DOCSLIB.ORG

Some Aspects of the Biology of Distichodus Rostratus (GUNTHER, 1864) in River Rima, North-Western Nigeria

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Some Aspects of the Biology of Distichodus Rostratus (GUNTHER, 1864) in River Rima, North-Western Nigeria Greener Journal of xxxxxxxxxxxxxxxxxxxxx ISSN: xxxxxxxxxxx Vol. x (x), pp. xxx-xxx, Month 2013. ISSN: 2276-7762 Impact Factor 2012 (UJRI): 0.7361 ICV 2012: 5.99 Some Aspects of the Biology of Distichodus rostratus (GUNTHER, 1864) in River Rima, North-western Nigeria By Shinkafi B.A . Salim A.M. Yusuf M.A. www.gjournals.org 135 Greener Journal of Biological Sciences ISSN: 2276-7762 Vol. 3 (4), pp. 136-145, May 2013. Research Article Some Aspects of the Biology of Distichodus rostratus (GUNTHER, 1864) in River Rima, North-western Nigeria *Shinkafi B.A., Salim A.M. and Yusuf M.A. Department of Forestry and Fisheries, Faculty of Agriculture, Usmanu Danfodiyo University, Sokoto, Nigeria. *Corresponding Author’s Email: [email protected] , Tel: +2348137844490 Abstract Study was carried out to determine some aspects of the biology of Distichodus rostratus (GUNTHER, 1864) in River Rima, North-western Nigeria. This is with a view to provide information on the species in River Rima which has not been documented elsewhere. These include morphometric measurements, growth pattern, diet composition, gonad maturation stages, gonadosomatic index (GSI) and fecundity of the species. A total of 66 samples were collected from Kwalkwalawa fish landing site of River Rima between July and December, 2012. Total length of the samples ranged from 18.70±0.99SE to 46.20±0.99SE with a mean value of 31.18±0.99SE while total weight ranged from 104.20±32.65SE to 892.60±32.65SE with a mean value of 473.92±32.65SE. The b values of 2.461, 2.476 and 2.292 for all samples, females and males respectively indicate negative allometry. Mean condition factor was 1.52±0.517SD, indicating that the species are in good condition. Analysis of the stomach contents revealed that the species are herbivorous feeding mainly on leaves and roots of aquatic plants, grasses, algae and deadwood. Observation of the structural feeding adaptations such as the sub-inferior mouth, the fine and numerous gill rakers, the U-shaped stomach and the long intestine further confirms the herbivorous nature of the fish. Four stages of gonad maturation were established in females and three stages in males. Gonadosomatic index values for males ranged from 0.08 to 1.20% with mean value of 0.25±0.0211SE and for females 0.25 to 2.29%, with a mean value of 1.89±0.829SE. Fecundity ranged from 2,980 – 21,010 eggs. Key words: D. rostratus , Growth pattern, Stomach content, Fecundity, River Rima. Introduction Distichodus rostratus , commonly known as the grass eater, belongs to the Family Distichodontidae. According to Nelson (2006), the species are found in fresh water. The species plays an important role in the ecosystem and fisheries of West Africa and other inland waters, as it constitutes an important trophic web of ecosystem and has been introduced into many artificial lakes and reservoirs such as Kiru, Kariba and Tiga Dams in parts of Africa (Coulter, 1970). The species are among the major exploitable fish species and are widely distributed in Nigeria, Nilo- Sudan, Niger, Volta, Chad and Nile basins (Teugels et al, 1992). Prior to their introduction into artificial lakes, they had colonized artificial lakes from natural riverine habitats (Abowei, 2010). Distichodus rostratus lives along the grassy banks of rivers and swamps and they are extremely fecund with their ovaries containing a great number of eggs and can attain a length of more than 60cm and above 6kg in northern Nigerian waters (Reed et al. , 1967; Motwani and Kanwai, 1970). In Nigeria, Distichodus spp are cultured in fish farms and numerous lentic water bodies due to their ability to feed on grasses and weeds (Nwani and Ude, 2005). Comprehensive knowledge of growth and reproduction of fish populations is important for increased fish production in natural waters and in aquaculture. Growth parameters are important in the selection of fishes for culture and in estimating food consumption of fish populations (King, 1997). The mathematical parameters of the relationship between the length and weight of a fish furnish further information on the weight variation of individuals in relation to the length; that is condition factor, which estimates the general well-being of an individual (Benedito-Cecilio et al ., 1997). Reproduction is of special