New species of miniature fish from Marajó Island, Pará, Brazil, with comments on its relationships (Characiformes: Characidae

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Manoela M. F. Marinho

Full Text Available A new miniature species of the family Characidae from Marajó Island, Pará State, Brazil is described and assigned to the genus Tyttobrycon. The new species can be distinguished from its congeners primarily by having multicuspid teeth on jaws, and additionally by having the combination of 5-7 premaxillary teeth, dorsal fin only with scattered melanophores and the presence of an adipose fin.

Redescription of Hyphessobrycon flammeusMyers, 1924 (Ostariophysi: Characidae, a threatened species from Brazil

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Fernando R. Carvalho

Full Text Available One of the most gorgeous colored and endangered Hyphessobryconspecies, H. flammeus Myers, is redescribed. Diagnostic characters of the species are two vertically elongated humeral spots, no caudal peduncle blotch, 5-8 maxillary teeth, caudal fin hyaline, and longitudinal dark stripe of the body absent. Sexual dimorphism is present, with males being more colored than females and having bony hooks in the anal and pelvic fins, which are dark in their terminal portions. Comments about its occurrence in the upper rio Tietê drainage (upper rio Paraná basin, its conservation status, and the phylogenetic position into Characidae context are also presented.

Desenvolvimento e diferenciação dos ovócitos de pacu, Piaractus mesopotamicus (Holmberg, 1887 (Osteichthyes, Characidae Oocyte development and differentiation in pacu, Piaractus mesopotamicus (Holmberg, 1887 (Osteichthyes, Characidae

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Massuka Yamane Narahara

2002-05-01

Full Text Available O objetivo deste trabalho foi o de esclarecer dúvidas referentes ao desenvolvimento e à diferenciação dos ovócitos de Piaractus mesopotamicus (Osteichthyes, Characidae, ultra-estruturalmente, acompanhando as transformações que ocorreram durante o processo de ovogênese tais como: formação e acúmulo de várias organelas, inclusões nucleares e/ou citoplasmáticas e a camada ou envelope folicular. Na fase de crescimento primário são evidentes os corpúsculos de Balbiani, mas não são claros seus papéis. Estão presentes, também, as peculiares estruturas lamelares. A segunda fase, a de crescimento secundário, caracteriza-se, inicialmente, pela formação de alvéolos corticais. A seguir, os grânulos de vitelo protéico formam-se na região periférica com abundância de mitocôndrias e ribossomos. Mudanças no epitélio folicular (granulosa são descritas concomitantemente com a formação da zona radiata, que constitui o envoltório folicular (envelope.This work aim is to clarify doubts about the Piaractus mesopotamicus (Osteichthyes, Characidae oocyte ultrastructural development and differentiation, following the transformations during the ovogenic processes, such as formation and accumulation of various organelles, nucleolar and/or citoplasmic inclusions, and follicular wall (envelope. During the primary growth phase, Balbiani corpuscles are evident, but their role is not clear. The peculiar lamellae structures are also present. The second phase (secondary growth is initially characterized by cortical alveolus formation. After that, protein yolk granules appear in the peripherical regions, where mitochondria and ribosomes are abundant. Changes in the follicle epitelium (granulosa are described together with the radiate zone formation, which constitutes the follicular envelope.

Feeding and morphological analysis of the digestive tract of four species of fish (Astyanax altiparanae, Parauchenipterus galeatus, Serrasalmus marginatus and Hoplias aff. malabaricus from the upper Paraná River floodplain, Brazil

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D. Peretti

Full Text Available The present study is inspired by the great wealth of species exhibited by the ichthiofauna. Not only concepts and techniques of ecology deserve attention, but also knowledge in other biological areas, such as zoology and anatomy, are necessary. The intention of the present work is to discover the morphology of fish through the study of the digestive tract morphology, associating it to diet data, in order to better understand the biology of four fish species of the upper Paraná River floodplain. The samples were collected quarterly in the year 2000 with gillnets of different meshes. The stomach content was analyzed under a stereoscopic microscope and the frequencies of occurrence (FO and volumetric (FV and the alimentary index (IAi were calculated. Various morphologic characteristics were analyzed and schematized using a light chamber. The species were grouped into two trophic guilds - insectivores (Astyanax altiparanae and Parauchenipterus galeatus and piscivores (Serrasalmus marginatus and Hoplias aff. malabaricus. The first two, although consumers of insects, preyed on different alimentary groups, notably Hymenoptera in the case of A. altiparanae and Coleoptera in the case of P. galeatus. Serrasalmus marginatus and H. aff. malabaricus consumed mainly fishes. However, only pieces of prey were usually found in the stomach content of the first species, whereas whole fishes were found in the stomach content of the second. Astyanax altiparanae exhibited characteristics that allowed it to obtain food in several compartments of the water column. Similarly P. galeatus consumed food resources that were available in all aquatic compartments, although the abilities to capture, to manipulate and to absorb food differed, as shown by the importance of teeth plates and pharyngeal teeth. Serrasalmus marginatus and H. aff. malabaricus, although resembling each other in many aspects of the digestive tract morphology, differed in the strategies used to capture

Patterns of food resource use by two congeneric species of piranhas (Serrasalmus) on the Upper Paraná River floodplain.

