatic Biodiversity, Somerset Street, Private Bag 1015, Makhanda, 6140, South AfricaRhodes UniversityMakhandaSouth Africa
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Day JJ, Steell EM, Vigliotta TR, Withey LA, Bills R, Friel JP, Genner MJ, Stiassny MLJ. Exceptional levels of species discovery ameliorate inferences of the biogeography and diversification of an Afrotropical catfish family. Mol Phylogenet Evol 2023; 182:107754. [PMID: 36906193 DOI: 10.1016/j.ympev.2023.107754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 02/24/2023] [Accepted: 03/05/2023] [Indexed: 03/13/2023]
Abstract
Endeavours in species discovery, particularly the characterisation of cryptic species, have been greatly aided by the application of DNA molecular sequence data to phylogenetic reconstruction and inference of evolutionary and biogeographic processes. However, the extent of cryptic and undescribed diversity remains unclear in tropical freshwaters, where biodiversity is declining at alarming rates. To investigate how data on previously undiscovered biodiversity impacts inferences of biogeography and diversification dynamics, we generated a densely sampled species-level family tree of Afrotropical Mochokidae catfishes (220 valid species) that was ca. 70 % complete. This was achieved through extensive continental sampling specifically targeting the genus Chiloglanis a specialist of the relatively unexplored fast-flowing lotic habitat. Applying multiple species-delimitation methods, we report exceptional levels of species discovery for a vertebrate genus, conservatively delimiting a staggering ca. 50 putative new Chiloglanis species, resulting in a near 80 % increase in species richness for the genus. Biogeographic reconstructions of the family identified the Congo Basin as a critical region in the generation of mochokid diversity, and further revealed complex scenarios for the build-up of continental assemblages of the two most species rich mochokid genera, Synodontis and Chiloglanis. While Syndontis showed most divergence events within freshwater ecoregions consistent with largely in situ diversification, Chiloglanis showed much less aggregation of freshwater ecoregions, suggesting dispersal as a key diversification process in this older group. Despite the significant increase in mochokid diversity identified here, diversification rates were best supported by a constant rate model consistent with patterns in many other tropical continental radiations. While our findings highlight fast-flowing lotic freshwaters as potential hotspots for undescribed and cryptic species diversity, a third of all freshwater fishes are currently threatened with extinction, signifying an urgent need to increase exploration of tropical freshwaters to better characterise and conserve its biodiversity.
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Affiliation(s)
- Julia J Day
- Department of Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK.
| | - Elizabeth M Steell
- Department of Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK
| | - Thomas R Vigliotta
- Department of Ichthyology, American Museum of Natural History, New York, NY, USA
| | - Lewis A Withey
- Department of Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK
| | - Roger Bills
- South African Institute for Aquatic Biodiversity, Private Bag, 1015, 6140 Grahamstown, South Africa
| | - John P Friel
- Alabama Museum of Natural History, The University of Alabama, Box 870340, 35487-0340 Tuscaloosa, AL, USA
| | - Martin J Genner
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Melanie L J Stiassny
- Department of Ichthyology, American Museum of Natural History, New York, NY, USA
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Schedel FDB, Chakona A, Sidlauskas BL, Popoola MO, Usimesa Wingi N, Neumann D, Vreven EJWMN, Schliewen UK. New phylogenetic insights into the African catfish families Mochokidae and Austroglanididae. JOURNAL OF FISH BIOLOGY 2022; 100:1171-1186. [PMID: 35184288 PMCID: PMC9310817 DOI: 10.1111/jfb.15014] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 01/20/2022] [Accepted: 02/16/2022] [Indexed: 06/14/2023]
Abstract