interest to fisheries managers, since successful reproduction ensures recruits for the fisheries for years to come, and thus, fisheries managers must consider anything that concerns reproduction when regulating fisheries (Williams, 2007). Fecundity assessments have been useful in racial distinction , progeny www.gjournals.org 136 Greener Journal of Biological Sciences ISSN: 2276-7762 Vol. 3 (4), pp. 136-145, May 2013. survival studies, stock evaluation and aquaculture-based induced spawning and egg incubation (Bagenal, 1978; Marcus, 1982; Coates, 1988). Gonadosomatic index has been used thoroughly as an indicator of the spawning period of teleosts, and its use in reproductive biology has been considered more appropriate when used with other indicators of reproduction such as macroscopic observations (De Vlaming, 1972). A record of the stage of gonad maturity is required for many purposes, such as for determining the proportion of stock that is mature, or the size or age at first maturity (Bagenal, 1978). Maturity stage is also employed by biologists to determine the reproductive potential of fish populations and monitor changes in biological characteristics of exploited fish stocks (Williams, 2007). Many studies were carried out on various aspects of the biology of D. rostratus in water bodies from Nigeria (Arawomo (1982); Inyang and Nwani (2004); Nwani and Ude (2005); Nwani, (2006); Abowei and Hart (2009) and Abowei, 2010). So far, no work has been reported on the biology of this important fish species in River Rima. This study therefore is intended to provide a baseline data on some aspects of growth and reproductive biology of D. rostratus in River Rima, North-western Nigeria. 2. Materials and Methods 2.1 Study Area The fish samples were collected from River Rima, in Sokoto, North-western Nigeria. Sokoto lies between longitudes 4o8’E and 6 o5’E, and latitudes 12 oN and 13 o58’N (Mamman, 2000). The climate of Sokoto is tropical continental, with much of the rains between June and September, while the long dry season is from October and May (Ita et al. , 1982). River Rima flows in a South-western direction over 100km and joins the major River Sokoto to form the Sokoto-Rima river system. The Sokoto-Rima River flows South-westerly in a direction up to Zogirma, where it changes direction and run Southwards before emptying into River Niger. The River is seasonal, usually over flooding its banks during the rainy season in August and September, and up to October at times (Mock, 1963). 2.2 Collection of Specimens Samples of Distichodus rostratus were collected in batches from Kwalkwalawa fish landing site. Identification was based on the descriptions of Reed et al . (1967), Holden and Reed (1972) and Olaosebikan and Raji (1998). The fishing gears used was mainly cast nets, gill nets and seine nets. Samples were collected on monthly basis for a period of six months (July- December, 2012). 2.3 Laboratory procedures and data collection In the laboratory, samples were examined fresh immediately after collection. On each sample, length parameters such as total length (TL) and standard length (SL), were all measured using a metric ruler (in cm) and weight parameters such as the total weight (TW) and gutted weight (GW) were all weighed using Metler top-loading balance (in g). Sex of the specimens was determined after dissection based on the presence of testis and ovary. The gut of the fish was removed by making a longitudinal incision along the mid-ventral line from the mouth to the anus to expose the visceral organs. The gut was removed carefully by detaching it from other internal organs and fatty tissues. The gut length (GL) was then measured to the nearest cm on a graduated measuring board. The stomach was cut off from the gut and scored 0%, 25%, 50%, 75% or 100% according to its fullness as described by Olatunde (1979). This will also give an insight on the feeding intensity of the fish (Ogbeibu and Ezeunara, 2005). Stomachs were sliced open and its contents placed into a Petri dish and analysed using frequency of occurrence method as described by Hynes (1950). Each food item was identified, and the number of stomachs in which the food item occurred were counted and expressed as a percentage of all the stomachs with food. The structural feeding adaptations such as the mouth, the gill rakers, the stomach and the intestine were observed to further confirm the feeding nature of the species. Gonads were detached and weighed (in g). Length and width (cm) of each gonad lobe were measured. Other morphological features of the gonads such as the degree of opacity of the gonads, consistency and vascularization, oocytes or sperm visibility and overall colouration of the gonads were observed. Same features were used to determine the gonad maturity stages (White et al ., 1998). Fecundity was determined by gravimetric sub- sampling method (wet method) as described by Bagenal (1978). www.gjournals.org 137 Greener Journal of Biological Sciences ISSN: 2276-7762 Vol. 3 (4), pp. 136-145, May 2013. 