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Agostinho, C S; Hahn, N S; Marques, E E

2003-05-01

Serrasalmus marginatus invaded the Upper Paraná River after construction of the Itaipu Dam in November 1982. This was followed by a reduction in abundance of the native species S. spilopleura. Analysis of the pattern of food resource use revealed that both species employ the same feeding strategy, eating mainly fish (whole fish or muscle fragments) and fins bitten off their prey. The diurnal activity period and the feeding rhythm were better-defined in S. marginatus. For young individuals of both species, food was taken in a significantly discontinuous manner (F = 2.83; p < 0.05 and F = 13.25; p < 0.05), with a peak at 4 p.m. Ontogenetic differences in diet, the strong feeding overlap of larger individuals of S. marginatus and smaller individuals of S. spilopleura, and the aggressiveness of S. marginatus in establishing feeding territories may have contributed to the success of the invading species.

Patterns of food resource use by two congeneric species of piranhas (Serrasalmus on the upper Paraná river floodplain

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C. S. Agostinho

Full Text Available Serrasalmus marginatus invaded the Upper Paraná River after construction of the Itaipu Dam in November 1982. This was followed by a reduction in abundance of the native species S. spilopleura. Analysis of the pattern of food resource use revealed that both species employ the same feeding strategy, eating mainly fish (whole fish or muscle fragments and fins bitten off their prey. The diurnal activity period and the feeding rhythm were better-defined in S. marginatus. For young individuals of both species, food was taken in a significantly discontinuous manner (F = 2.83; p < 0.05 and F = 13.25; p < 0.05, with a peak at 4 p.m. Ontogenetic differences in diet, the strong feeding overlap of larger individuals of S. marginatus and smaller individuals of S. spilopleura, and the aggressiveness of S. marginatus in establishing feeding territories may have contributed to the success of the invading species.

Patterns of food resource use by two congeneric species of piranhas (Serrasalmus on the upper Paraná river floodplain

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Agostinho C. S.

2003-01-01

Full Text Available Serrasalmus marginatus invaded the Upper Paraná River after construction of the Itaipu Dam in November 1982. This was followed by a reduction in abundance of the native species S. spilopleura. Analysis of the pattern of food resource use revealed that both species employ the same feeding strategy, eating mainly fish (whole fish or muscle fragments and fins bitten off their prey. The diurnal activity period and the feeding rhythm were better-defined in S. marginatus. For young individuals of both species, food was taken in a significantly discontinuous manner (F = 2.83; p < 0.05 and F = 13.25; p < 0.05, with a peak at 4 p.m. Ontogenetic differences in diet, the strong feeding overlap of larger individuals of S. marginatus and smaller individuals of S. spilopleura, and the aggressiveness of S. marginatus in establishing feeding territories may have contributed to the success of the invading species.

NUTRIÇÃO MATERNA: EFEITOS DA PROTEÍNA DE PESCADO DE ÁGUA DOCE (Serrasalmus nattereri NA COMPOSIÇÃO DA CARCAÇA DE RATAS GESTANTES

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Ely Carvalho Vasconcellos MOURA

2009-07-01

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RESUMO: Estudamos os efeitos da proteína de pescado (Serrasalmus nattereri (piranha de água doce, como única fonte protéica, em nível de 18% nas rações, sobre os níveis de lipídios e de nitrogênio e a retenção do nitrogênio pela carcaça de ratas gestantes. Foram utilizadas ratas virgens “Wistar”, divididas após o acasalamento, nos grupos: Gestante Controle Cesárea (Gces (Caseína e Gestante Pescado Cesárea (Gpces. Dois grupos não gestantes (NGC e NGP foram formados a fim de separarmos os efeitos da gestação. O grupo zero (GO foi sacrificado no 1º dia e aos demais aos 21 dias de experimentação. Pelos resultados concluímos que: a gestação conduziu a uma maior percentagem de gordura na carcaça de GCes e GPces, em relação à NG. Ambas proteínas ensaiadas não conduziram a variações quanto à concentração de nitrogênio nas gestantes. O conteúdo total de nitrogênio foi menor nas gestantes, em relação aos seus pares NG. A mobilização do nitrogênio foi maior na carcaça das gestantes; a gestação propiciou menor retenção na quantidade de nitrogênio, sendo que as proteínas ensaiadas não diferiam entre si. A proteína do pescado propiciou adequada mobilização do nitrogênio com a finalidade de garantir o desenvolvimento fetal. PALAVRAS-CHAVE: Gestantes; proteína da farinha de pescado; lipídios e nitrogênio em carcaça de ratas; Serrasalmus nattereri; piranha.