Several hundred catfish species (order: Siluriformes) belonging to 11 families inhabit Africa, of which at least six families are endemic to the continent. Although four of those families are well-known to belong to the 'Big-Africa clade', no previous study has addressed the phylogenetic placement of the endemic African catfish family Austroglanididae in a comprehensive framework with molecular data. Furthermore, interrelationships within the 'Big-Africa clade', including the most diverse family Mochokidae, remain unclear. This study was therefore designed to help reconstruct inter- and intrarelationships of all currently valid mochokid genera, to infer their position within the 'Big Africa clade' and to establish a first molecular phylogenetic hypothesis of the relationships of the enigmatic Austroglanididae within the Siluriformes. We assembled a comprehensive mitogenomic dataset comprising all protein coding genes and representing almost all recognized catfish families (N = 33 of 39) with carefully selected species (N = 239). We recovered the monophyly of the previously identified multifamily clades 'Big Asia' and 'Big Africa' and determined Austroglanididae to be closely related to Pangasiidae, Ictaluroidea and Ariidae. Mochokidae was recovered as the sister group to a clade encompassing Auchenoglanididae, Claroteidae, Malapteruridae and the African Schilbeidae, albeit with low statistical support. The two mochokid subfamilies Mochokinae and Chiloglanidinae as well as the chiloglanid tribe Atopochilini were recovered as reciprocally monophyletic. The genus Acanthocleithron forms the sister group of all remaining Mochokinae, although with low support. The genus Atopodontus is the sister group of all remaining Atopochilini. In contrast to morphological reconstructions, the monophyly of the genus Chiloglanis was strongly supported in our analysis, with Chiloglanis macropterus nested within a Chiloglanis sublineage encompassing only other taxa from the Congo drainage. This is an important result because the phylogenetic relationships of C. macropterus have been controversial in the past, and because we and other researchers assumed that this species would be resolved as sister to most or all other members of Chiloglanis. The apparent paraphyly of Synodontis with respect to Microsynodontis provided an additional surprise, with Synodontis punu turning out to be the sister group of the latter genus.
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Affiliation(s)
- Frederic D. B. Schedel
- Zoological InstituteUniversity of BaselBaselSwitzerland
- Department of IchthyologySNSB‐Bavarian State Collection of ZoologyMunichGermany
- Faculty of BiologyLMU MunichMunichGermany
| | | | - Brian L. Sidlauskas
- Department of Fisheries, Wildlife and Conservation SciencesOregon State UniversityCorvallisOregonUSA
| | | | | | - Dirk Neumann
- Department of IchthyologySNSB‐Bavarian State Collection of ZoologyMunichGermany
| | - Emmanuel J. W. M. N. Vreven
- Vertebrate Section, Royal Museum for Central AfricaTervurenBelgium
- KU Leuven, Laboratory of Biodiversity and Evolutionary GenomicsLeuvenBelgium
| | - Ulrich K. Schliewen
- Department of IchthyologySNSB‐Bavarian State Collection of ZoologyMunichGermany
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Chakona A, Jordaan MS, Raimondo DC, Bills RI, Skelton PH, van der Colff D. Diversity, distribution and extinction risk of native freshwater fishes of South Africa. JOURNAL OF FISH BIOLOGY 2022; 100:1044-1061. [PMID: 35170047 DOI: 10.1111/jfb.15011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/08/2021] [Accepted: 02/13/2022] [Indexed: 06/14/2023]
Abstract
Extinction risk for 101 valid species and 18 unique genetic lineages of native freshwater fishes of South Africa was assessed in 2016 following the IUCN Red List criteria. An additional five species (three new species that were described and two species that were revalidated subsequent to the 2016 assessments) were assessed in the present study. A synthesis of the outcome of the assessments of the 106 valid species and 18 genetic lineages indicates that 45 (36%) of South Africa's freshwater fish taxa are threatened (7 Critically Endangered, 25 Endangered, 13 Vulnerable). Of the remaining taxa, 17 (14%) are listed as Near Threatened, 57 (46%) are Least Concern and five (4%) are Data Deficient. More than 60% of the endemic taxa are threatened. The Cape Fold Ecoregion has the highest proportion of threatened taxa (67%) due to the existence of a unique assemblage of narrow-range endemic species. Galaxias and Pseudobarbus have the highest number of highly threatened taxa as most of the species and lineages in these genera are classified as either CR or EN. Major threats to the native freshwater fishes of the country are invasive fish species, deterioration of water quality, impoundments and excessive water abstraction, land use changes and modification of riverine habitats. Immediate conservation efforts should focus on securing remnant populations of highly threatened taxa and preventing deterioration in threat status, because recovery is rare. Accurate delimitation of species boundaries, mapping their distribution ranges, improved knowledge of pressures and long-term monitoring of population trends need to be prioritised to generate credible data for the 2026 IUCN threat status assessments and designation of important fish areas as part of the National Freshwater Ecosystem Priority Areas (NFEPA) initiative.