2.4 Statistical Analysis 2.4.1 Growth studies - Growth pattern was analyzed based on the formula: . Logarithmic transformation equation of length-weight relationship was made to give a linear one as: (Bagenal and Tesch, 1978). Where: W = Weight of fish (g); L = Length of fish (cm); a = constant; b = exponent. The values of ‘a’ and ‘b’ are estimated by least squares regression analysis (Zar, 1984).
Load more

Recommended publications
  • Phylogenetic Relationships Within the Speciose Family Characidae
    Oliveira et al. BMC Evolutionary Biology 2011, 11:275 http://www.biomedcentral.com/1471-2148/11/275 RESEARCH ARTICLE Open Access Phylogenetic relationships within the speciose family Characidae (Teleostei: Ostariophysi: Characiformes) based on multilocus analysis and extensive ingroup sampling Claudio Oliveira1*, Gleisy S Avelino1, Kelly T Abe1, Tatiane C Mariguela1, Ricardo C Benine1, Guillermo Ortí2, Richard P Vari3 and Ricardo M Corrêa e Castro4 Abstract Background: With nearly 1,100 species, the fish family Characidae represents more than half of the species of Characiformes, and is a key component of Neotropical freshwater ecosystems. The composition, phylogeny, and classification of Characidae is currently uncertain, despite significant efforts based on analysis of morphological and molecular data. No consensus about the monophyly of this group or its position within the order Characiformes has been reached, challenged by the fact that many key studies to date have non-overlapping taxonomic representation and focus only on subsets of this diversity. Results: In the present study we propose a new definition of the family Characidae and a hypothesis of relationships for the Characiformes based on phylogenetic analysis of DNA sequences of two mitochondrial and three nuclear genes (4,680 base pairs). The sequences were obtained from 211 samples representing 166 genera distributed among all 18 recognized families in the order Characiformes, all 14 recognized subfamilies in the Characidae, plus 56 of the genera so far considered incertae sedis in the Characidae. The phylogeny obtained is robust, with most lineages significantly supported by posterior probabilities in Bayesian analysis, and high bootstrap values from maximum likelihood and parsimony analyses.
    [Show full text]
  • A Guide to the Parasites of African Freshwater Fishes
    A Guide to the Parasites of African Freshwater Fishes Edited by T. Scholz, M.P.M. Vanhove, N. Smit, Z. Jayasundera & M. Gelnar Volume 18 (2018) Chapter 2.1. FISH DIVERSITY AND ECOLOGY Martin REICHARD Diversity of fshes in Africa Fishes are the most taxonomically diverse group of vertebrates and Africa shares a large portion of this diversity. This is due to its rich geological history – being a part of Gondwana, it shares taxa with the Neotropical region, whereas recent close geographical affnity to Eurasia permitted faunal exchange with European and Asian taxa. At the same time, relative isolation and the complex climatic and geological history of Africa enabled major diversifcation within the continent. The taxonomic diversity of African freshwater fshes is associated with functional and ecological diversity. While freshwater habitats form a tiny fraction of the total surface of aquatic habitats compared with the marine environment, most teleost fsh diversity occurs in fresh waters. There are over 3,200 freshwater fsh species in Africa and it is likely several hundreds of species remain undescribed (Snoeks et al. 2011). This high diversity and endemism is likely mirrored in diversity and endemism of their parasites. African fsh diversity includes an ancient group of air-breathing lungfshes (Protopterus spp.). Other taxa are capable of breathing air and tolerate poor water quality, including several clariid catfshes (e.g., Clarias spp.; Fig. 2.1.1D) and anabantids (Ctenopoma spp.). Africa is also home to several bichir species (Polypterus spp.; Fig. 2.1.1A), an ancient fsh group endemic to Africa, and bonytongue Heterotis niloticus (Cuvier, 1829) (Osteoglossidae), a basal actinopterygian fsh.