Una nueva especie ecuatoriana del género de peces andinos Grundulus (Characiformes: Characidae

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César Román-Valencia

2005-09-01

Full Text Available Se describe Grundulus quitoensis nueva especie (Characiformes, Characidae proveniente de las Lagunas El Voladero reserva biológica El Angel al norte de Ecuador. El nuevo taxon se distingue de las demás especies por el menor número de radios simples en la aleta anal (tres vs. cuatro a cinco y en las aletas pectorales (uno vs. dos a tres, por el mayor número de dientes en cada dentario (12- 14 vs. 8-10, perfil ventral posterior a la cintura pectoral hasta el origen de la aleta anal plano (vs. curvo, el segundo infraorbital es tres veces más grande que el primero (vs. dos veces más grande, el tercer infraorbital está separado del preopérculo (vs. en contacto con la superficie del preopérculo, dentario presenta cuatro pequeñas fenestras en el margen infero-lateral (vs. uno a dos, el premaxilar presenta un proceso lateral largo (vs. corto, maxilar con dos muescas en la superficie infero-lateral (vs. maxilar con una muesca en la superficie inferolateral.A new Ecuadorian species of the Andean fish genus Grundulus (Characiformes: Characidae. The new species Grundulus quitoensis is described from El Voladero Lake, El Angel Biological Reserve, Northern Ecuador. The new taxon can be distinguished from all congeners by the following characters, respectively: a low number of unbranched rays in the anal fin (three vs. four-five and in pectoral fins (on vs. two - three, a higher number of dentary teeth (12-14 vs. 8-10, a second infraorbital about three times larger than the first (vs. about two times larger, a third infraorbital which is not in contact with the preopercle (vs. in contact with preopercle, the presence of four small fenestrae in the infero-lateral bone dentary (vs. one - two; and a premaxilla which presents a long lateral process (vs. short, a maxilla with two notches in the infero-lateral surface (vs. one notch in the infero-lateral surface. Rev. Biol. Trop. 53(3-4: 537-544. Epub 2005 Oct 3.

Alimentação de Serrasalmus maculatus (Kner, 1858 (Characiformes; Serrasalmidae no trecho inferior bacia do rio Sorocaba, São Paulo, Brasil - DOI: 10.4025/actascibiolsci.v30i3.5011 Feeding of Serrasalmus maculatus (Kner, 1858 (Characiformes; Serrasalmidae in the Sorocaba river, São Paulo State, Brazil - DOI: 10.4025/actascibiolsci.v30i3.5011

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Leandro Muller Gomiero

2008-10-01

Full Text Available O objetivo foi abordar a alimentação de Serrasalmus maculatus. A captura dos exemplares foi realizada com a utilização de redes de emalhar de malhas entre 3 a 8 cm entre nós opostos, totalizando 100 m. Foram coletados 107 indivíduos com comprimento-padrão variando entre 62 e 210 mm, representados principalmente por fêmeas e imaturos. Nenhum indivíduo foi capturado em temperaturas inferiores a 21ºC. Ocorreram quatro categorias de itens alimentares nos estômagos analisados, a saber: pedaços de musculatura de peixe, partes de nadadeiras, fragmentos de vegetais e insetos. Foram feitas comparações entre as classes de comprimento mostrando que ocorrem diferenças significativas nos itens alimentares consumidos na maioria dessas classes. A partir da classe de 165 mm, observaram-se apenas os itens musculatura e vegetais. A disponibilidade dos itens no ambiente e a amplitude de comprimento dos exemplares coletados podem estar mascarando a maior diferenciação ontogenética na dieta desta espécie.The aim of this study was to discuss aspects of the diet of Serrasalmus maculatus. Fish were collected using gill nets, whose lengths measured 100 m and mesh diameters varied from 3 to 8 cm. A total of 107 individuals were collected. Their length varied from 62 to 210 mm. They were mainly represented by female and immature individuals. No individual was caught in temperatures below 21ºC. Four feeding item categories were observed: fish muscle pieces, parts of fish fins, plant fragments, and insects. Comparisons made among individual length classes revealed some significant differences within stomach consumed contents. Individuals whose length exceeded 165 mm consumed only parts of fish muscles and plants. The food availability in the environment and the class lengths amplitude may, however, have influenced the results, in which ontogenetic differences should not be precisely observed.

Protocheirodon, a new genus of Characidae (Teleostei: Characiformes with the redescription of the poorly known Protocheirodon pi

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Richard P. Vari

Full Text Available ABSTRACT Protocheirodon, a new genus of the Characidae, is proposed to include a species previously assigned to Leptagoniates . This action is supported by molecular and morphological phylogenetic hypotheses that place Protocheirodon pi as the sister group of the remaining tribes in the Cheirodontinae versus the traditional assignment of the species to the Aphyocharacinae. The phylogenetic position of Protocheirodon is recognized as a new tribe, the Protocheirodontini. Protocheirodon pi , originally described based on a small number of specimens from a single location in the río Mamoré basin in the southwestern Amazon, is redescribed on the basis of larger series of specimens from the western and central portions of the Amazon basin.