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Affiliation(s)
- Albert Chakona
- NRF-South African Institute for Aquatic Biodiversity (NRF-SAIAB), Makhanda (Grahamstown), South Africa
- Department of Ichthyology and Fisheries Science, Rhodes University, Makhanda (Grahamstown), South Africa
| | - Martine S Jordaan
- NRF-South African Institute for Aquatic Biodiversity (NRF-SAIAB), Makhanda (Grahamstown), South Africa
- CapeNature Biodiversity Capabilities Unit, Stellenbosch
- Center of Excellence for Invasion Biology, CapeNature Biodiversity Capabilities Unit, Stellenbosch
| | - Domitilla C Raimondo
- South African National Biodiversity Institute Threatened Species Program, Kirstenbosch National Botanical Gardens, Cape Town
| | - Roger I Bills
- NRF-South African Institute for Aquatic Biodiversity (NRF-SAIAB), Makhanda (Grahamstown), South Africa
| | - Paul H Skelton
- NRF-South African Institute for Aquatic Biodiversity (NRF-SAIAB), Makhanda (Grahamstown), South Africa
| | - Dewidine van der Colff
- Center of Excellence for Invasion Biology, CapeNature Biodiversity Capabilities Unit, Stellenbosch
- South African National Biodiversity Institute Threatened Species Program, Kirstenbosch National Botanical Gardens, Cape Town
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5
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Mazungula DN, Chakona A. An integrative taxonomic review of the Natal mountain catfish, Amphilius natalensis Boulenger 1917 (Siluriformes, Amphiliidae), with description of four new species. JOURNAL OF FISH BIOLOGY 2021; 99:219-239. [PMID: 33635552 DOI: 10.1111/jfb.14714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 02/18/2021] [Accepted: 02/23/2021] [Indexed: 06/12/2023]
Abstract
An integrative taxonomic analysis combining mitochondrial cytochrome oxidase subunit I sequences, morphology, colour pattern and two species delimitation approaches revealed the existence of five lineages within the Natal mountain catfish, Amphilius natalensis, in southern Africa. These lineages are separated by substantial genetic divergences (1.6%-9.46%), and they can be consistently distinguished from one another based on a combination of morphology and colour pattern differences. Additionally, the lineages are allopatrically distributed and confined to isolated river systems draining discrete mountain ranges, which makes gene flow among them unlikely. One of these lineages is A. natalensis s.s., which is confined to the uMngeni and Tukela river systems in KwaZulu Natal (KZN) Province in South Africa. The other four lineages represent new species to science which are described as Amphilius zuluorum sp. nov., endemic to the uMkhomazi River system in KZN, Amphilius engelbrechti sp. nov., endemic to the Inkomati River system in Mpumalanga Province in South Africa, Amphilius marshalli sp. nov., endemic to the Pungwe and Lower Zambezi river systems in Zimbabwe and Mozambique, and Amphilius leopardus sp. nov., endemic to the Ruo River in Malawi. The results show that Amphilius laticaudatus which is endemic to the Buzi River system in Zimbabwe and Mozambique, belongs to the A. natalensis s.l. complex. A redescription of A. laticaudatus is presented and an updated identification key for the mountain catfishes of southern Africa is provided.