    [Show full text]
  • DNA Barcoding Reveals Novel Insights Into Pterygophagy and Prey Selection in Distichodontid fishes (Characiformes: Distichodontidae) Jairo Arroyave & Melanie L
    DNA barcoding reveals novel insights into pterygophagy and prey selection in distichodontid fishes (Characiformes: Distichodontidae) Jairo Arroyave & Melanie L. J. Stiassny Division of Vertebrate Zoology, Department of Ichthyology, American Museum of Natural History, Central Park West at 79th St., New York, New York 10024 Keywords Abstract Ectoparasitic fin-eating behaviors, mtDNA, stomach contents, trophic ecology. DNA barcoding was used to investigate dietary habits and prey selection in members of the African-endemic family Distichodontidae noteworthy for dis- Correspondence playing highly specialized ectoparasitic fin-eating behaviors (pterygophagy). Fin Jairo Arroyave, Division of Vertebrate fragments recovered from the stomachs of representatives of three putatively Zoology, Department of Ichthyology, pterygophagous distichodontid genera (Phago, Eugnathichthys, and Ichthyborus) American Museum of Natural History, were sequenced for the mitochondrial gene co1. DNA barcodes (co1 sequences) Central Park West at 79th St., New York, were then used to identify prey items in order to determine whether pterygo- NY 10024 Tel: +1 212 769 5841, Fax: 212 769 5642; phagous distichodontids are opportunistic generalists or strict specialists with E-mail: [email protected] regard to prey selection and, whether as previously proposed, aggressive mim- icry is used as a strategy for successful pterygophagy. Our findings do not sup- Funding Information port the hypothesis of aggressive mimicry suggesting instead that, despite the The Department of Ichthyology of the possession of highly specialized trophic anatomies, fin-eating distichodontids American Museum of Natural History are opportunistic generalists, preying on fishes from a wide phylogenetic spec- (AMNH) through the Axelrod Research trum and to the extent of engaging in cannibalism. This study demonstrates Curatorship provided the bulk of funding for this study.
    [Show full text]
  • 16. Distichodontidae = 16. Distichodontidae
    16. DISTICHODONTIDAE Richard P. VARI Les poissons de la famille des Distichodontidae constituent un assemblage modérément diversifié au sein des Characiformes dont les membres sont endémiques aux systèmes d’eau douce à travers l’Afrique sub-saharienne et le long du bassin du Nil. Les membres de la famille montrent une gamme remarquable de morphologies, en particulier de leurs mâchoires, qui reflètent la diversité de leurs habitudes alimentaires. Les membres de la famille peuvent aisément se distinguer des autres characiformes africains par la combinaison de la présence de vraies écailles cténoïdes avec les ctenii formés d’une série d’ossifications indépendantes le long du bord postérieur de l’écaille et en ayant au moins quelques dents bicuspides à chaque mâchoire. Quinze genres de Distichodontidae sont connus dont dix, comme définis par VARI (1979), apparaissent en basse Guinée et sont répartis en 26 espèces. Comme mentionné dans le chapitre « Espèces étrangères ou introduites en basse Guinée », il a été observé que Distichodus niloticus fut introduit en basse Guinée. Toutefois, la présence de Distichodus niloticus dans la région n’est pas confirmée par les données des musées. CLÉ 1 Prémaxillaire très mobile et pivotant verticalement sur le crâne. DES GENRES Maxillaire très réduit, étroitement et strictement attaché à la partie postérieure du prémaxillaire (fig 16.1B) ........................ 2 Mâchoire supérieure immobile ou seulement très peu mobile par rapport au crâne. Maxillaire très développé et mobile par rapport au prémaxillaire (fig. 16.1A) .................................................... 5 2 Mâchoire supérieure modérément développée, avec la série unique de dents sur le prémaxillaire interrompue dans la région près de la symphyse ....................................