UNE NOUVELLE ESPÈCE DE TOMETES (TELEOSTEI : CHARACIDAE : SERRASALMINAE DU BOUCLIER GUYANAIS, TOMETES LEBAILI N. SP.

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JÉGU M.

2002-01-01

Full Text Available Tometes lebaili n. sp. diffère de Tometes trilobatus Valenciennes, 1850, par la position de la bouche, oblique et dirigée vers le haut. T. lebaili présente 7 à 8 dents à la série labiale du dentaire contre 5 chez T. trilobatus. T. trilobatus, citée des rapides de l’Araguari (Amapá, Brésil à l’Oyapock (Guyane française, est remplacée plus à l’ouest par T. lebaili n. sp., décrite de la Mana (Guyane fr. au Commewine (Surinam et peut-être présente dans le Sinnamary. La taille maximale observée pour T. lebaili est de 512 mm LS.

Morfología de las especies de Hyphessobrycon (Characiformes: Characidae, grupo heterorhabdus, en Colombia

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Carlos A. García-Alzate

2011-06-01

Full Text Available El género Hyphessobrycon incluye dieciocho especies reportadas para Colombia de las cuales 13 son miembros del grupo heterorhabdus; con las mismas, se realizó un análisis morfogeométrico por medio del Método de Cerchas (Box Truss y Láminas Delgadas (TPS. Se usaron 13 hitos homólogos tipo I y tres tipo II. El resultado del análisis cluster, llevado a cabo con cada una de las metodologías indicó que estas especies están representadas en dos grandes grupos: robustas y delgadas. Las deformaciones parciales, los componentes uniformes, no uniformes, Warps principales y Warps parciales describieron cambios de la forma relacionados con la profundidad del cuerpo e involucraron desplazamientos relativos del esqueleto apendicular y de la región cefálica. Todas las especies se caracterizan por presentar crecimiento alométrico excepto Hyphessobrycon mavro con isometría entre los hitos 6-7. Se plantean dos nuevas medidas discriminantes (hocico-supraoccipital y supraoccipital-aleta pélvica para las especies del grupo.Morphology of the species Hyphessobrycon, heterorhabdus group (Characiformes: Characidae in Colombia. Hyphessobrycon is the most numerous and morphologically complex genus of Characidae, and includes 18 species reported for Colombia, from which thirteen belong to the heterorhabdus-group different methods have been proposed for species identification within this genus. This study used these species to undertake a morphogeometric analysis by the Box Truss and Thin Plate Splin (TPS methods; 13 homologous landmarks type I and three type II were used. The result of cluster analysis indicated that these species are represented by two big groups: robust and thin. The uniform and non uniform components, and the principal warps (WP and partial warps (Wparc, described the shape changes related to body depth, involving relative displacements of the appendicular skeleton and the cephalic region. All species were characterized by allometric

Coptobrycon bilineatus (Ellis, 1911 (Characiformes: Characidae: redescription and comments on its phylogenetic relationships

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Francisco Langeani

Full Text Available Coptobrycon bilineatus (Ellis, 1911 is redescribed on the basis of specimens from the District of Paranapiacaba, Municipality of Santo André, upper rio Tietê, and additional ones recently collected in a small coastal river system of Serra do Mar, very near the headwaters of the rio Tietê. The genus was compared to other Characidae lacking a supraorbital, and it seems to be more phylogenetically related to Grundulus based on the possession of various putative apomorphic character states related to: the absence of a rhinosphenoid and fourth, fifth (sometimes and sixth infraorbitals; nasal pores separated; nares with up to six nasal lamellae; cephalic laterosensory system poorly developed on supraorbital and infraorbital series; and a globose scapula. Furthermore, Coptobrycon and Grundulus are characterized by the absence of the adipose fin, of the supraorbital laterosensory series on the parietal, and of the humeral spot, and by the reduction of lateral musculature in front of the first pleural rib and between the first and second pleural ribs. Biogeographic comments are also provided.

Redescripción de Hemibrycon orcesi Böhlke, 1958 y H. polyodon (Gunther, 1864 (Teleostei, Characidae, incluye clave para las especies de Hemibrycon en Ecuador

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Román-Valencia, C.

2007-12-01

Full Text Available Redescription of Hemibrycon orcesi Böhlke, 1958 and H. polyodon (Günther, 1864 (Pisces, Characidae, with a key for the species of Hemibrycon from Ecuador. Hemibrycon orcesi is readily distinguished from its congeners by its 13 to 16 teeth on maxilla, base of caudal fin scaled, 34 to 36 scales on lateral line with pores and 17 to 18 branched anal fin rays. H. polyodon is distinguished from its congeners by simple and branched dorsal fin rays of equal length and shape of humeral spot.