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Affiliation(s)
- Daniel Nkosinathi Mazungula
- National Research Foundation - South African Institute for Aquatic Biodiversity, Makhanda (Grahamstown), South Africa
- Department of Ichthyology and Fisheries Science, Rhodes University, Makhanda (Grahamstown), South Africa
| | - Albert Chakona
- National Research Foundation - South African Institute for Aquatic Biodiversity, Makhanda (Grahamstown), South Africa
- Department of Ichthyology and Fisheries Science, Rhodes University, Makhanda (Grahamstown), South Africa
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6
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Jirsová D, Štefka J, Blažek R, Malala JO, Lotuliakou DE, Mahmoud ZN, Jirků M. From taxonomic deflation to newly detected cryptic species: Hidden diversity in a widespread African squeaker catfish. Sci Rep 2019; 9:15748. [PMID: 31673053 PMCID: PMC6823466 DOI: 10.1038/s41598-019-52306-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/16/2019] [Indexed: 11/21/2022] Open
Abstract
Cryptic genetic diversity and erroneous morphological species determination represent frequent problems in biodiversity research. Here, examination of 138 specimens of Synodontis (Mochokidae, Siluriformes) from the Nile River and Lake Turkana revealed the presence of both S. schall-like and S. frontosus-like morphotypes, with a phenotypic gradient between them. We concluded phylogenetic and population genetic analyses based on two mitochondrial and one nuclear marker including 131 coxI (565 bp), 96 cytb (973 bp) and 19 RAG2 (896 bp) sequences from the Nile-Turkana population, plus additional GenBank data of Synodontis spp. Whilst nuclear data were inconclusive, mitochondrial sequences suggested that both morphotypes and intermediate forms are conspecific. The results imply probable synonymy of S. frontosus with S. schall. Conversely, a strong biogeographical signal was revealed among widely distributed and supposedly conspecific S. schall-like catfish of the Nilo-Sudanian ichthyological province. Synodontis schall sensu stricto (=Eastern clade), as defined by type locality in the Nile, is apparently restricted to the eastern part of the Nilo-Sudanian ichthyological province (e.g. Nile, Turkana, Chad). Synodontis schall Western clade (Senegambia, Niger, Chad) most probably represents a cryptic taxon, unrecognized thus far due to the absence of distinctive morphological differences.
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Affiliation(s)
- Dagmar Jirsová
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České, Budějovice, Czech Republic.
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05, České, Budějovice, Czech Republic.
| | - Jan Štefka
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České, Budějovice, Czech Republic
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05, České, Budějovice, Czech Republic
| | - Radim Blažek
- Institute of Vertebrate Biology, Czech Academy of Sciences, Květná 8, 603 65, Brno, Czech Republic
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic
| | - John O Malala
- Kenya Marine and Fisheries Research Institute, Lake Turkana Station, P.O. Box 205, 30500, Lodwar, Kenya
| | - David E Lotuliakou
- Kenya Marine and Fisheries Research Institute, Lake Turkana Station, P.O. Box 205, 30500, Lodwar, Kenya
| | - Zuheir N Mahmoud
- Department of Zoology, Faculty of Science, University of Khartoum, 111 15, Khartoum, Sudan
| | - Miloslav Jirků
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05, České, Budějovice, Czech Republic
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Chakona A, Kadye WT, Bere T, Mazungula DN, Vreven E. Evidence of hidden diversity and taxonomic conflicts in five stream fishes from the Eastern Zimbabwe Highlands freshwater ecoregion. Zookeys 2018:69-95. [PMID: 29955212 PMCID: PMC6019476 DOI: 10.3897/zookeys.768.21944] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 04/25/2018] [Indexed: 11/25/2022] Open
Abstract
Stream fishes of the Eastern Afromontane region are among the least studied vertebrates in this region, despite the potential for harbouring cryptic diversity. The present study examined mitochondrial cytochrome oxidase subunit I (COI) sequence divergence in 153 specimens of stream fishes belonging to four genera and three families, [(Amphilius and Zaireichthys (Amphiliidae); Chiloglanis (Mochokidae); and Hippopotamyrus (Mormyridae)], in the Eastern Zimbabwe Highlands (EZH) freshwater ecoregion to explore the extent to which the current taxonomy conceals the ichthyofaunal diversity in the region. The General Mixed Yule Coalescent (GMYC) species delineation method identified 14 clusters within five currently recognised ‘species’ from the EZH ecoregion. Only one of these clusters represents a named species, while 13 of them represent candidate or undescribed species. Our results revealed that effective conservation of this region’s unique biota is limited by the incomplete knowledge of taxonomic diversity and inaccurate mapping of species distribution ranges.