    [Show full text]
  • (Characiformes: Citharinoidei) from the Congo Basin of Central Africa, with a Molecular Phylogeny for the Genus
    Zootaxa 3693 (4): 479–490 ISSN 1175-5326 (print edition) www.mapress.com/zootaxa/ Article ZOOTAXA Copyright © 2013 Magnolia Press ISSN 1175-5334 (online edition) http://dx.doi.org/10.11646/zootaxa.3693.4.4 http://zoobank.org/urn:lsid:zoobank.org:pub:13EA08B0-9D7C-4845-854C-FECC3C9580F1 A new ectoparasitic distichodontid of the genus Eugnathichthys (Characiformes: Citharinoidei) from the Congo basin of central Africa, with a molecular phylogeny for the genus MELANIE L.J. STIASSNY1 JOHN S.S. DENTON1,2 & RAOUL J.C. MONSEMBULA IYABA3 1American Museum of Natural History, Department of Ichthyology, Central Park West at 79th Street, New York, New York 10024. E-mail: [email protected] 2Richard Gilder Graduate School, American Museum of Natural History, Central Park West at 79th Street, New York, New York 10024. E-mail:[email protected] 3Faculté des Sciences, Département de Biologie, Université de Kinshasa B.P 190 Kin XI, Democratic Republic of Congo. E-mail: [email protected] Abstract A new species of ectoparasitic distichodontid, Eugnathichthys virgatus, is described from localities in the central and western Congo basin. The new species is a fin-eater even at small sizes and, in common with congeners, is capable of biting off sections of heavily ossified fin-rays of large prey species. Prior to the present study, two species were included in this distinctive distichodontid genus: the type species, Eugnathichthys eetveldii, and a second species, E. macroterole- pis, both of which are widely distributed throughout much of the Congo basin. Morphologically, E. virgatus is readily dis- tinguished from its two congeners based on a combination of meristic and morphometric attributes.
    [Show full text]
  • New Species of Creagrutus (Teleostei: Characiformes: Characidae) from the Rı´O Magdalena Basin, Colombia
    Copeia, 2005(4), pp. 812–817 New Species of Creagrutus (Teleostei: Characiformes: Characidae) from the Rı´o Magdalena Basin, Colombia MAURICIO TORRES-MEJIA AND RICHARD P. VARI A new species of Creagrutus from the Rı´o Magdalena basin, Colombia, is described. This species is distinguished from all congeners by a combination of morphometric, meristic, and morphological features. The species is the first member of the genus known to have breeding tubercles with keratinized caps. The phylogenetic position of the new species and various aspects of its ecology and behavior are discussed. Es descrita una nueva especie de Creagrutus de la cuenca del Rı´o Magdalena, Colombia. E´ sta especie se distingue de sus conge´neres por su combinacio´n de caracterı´sticas morfome´tricas, merı´sticas y morfolo´gicas. E´ sta es la primera especie de Creagrutus en la que se hayan observado tube´rculos reproductivos con casquetes queratinizados. Se discute la posicio´n filogene´tica de la nueva especie y se comentan varios aspectos de su ecologı´a y comportamiento. AROLD and Vari (1994) and Vari and Lima, 2003) and C. varii (Ribeiro et al., 2004). H Harold (2001), respectively revised the This analysis was carried out using Nona (vers. trans- and cis-Andean species of Creagrutus. Even 2.0, P. S. Goloboff, Fundacio´n e Instituto Miguel though those authors dramatically increased the Lillo, Tucuma´n, Argentina) with the RAS-TBR number of recognized species within Creagrutus, heuristic method (h/1, h 10000, 500 iterations, it is striking that the species-level diversity within 100 replicates); the resulting trees were observed the genus continues to rise as a consequence of with WinClada (vers.