Frugivory by the fish Brycon hilarii (Characidae) in western Brazil

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Reys, Paula; Sabino, José; Galetti, Mauro

2009-01-01

Frugivory and seed dispersal have been poorly studied in Neotropical freshwater fishes. We studied frugivory and seed dispersal by the piraputanga fish ( Brycon hilarii, Characidae) in the Formoso River, Bonito, western Brazil. We examined the stomach contents of 87 fish and found the diet of piraputanga consisted of 24% animal prey (arthropods, snails, and vertebrates), 31% seeds/fruits and 45% other plant material (algae/macrophytes/leaves/flowers). The piraputangas fed on 12 fruit species, and were considered as seed dispersers of eight species. Fruits with soft seeds larger than 10 mm were triturated, but all species with small seeds (e.g. Ficus, Psidium) and one species with large hard seed ( Chrysophyllum gonocarpum) were dispersed. Piraputangas eat more fruits in the dry season just before the migration, but not during the spawning season. Fish length had a positive relation with the presence of fruits in their guts. The gallery forest of the Formoso River apparently does not have any plant species that depend exclusively on B. hilarii for seed dispersal because all fruit species are also dispersed by birds and mammals. Based on seed size and husk hardness of the riparian plant community of Formoso River, however, the piraputangas may potentially disperse at least 50% of the riparian fleshy fruit species and may be particularly important for long-distance dispersal. Therefore, overfishing or other anthropogenic disturbances to the populations of piraputanga may have negative consequences for the riparian forests in this region.

Feeding ecology of stream-dwelling Characidae (Osteichthyes: Characiformes from the upper Tocantins River, Brazil

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Maíra Moraes

2013-12-01

Full Text Available In this contribution we studied the trophic ecology of four Characidae species from the Cavalo Stream, upper Tocantins River, considering diet overlap and trophic niche breadth. The diet of the four species was composed of adult and immature insects, both autochthonous and allochthonous in origin. Autochthonous items dominated the diet of Moenkhausia dichroura (Kner, 1858, Bryconamericus sp., and Creagrutus atrisignum Myers, 1917. By contrast, allochthonous items were dominant in the diet of Astyanax bimaculatus (Linnaeus, 1758. Trophic niche breadth varied among species, with the highest value recorded for M. dichroura (0.48, followed by Bryconamericus sp. (0.39, A. bimaculatus (0.33 and C. atrisignum (0.29. Similarity analysis revealed two groups with different patterns of food preference. The first group was composed of insectivorous and the second by omnivorous species. The overlap in food items consumed by the four species studied was high. We suggest that resources are not limited in this stream and that competition might not be regulating these populations. This is one more case corroborating the general pattern registered for Tropical environments, where resource partitioning and specialization are responsible by the organization of fish communities.

Non-seasonal reproduction in inseminating species of Mimagoniates (Characidae, Characiformes from southern Brazil

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Vinicius Renner Lampert

2018-03-01

Full Text Available Abstract Some aspects of reproduction in two species of Mimagoniates, M. microlepis (Steindachner 1877 and M. rheocharis Menezes & Weitzman 1990 are herein described. Samples were taken monthly from January 1998 to February 1999 in two streams in the locality of Maquiné, Rio Grande do Sul, Brazil. Results from the analysis of hundreds of specimens of M. microlepis and M. rheocharis in two investigated sites indicated mature specimens and peaks of the gonadosomatic index (GSI along the year. There was a negative and significant correlation between M. microlepis male’s GSI and water temperature. Females of the latter species and both sexes of M. rheocharis, in turn, showed no correlation with any of the tested parameters (relative stomach weight, day length, rainfall. Absolute and relative fecundity are lower than in externally fertilized species of Characidae. Maximum oocyte length was 1.14 mm for M. microlepis and 1.02 mm for M. rheocharis and both species were characterized as total spawners based on the type of oocyte development estimated through oocyte size analysis. Features like non-seasonal reproductive period, low fecundity, and insemination may indicate adaptive advantages, which may enhance the chance of survival even with low energetic investment and improved fertilization.

A new species of Cacatuocotyle (Monogenea, Dactylogyridae) parasitizing Astyanax spp. (Characiformes, Characidae) from Brazil, including molecular data and a key to species identification.

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Zago, Aline Cristina; Franceschini, Lidiane; Müller, Maria Isabel; Silva, Reinaldo José da

2018-06-26

The present study describes Cacatuocotyle papilionis n. sp. (Monogenea, Dactylogyridae) from the skin of the characid fishes Astyanax lacustris (Lütken, 1875) (=Astyanax altiparanae Garutti & Britski, 2000) and Astyanax fasciatus (Cuvier, 1819) (Characiformes, Characidae) from the Southeast of Brazil, supported by morphological and molecular data. The new species differs from all congeners, mainly due to the morphology of the ventral bar (resembling a butterfly), accessory piece, and the number of rings of the male copulatory organ (MCO), comprising a coiled tube with 4.5-5.5 counterclockwise rings. The first molecular data for this monogenean genus is provided in this study, using the partial sequences of the ribosomal gene (28S), as well as providing an identification key to the species.