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Affiliation(s)
- Albert Chakona
- South African Institute for Aquatic Biodiversity, Private Bag 1015, Grahamstown, South Africa, 6140.,Department of Ichthyology and Fisheries Science, Rhodes University, P.O. Box 94, Grahamstown, South Africa, 6140
| | - Wilbert T Kadye
- Department of Ichthyology and Fisheries Science, Rhodes University, P.O. Box 94, Grahamstown, South Africa, 6140
| | - Taurai Bere
- School of Wildlife, Ecology and Conservation, Chinhoyi University of Technology, P. Bag 7724, Chinhoyi, Zimbabwe
| | - Daniel N Mazungula
- South African Institute for Aquatic Biodiversity, Private Bag 1015, Grahamstown, South Africa, 6140.,Department of Ichthyology and Fisheries Science, Rhodes University, P.O. Box 94, Grahamstown, South Africa, 6140
| | - Emmanuel Vreven
- Royal Museum for Central Africa, Section of Vertebrates, Ichthyology, Leuvensesteenweg 13, 3080, Tervuren, Belgium.,KU Leuven, Department of Biology, Laboratory of Biodiversity and Evolutionary Genomics, Deberiotstraat 32, 3000 Leuven, Belgium
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8
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Outomuro D, Johansson F. A potential pitfall in studies of biological shape: Does size matter? J Anim Ecol 2017; 86:1447-1457. [PMID: 28699246 DOI: 10.1111/1365-2656.12732] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 06/21/2017] [Indexed: 01/26/2023]
Abstract
The number of published studies using geometric morphometrics (GM) for analysing biological shape has increased steadily since the beginning of the 1990s, covering multiple research areas such as ecology, evolution, development, taxonomy and palaeontology. Unfortunately, we have observed that many published studies using GM do not evaluate the potential allometric effects of size on shape, which normally require consideration or assessment. This might lead to misinterpretations and flawed conclusions in certain cases, especially when size effects explain a large part of the shape variation. We assessed, for the first time and in a systematic manner, how often published studies that have applied GM consider the potential effects of allometry on shape. We reviewed the 300 most recent published papers that used GM for studying biological shape. We also estimated how much of the shape variation was explained by allometric effects in the reviewed papers. More than one-third (38%) of the reviewed studies did not consider the allometric component of shape variation. In studies where the allometric component was taken into account, it was significant in 88% of the cases, explaining up to 87.3% of total shape variation. We believe that one reason that may cause the observed results is a misunderstanding of the process that superimposes landmark configurations, i.e. the Generalized Procrustes Analysis, which removes isometric effects of size on shape, but not allometric effects. Allometry can be a crucial component of shape variation. We urge authors to address, and report, size effects in studies of biological shape. However, we do not propose to always remove size effects, but rather to evaluate the research question with and without the allometric component of shape variation. This approach can certainly provide a thorough understanding of how much size contributes to the observed shaped variation.
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Affiliation(s)
- David Outomuro
- Section for Animal Ecology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
| | - Frank Johansson
- Section for Animal Ecology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
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Basiita RK, Zenger KR, Jerry DR. Populations genetically rifting within a complex geological system: The case of strong structure and low genetic diversity in the migratory freshwater catfish, Bagrus docmak, in East Africa. Ecol Evol 2017; 7:6172-6187. [PMID: 28861223 PMCID: PMC5574809 DOI: 10.1002/ece3.3153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 03/31/2017] [Accepted: 04/24/2017] [Indexed: 11/18/2022] Open
Abstract
The complex geological history of East Africa has been a driving factor in the rapid evolution of teleost biodiversity. While there is some understanding of how macroevolutionary drivers have shaped teleost speciation in East Africa, there is a paucity of research into how the same biogeographical factors have affected microevolutionary processes within lakes and rivers. To address this deficiency, population genetic diversity, demography, and structure were investigated in a widely distributed and migratory (potamodromous) African teleost species, Ssemutundu (Bagrus docmak). Samples were acquired from five geographical locations in East Africa within two major drainage basins; the Albertine Rift and Lake Victoria Basin. Individuals (N = 175) were genotyped at 12 microsatellite loci and 93 individuals sequenced at the mitochondrial DNA control region. Results suggested populations from Lakes Edward and Victoria had undergone a severe historic bottleneck resulting in very low nucleotide diversity (π = 0.004 and 0.006, respectively) and negatively significant Fu values (-3.769 and -5.049; p < .05). Heterozygosity deficiencies and restricted effective population size (NeLD) suggested contemporary exposure of these populations to stress, consistent with reports of the species decline in the East African Region. High genetic structuring between drainages was detected at both historical (ɸST = 0.62 for mtDNA; p < .001) and contemporary (microsatellite FST = 0.460; p < .001) levels. Patterns of low genetic diversity and strong population structure revealed are consistent with speciation patterns that have been linked to the complex biogeography of East Africa, suggesting that these biogeographical features have operated as both macro- and micro-evolutionary forces in the formation of the East African teleost fauna.