    [Show full text]
  • Parodon Orinocensis(Bonilla Et Al., 1999) (Characiformes: Parodontidae)
    Neotropical Ichthyology, 10(3):561-566, 2012 Copyright © 2012 Sociedade Brasileira de Ictiologia Parodon orinocensis (Bonilla et al., 1999) (Characiformes: Parodontidae): emendations and generic reallocation Leonardo F. S. Ingenito1,, Carla S. Pavanelli2 and Francisco Provenzano3 During recent studies on Parodontidae, specimens of the Venezuelan species Parodon orinocensis (Bonilla, Machado-Allison, Silvera, Chernoff, López & Lasso, 1999) were examined and a few incongruencies with the original description of the species were noted. Emendations to the descriptions of the jaw teeth and color pattern are presented. Three autapomorphies were also observed and are listed herein. The species is moved from genus Apareiodon to Parodon based on presence of dentary teeth. Durante estudos recentes sobre Parodontidae, espécimes da espécie venezuelana Parodon orinocencis (Bonilla, Machado- Allison, Silvera, Chernoff, López & Lasso, 1999) foram examinados e reconhecidas algumas incongruências na descrição original. Foram realizadas retificações relacionadas aos dentes das maxilas e ao padrão de coloração. Três autapomorfias foram observadas e são aqui listadas. Com base na presença de dentes no dentário a espécie é transferida do gênero Apareiodon para o gênero Parodon. Key words: Freshwater fish, Neotropical, Ostariophysi, Río Orinoco basin, Taxonomy. Introduction from that basin, A. orinocensis. Based on the classic tooth characterization of the parodontid genera, those authors Parodontidae Eigenmann, 1910 is a small characiform allocated their new species to the genus Apareiodon, since family composed by three currently valid genera, Parodon the species was held to have an edentulous lower jaw. After Valenciennes, 1849, Saccodon Kner, 1863 and Apareiodon examining extensive parodontid material from Venezuela, Eigenmann, 1916, and 32 valid species (Pavanelli, 1999; including the holotype (MBUCV-V 29170) and paratypes Pavanelli, 2003; Pavanelli & Britski, 2003; Ingenito & Buckup, (MBUCV-V 26669) of A.
    [Show full text]
  • AMNH-Scientific-Publications-2014
    AMERICAN MUSEUM OF NATURAL HISTORY Fiscal Year 2014 Scientific Publications Division of Anthropology 2 Division of Invertebrate Zoology 11 Division of Paleontology 28 Division of Physical Sciences 39 Department of Earth and Planetary Sciences and Department of Astrophysics Division of Vertebrate Zoology Department of Herpetology 58 Department of Ichthyology 62 Department of Mammalogy 65 Department of Ornithology 78 Center for Biodiversity and Conservation 91 Sackler Institute for Comparative Genomics 99 DIVISION OF ANTHROPOLOGY Berwick, R.C., M.D. Hauser, and I. Tattersall. 2013. Neanderthal language? Just-so stories take center stage. Frontiers in Psychology 4, article 671. Blair, E.H., and Thomas, D.H. 2014. The Guale uprising of 1597: an archaeological perspective from Mission Santa Catalina de Guale (Georgia). In L.M. Panich and T.D. Schneider (editors), Indigenous Landscapes and Spanish Missions: New Perspectives from Archaeology and Ethnohistory: 25–40. Tucson: University of Arizona Press. Charpentier, V., A.J. de Voogt, R. Crassard, J.-F. Berger, F. Borgi, and A. Al- Ma’shani. 2014. Games on the seashore of Salalah: the discovery of mancala games in Dhofar, Sultanate of Oman. Arabian Archaeology and Epigraphy 25: 115– 120. Chowns, T.M., A.H. Ivester, R.L. Kath, B.K. Meyer, D.H. Thomas, and P.R. Hanson. 2014. A New Hypothesis for the Formation of the Georgia Sea Islands through the Breaching of the Silver Bluff Barrier and Dissection of the Ancestral Altamaha-Ogeechee Drainage. Abstract, 63rd Annual Meeting, Geological Society of America, Southeastern Section, April 10–11, 2014. 2 DeSalle, R., and I. Tattersall. 2014. Mr. Murray, you lose the bet.