Eficácia do diflubenzuron no controle de Dolops carvalhoi (Crustacea: Branchiura em jovens pacus Piaractus mesopotamicus (Osteichthyes: Characidae naturalmente infectados - DOI: 10.4025/actascianimsci.v27i2.1235 Diflubenzuron effectiveness in Dolops carvalhoi (Crustacea: Branchiura control in juvenile pacus Piaractus mesopotamicus (Osteichthyes: Characidae naturally infected - DOI: 10.4025/actascianimsci.v27i2.1235

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Julieta Rodini Engrácia de Moraes

2005-03-01

Full Text Available Neste ensaio, avaliou-se a eficácia terapêutica do diflubenzuron contra o crustáceo Dolops carvalhoi (Crustacea: Branchiura em pacus Piaractus mesopotamicus Holmberg 1887 (Osteichthyes: Characidae naturalmente infestados. A droga foi aplicada três vezes na concentração de 2,0 mg/L de água, na forma de banhos com trinta minutos de duração e intervalo de 24 horas. Um grupo controle foi submetido ao mesmo procedimento, sem a adição do fármaco à água. A avaliação parasitológica revelou que a eficácia da droga foi de 97,2%. No grupo tratado houve redução da glicemia, aumento da quantidade de eritrócitos, redução do percentual de células granulocíticas especiais e aumento da quantidade de trombócitos circulantes coincidentes com a eliminação dos parasitos, quando comparado ao grupo controle. Os resultados indicam que ocorreu melhora marcante na saúde dos peixesThis research evaluated the therapeutic efficacy of diflubenzuron against Dolops carvalhoi (Crustacean: Branchiura in Piaractus mesopotamicus (Osteichthyes: Characidae naturally infested. The drug was applied three times, at a dose of 2.0 mg/L of water, in the form of baths within thirty minutes and an interval of 24 hours. A control group was submitted to the same procedure, but without pharmaco in the water. The parasitological evaluation showed that the drug effectiveness was 97.2%. In the treated group there were glycemia reduction, increase in the erythrocyte number, decrease in the percentage of special granulocytic cells and increase in the number of circulant trombocytes similar to the parasites elimination when compared to the control group. Results showed an important improvement in fish health

Alterações hematológicas e histopatológicas em pacu, Piaractus mesopotamicus Holmberg, 1887 (Osteichthyes, Characidae, Hematological and histopathological alteration in pacu Piaractus mesopotamicus Holmberg, 1887 (Osteichthyes, Characidae after treatment with copper sulphate (CuSO4

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Flávio Ruas de Moraes

2002-05-01

Full Text Available Este trabalho avaliou os valores hematológicos e glicêmicos e histopatologia de Piaractus mesopotamicus (Osteichthyes, Characidae infectados com Monogenea Anacanthorus penilabiatus Boeger, Husak & Martins, 1995 (Dactylogyridae após tratamento com 0,50 mg/L e 1,00 mg/L de sulfato de cobre (CuSO4. A eficiência da droga sobre as infecções com Monogenea foi observada no primeiro dia após administração mas não após 8, 15 ou 30 dias do tratamento. As análises histopatológicas mostraram hiperplasia do epitélio e alterações circulatórias nas brânquias. No primeiro dia após tratamento, foram observadas alterações significativas (P4 mostraram redução da taxa de hemoglobina e do percentual de neutrófilos. No 8o dia do tratamento a dose de 1,00 mg/L provocou aumento da glicemia mas redução no percentual de linfócitos quando comparada com 0,50 mg/L. No 15o dia após tratamento com 1,00 mg/L os valores médios do volume corpuscular médio e o percentual de células granulocíticas especiais (C.G.E. decresceram mas o número de leucócitos totais aumentaram. No 30o dia após tratamento com 0,50 mg/L de sulfato de cobre houve aumento de C.G.E. e no tratamento com 1,00 mg/L o aumento foi de linfócitos.This paper evaluated the haematological and glycaemic parameters in Piaractus mesopotamicus (Osteichthyes, Characidae infected with Monogenea Anacanthorus penilabiatus Boeger, Husak & Martins, 1995 (Dactylogyridae after treatment with 0.50 mg/L and 1.00 mg/L of copper sulphate (CuSO4. The efficacy of the CuSO4 was observed in the first day after administration but not after eight, fifteen or thirty days. The histopathological analyses showed hyperplasia of the epithelium and circulatory changes in the gills. In the first day after treatment significant changes (Pth day. Fifteen days after 1.00 mg/L treatment, values of mean corpuscular volume (MCV and special granulocitic cells (S.G.C. percentage decreased. Nevertheless, increase of

Esterase-D and chromosome patterns in Central Amazon piranha (Serrasalmus rhombeus Linnaeus, 1766 from Lake Catalão