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Affiliation(s)
- Rose Komugisha Basiita
- Centre for Sustainable Tropical Fisheries and Aquaculture and College of Marine and Environmental SciencesJames Cook UniversityTownsvilleQldAustralia
- National Agricultural Research OrganizationNational Fisheries Resources Research InstituteAquaculture Research and Development Center KajjansiKampalaUganda
| | - Kyall Richard Zenger
- Centre for Sustainable Tropical Fisheries and Aquaculture and College of Marine and Environmental SciencesJames Cook UniversityTownsvilleQldAustralia
| | - Dean Robert Jerry
- Centre for Sustainable Tropical Fisheries and Aquaculture and College of Marine and Environmental SciencesJames Cook UniversityTownsvilleQldAustralia
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10
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Schmidt RC, Bart HL, Pezold F, Friel JP. A Biodiversity Hotspot Heats Up: Nine New Species of Suckermouth Catfishes (Mochokidae:Chiloglanis) from Upper Guinean Forest Streams in West Africa. COPEIA 2017. [DOI: 10.1643/ci-16-474] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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11
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Schmidt RC, Bart HL, Nyingi WD. Multi-locus phylogeny reveals instances of mitochondrial introgression and unrecognized diversity in Kenyan barbs (Cyprininae: Smiliogastrini). Mol Phylogenet Evol 2017; 111:35-43. [PMID: 28323052 DOI: 10.1016/j.ympev.2017.03.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 03/05/2017] [Accepted: 03/16/2017] [Indexed: 10/19/2022]
Abstract
The phylogenetics and taxonomic status of small African barbs (Cyprininae: Smiliogastrini) remains unresolved despite the recent decision to elevate the genus name Enteromius for the group. The main barrier to understanding the origin of African small barbs and evolutionary relationships within the group is the poor resolution of phylogenies published to date. These phylogenies usually rely on mitochondrial markers and have limited taxon sampling. Here we investigate the phylogenetic relationships of small barbs of Kenya utilizing cytochrome b, Growth Hormone (GH) intron 2, and RAG1 markers from multiple populations of many species in the region. This multi-locus study produced well-supported phylogenies and revealed additional issues that complicate understanding the relationships among East African barbs. We observed widespread mtDNA introgression within the Kenyan barbs, highlighting the need to include nuclear markers in phylogenetic studies of the group. The GH intron 2 resolved heterospecific individuals and aided in inferring the species level phylogeny. The study reveals unrecognized diversity within the group, including within species reported to occur throughout East Africa, and it provides the groundwork for future taxonomic work in the region and across Africa.
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Affiliation(s)
- Ray C Schmidt
- Department of Ecology and Evolutionary Biology, Tulane University, 400 Boggs Hall, New Orleans, LA 70118, United States; Smithsonian Institution, Smithsonian Mpala Postdoctoral Fellow, Mpala Research Centre, PO Box 555-10400, Nanyuki, Kenya.
| | - Henry L Bart
- Department of Ecology and Evolutionary Biology, Tulane University, 400 Boggs Hall, New Orleans, LA 70118, United States
| | - Wanja Dorothy Nyingi
- Ichthyology Section, National Museums of Kenya, PO Box 40658-00100, Nairobi, Kenya
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12
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Schmidt RC, Bart HL, Pezold F. High levels of endemism in suckermouth catfishes (Mochokidae: Chiloglanis) from the Upper Guinean forests of West Africa. Mol Phylogenet Evol 2016; 100:199-205. [DOI: 10.1016/j.ympev.2016.04.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 04/11/2016] [Accepted: 04/12/2016] [Indexed: 10/21/2022]
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