    [Show full text]
  • The Relationship Between Trophic Level and Body Size in Fishes Depends on Functional Traits
    Ecological Monographs, 90(4), 2020, e01415 © 2020 by the Ecological Society of America The relationship between trophic level and body size in fishes depends on functional traits 1,3 2 1 FRIEDRICH W. K EPPELER , CARMEN G. MONTANA~ , AND KIRK O. WINEMILLER 1Department of Ecology and Conservation Biology, Texas A&M University, College Station, Texas USA 2Department of Biology, Stephen F. Austin State University, Nacogdoches, Texas USA Citation: Keppeler, F. W., C. G. Montana,~ and K. O. Winemiller. 2020. The relationship between trophic level and body size in fishes depends on functional traits. Ecological Monographs 90(4):e01415. 10.1002/ ecm.1415 Abstract. Predators typically are larger than their prey, and consequently, trophic level should increase with body size. Whereas this relationship has helped in developing predictions about food web structure and dynamics in mesocosms and simple communities, a trophic- level–body-size relationship may not exist for all kinds of communities or taxa, especially those with many non-carnivorous species. Moreover, functional traits associated with trophic level generally have not been considered. Herein, we examine the correlation between trophic level and body size in fishes and how this relationship may vary in relation to functional traits (body dimensions, mouth size and orientation, tooth shape, gill rakers, and gut length) and trophic guilds (carnivorous vs. non-carnivorous). We analyzed data from morphological measurements and dietary analyses performed on thousands of specimens from freshwater and estuarine habitats across three zoogeographic regions (Neartic, Neotropical, and Afrotropical). A posi- tive relationship between trophic level and body size was only found for carnivorous fishes.
    [Show full text]
  • Rehabilitation of Xenocharax Crassus (Teleostei: Distichodontidae), a Species Endemic to the Congo Basin in Central Africa
    347 Ichthyol. Explor. Freshwaters, Vol. 27, No. 4, pp. 347-354, 4 figs., 3 tabs., December 2016 © 2016 by Verlag Dr. Friedrich Pfeil, München, Germany – ISSN 0936-9902 Rehabilitation of Xenocharax crassus (Teleostei: Distichodontidae), a species endemic to the Congo basin in central Africa Armel Ibala Zamba*, **, Victor Mamonekene*, **, Emmanuel Vreven*** and Melanie L. J. Stiassny**** Xenocharax crassus Pellegrin, 1900, originally described from the Alima River (Congo basin, Republic of Congo) but synonymised with X. spilurus by Daget in 1960, is rehabilitated. Xenocharax crassus, a Congo basin endemic, is distinguished from X. spilurus, the latter found exclusively in basins of the Lower Guinean ichthyofaunal province, by the presence of a large black mark on the anterior part of the dorsal fin (versus absence), a small, round, black spot at the base of the caudal peduncle (versus a large ovoid spot covering the peduncle base), and a wider mouth (29-34 % HL vs. 24-29). For specimens of similar sizes, X. crassus has a shorter dorsal-adipose distance than X. spilurus. Furthermore, most X. crassus specimens have 6 supraneurals (frequency: 83 %) versus 7 (frequency: 79 %) in X. spilurus. With molecular data the species is readily distinguished from X. spilurus by 10 apomorphic, non-synonymous nucleotide transitions in the three sampled genetic markers (nd2, cyt-b, and myh6). A lectotype is designated for X. spilurus. Xenocharax crassus Pellegrin, 1900, originellement décrit de la rivière Alima (Bassin du Congo, République du Congo), puis mis en synonymie avec X. spilurus par Daget en 1960, est réhabilité. Xenocharax crassus, endémique du bassin du Congo, se distingue de X.