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Aylton Saturnino Teixeira

2006-01-01

Full Text Available This study presents additional genetic data on piranha (Serrasalmus rhombeus Linnaeus, 1766 complex previously diagnosed due to the presence of distinct cytotypes 2n = 58 and 2n = 60. Three esterase-D enzyme loci (Est-D1, Est-D2 and Est-D3 were examined and complemented with chromosomal data from 66 piranha specimens collected from Lake Catalão. For all specimens the Est-D1 and Est-D2 loci were monomorphic. In contrast, the Est-D3 locus was polymorphic with genotypes and alleles being differentially distributed in the previously described cytotypes and served as the basis for detecting a new cytotype (2n = 60 B. In cytotype 2n = 58 the Est-D3 locus was also polymorphic and presented Mendelian allelic segregation with four genotypes (Est-D3(11, Est-D3(12, Est-D3(22 and Est-D3(33 out of six theoretically possible genotypes, presumably encoded by alleles Est-D3¹ (frequency = 0.237, EsT-D3² (0.710 and Est-D3³ (0.053. A Chi-squared (chi2 test for Hardy-Weinberg equilibrium was applied to the Est-D3 locus and revealed a genetic unbalance in cytotype 2n = 58, indicating the probable existence in the surveyed area of different stocks for that karyotypic structure. A silent null allele (Est-D3(0 with a high frequency (0.959 occurred exclusively in the 2n = 60 cytotype. On the other hand, the new cytotype 2n = 60 B described here for the first time was monomorphic for the presumably fixed Est-D3³ allele. The data as a whole should contribute to the better understanding the rhombeus complex taxonomic status definition in the Central Amazon.

Oocyte adhesiveness and embryonic development of Astyanax bimaculatus (Linnaeus, 1758) (Pisces: Characidae).

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Weber, André Alberto; Arantes, Fábio Pereira; Sato, Yoshimi; Rizzo, Elizete; Bazzoli, Nilo

2013-05-01

This study shows for the first time the presence of a jelly coat on oocytes of neotropical Characiformes fish. This structure could be responsible for the adhesiveness of Astyanax bimaculatus oocytes, a species widely distributed in South America including in the São Francisco River basin in Brazil. Adult specimens of A. bimaculatus were submitted to artificial reproduction in order to analyse the egg morphology and embryonic development. The eggs were fertilised and kept in incubators with a water temperature of 24°C so that embryogenesis could be monitored. Ovulated and unfertilised oocytes were also collected and submitted to routine histological techniques. Astyanax bimaculatus oocytes were found to be spherical, yellowish, and covered by a thin jelly coat with a slightly adhesive surface. The mean oocyte diameter was 1.03 ± 0.03 mm, the perivitelline space was 0.21 ± 0.02 mm and the jelly coat's thickness was 0.04 ± 0.01 mm. Positive periodic acid-Schiff (PAS) stain and Alcian blue stain pH 2.5 indicated the presence of neutral glycoproteins, and carboxylated acid glycoconjugates on the jelly coat that formed mucosubstances that may be associated with egg adhesiveness. At a water temperature of 24°C, blastopore closure and hatching occurred at 5 h and 17 h after fertilisation, respectively. The results of this study provide essential information for phylogenetic studies and for a better understanding of the reproductive strategy of A. bimaculatus, currently included in the incertae sedis group of the Characidae family due to the lack of monophyly among the families of the group.

Morfogeometría de los peces del género Hyphessobrycon (Characiformes: Characidae, grupo heterorhabdus, en Venezuela

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Carlos A García-Alzate

2010-09-01

Full Text Available El género Hyphessobrycon es uno de los más numerosos y morfológicamente complejos de la familia Characidae, incluye 122 especies válidas, de las cuales 17 están en Venezuela. El objetivo del presente estudio fue realizar un análisis morfogeométrico comparado entre las especies del género Hyphessobrycon grupo heterorhabdus; 310 ejemplares fueron fotografiados y analizados mediante el método de cerchas (Box Truss, por medio de la combinación de 16 hitos homólogos y un total de 28 mediciones. El análisis de componentes principales (ACP indicó que las diferencias entre especies están relacionadas con distancia hocico-supraoccipital (81.7% y supraoccipital-base aleta pectoral (11.87%; todas las especies tienen crecimiento alométrico, excepto Hyphessobrycon tuyensis, que presento isometría en la cercha I; las deformaciones parciales describen diferencias en la forma relacionadas con la región cefálica y la profundidad del cuerpo. Se plantea que la asociación de formas está relacionada con la filogenia y biogeografía de las especies.

Ichthyouris voltagrandensis n.sp. (Nematoda: Pharyngodonidae) from Myleus tiete Eigenmann & Norris, 1900 (Osteichthyes: Characidae) in the Volta Grande Reservoir, MG, Brazil.