    [Show full text]
  • Diet Comparison in Three Species of Distichodus Müller & Troschel
    Available online at http://ajol.info/index.php/ijbcs Int. J. Biol. Chem. Sci. 4(1): 145-157, February 2010 ISSN 1991-8631 Original Paper http://indexmedicus.afro.who.int Diet comparison in three species of Distichodus Müller & Troschel, 1845 (Distichodontidae, Pisces) of Pool Malebo, Congo River (Democratic Republic of Congo) Victorine MBADU ZEBE 1* , Bekeli MBOMBA NSEU 1 and Jean-Claude MICHA 2 1 University of Kinshasa (UNIKIN), Faculty of Science, Kinshasa, R.D. Congo. 2 Facultés Universitaires Notre-Dame de la Paix (FUNDP) URBO, rue de Bruxelles, 61 B-5000 Namur, Belgique. * Corresponding author, E-mail: [email protected] : Tel: +24398846427 ABSTRACT The diet of Distichodus antonii , D. affinis and D. lusosso was studied in Malebo Pool (Congo River, Kinshasa, D.R. Congo) through the analysis of 396 stomach contents in relation to the size of fish and the hydrological seasons. The Index of preponderance (% Ip) was calculated. The analysis of the preponderance index (Ip) showed that D. antonii and D. affinis are herbivorous. D. antonii feeds mainly on leaves and stems of Echinochloa pyramidalis , while D. affinis consumes in addition roots and detritus. Periphyton was regularly found in the stomach contents of the three species. During the two hydrological seasons, a significant overlap of diet was observed between all the sizes of D. affinis and D. antonii. In D. lusosso, overlap of diet was not observed. Distichdus lusosso is generalist; its food is composed of detritus, animal preys such as fishes, shrimps, crabs, nymphs and larvae of insects, molluscs. This study shows that D. lusosso takes advantage of diversified food items compared with D.
    [Show full text]
  • Are Characiform Fishes Gondwanan in Origin? Insights from a Time-Scaled Molecular Phylogeny of the Citharinoidei (Ostariophysi: Characiformes)
    City University of New York (CUNY) CUNY Academic Works Publications and Research CUNY Graduate Center 2013 Are characiform Fishes Gondwanan in Origin? Insights from a Time-Scaled Molecular Phylogeny of the Citharinoidei (Ostariophysi: Characiformes) Jairo Arroyave CUNY Graduate Center John S. S. Denton American Museum of Natural History Melanie L. J. Stiassny American Museum of Natural History How does access to this work benefit ou?y Let us know! More information about this work at: https://academicworks.cuny.edu/gc_pubs/366 Discover additional works at: https://academicworks.cuny.edu This work is made publicly available by the City University of New York (CUNY). Contact: [email protected] Are characiform Fishes Gondwanan in Origin? Insights from a Time-Scaled Molecular Phylogeny of the Citharinoidei (Ostariophysi: Characiformes) Jairo Arroyave1,2*, John S. S. Denton1,3, Melanie L. J. Stiassny1 1 Department of Ichthyology, Division of Vertebrate Zoology, American Museum of Natural History, New York, New York, United States of America, 2 Department of Biology, the Graduate School and University Center, the City University of New York, New York, New York, United States of America, 3 Richard Gilder Graduate School, American Museum of Natural History, New York, New York, United States of America Abstract Fishes of the order Characiformes are a diverse and economically important teleost clade whose extant members are found exclusively in African and Neotropical freshwaters. Although their transatlantic distribution has been primarily attributed to the Early Cretaceous fragmentation of western Gondwana, vicariance has not been tested with temporal information beyond that contained in their fragmentary fossil record and a recent time-scaled phylogeny focused on the African family Alestidae.
    [Show full text]