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Martins, M L; Yoshitoshi, E R; Umekita, H

2001-05-01

The present work studied helminth parasites of "pacu-manteiga", Myleus tiete (Osteichthyes: Characidae) from Volta Grande Reservoir, MG, Brazil. Fishes with 142.6 +/- 24.7 g weight and 17.3 +/- 1.0 cm total length were collected. Five out six analysed fish (prevalence 83.3%) were parasitized in the intestine with an average of 535.6 +/- 334.6 oxyurid nematodes per fish. The helminth was identified as Ichthyouris voltagrandensis n.sp. (Nematoda: Pharyngodonidae). It differs from I. brasiliensis (Moravec et al., 1992a) by the absence of lateral alae, higher measures of tail and caudal alae of males, esophageal isthmus length, distance of excretory pore from anterior end and spicule length. In addition, eggs were provided by two long filaments in just one pole and by the first time the authors observed flagellate spermatozoa from dissected males. The authors exposes comparative table of measures of the five described species of the genus Ichthyouris.

Molecular cytogenetics and characterization of a ZZ/ZW sex chromosome system in Triportheus nematurus (Characiformes, Characidae).

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Diniz, Débora; Moreira-Filho, Orlando; Bertollo, Luiz Antonio Carlos

2008-05-01

Chromosomes of Triportheus nematurus, a fish species from family Characidae, were analyzed in order to establish the conventional karyotype, location of C-band positive heterochromatin, Ag-NORs, GC- and AT-rich sites, and mapping of 18S and 5S rDNA with fluorescence in situ hybridization (FISH). The diploid number found was 2n = 52 chromosomes in both males and females. However, the females presented a pair of differentiated heteromorphic chromosomes, characterizing a ZZ/ZW sex chromosome system. The Z chromosome was metacentric and the largest one in the karyotype, bearing C-positive heterochromatin at pericentromeric and telomeric regions. The W chromosome was middle-sized submetacentric, appearing mostly heterochromatic after C-banding and presenting heterogeneous heterochromatin composed of GC- and AT-rich regions revealed by fluorochrome staining. Ag-NORs were also GC-rich and surrounded by heterochromatic regions, being located at the secondary constriction on the short arms of the second chromosome pair, in agreement with 18S rDNA sites detected with FISH. The 18S and 5S rDNA were aligned in tandem, representing an uncommon situation in fishes. The results obtained reinforce the basal condition of the ZZ/ZW sex system in the genus Triportheus, probably arisen prior to speciation in the group.

Markiana nigripinnis (Perugia, 1891 as a putative member of the subfamily Stevardiinae (Characiformes: Characidae: spermatic evidence

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Clarianna Martins Baicere-Silva

Full Text Available The genus Markiana was until recently recognized as incertae sedis in the family Characidae, even though alternative placements for this genus have been advanced since its original description. More recently, it was hypothesized that Markiana nigripinnis is part of a clade informally named the Astyanax clade, indicating the putative close relationship of Markiana with the genus Astyanax. Examination of sperm ultrastructure of representatives of Astyanax and M. nigripinnis shows no evidence for this hypothesized close relationship. Rather, the spermatozoa of M. nigripinnis share characters found in spermatozoa of the non-inseminating members of the subfamily Stevardiinae, such as an angle of nuclear rotation equal to 85º resulting in a lateral position of the double nuclear fossa and flagellum. As with the non-inseminating Stevardiinae, sperm nuclei are also slightly elongate toward the flagellum, the proximal centriole is partially inside the nuclear fossa and anterior and oblique to the distal centriole, and the midpiece is short and strongly asymmetric. Additionally, M. nigripinnis shares with the other members of the Stevardiinae the presence of only four teeth in the inner row of the premaxillary and a short triangular ectopterygoid, which is never more than twice the length of the palatine.

An outbreak of myxozoan parasites in farmed freshwater fish Colossoma macropomum (Cuvier, 1818 (Characidae, Serrasalminae in the Amazon region, Brazil

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Marcela Videira

2016-05-01

Full Text Available The tambaqui (Colossoma macropomum is a native fish species that is farmed most frequently and in the largest quantities throughout Brazil. The high production of this species from fish farms has contributed to the occurrence of emerging parasites, which may compromise fish health and productivity. In a batch of 2500 tambaqui fry acquired for experimental farming procedures in Brazil, a mortality rate of 80% was observed, with the fish swimming erratically and gasping for air at the water surface. From among the specimens that were still alive, 60 individuals were selected at random. Organs or fragments of organs containing lesions and/or cysts were examined under an optical microscope to investigate for the presence of parasitic spores. Of the 60 specimens of tambaqui analyzed, 83.3% were found to be infected in different organs, such as the gills, liver, and gallbladder with myxosporidian species belonging to four genera, namely, Myxobolus, Ellipsomyxa, Henneguya and Thelohanellus. The parasite with the greatest prevalence was Myxobolus sp., located in the gills (70%, followed by Henneguya sp. in the gills region (68.3%, Myxobolus sp. in the liver (63.3%, Thelohanellus sp. in the liver (58.3%, and Ellipsomyxa in the gallbladder (50%. This is the first report of parasitic infection caused by the genera Ellipsomyxa and Thelohanellus in C. macropomum. The present study reported the second incidence of the occurrence of the genus Thelohanellus in South America. This study suggested that the mortality among C. macropomum specimens was caused by the outbreak of myxosporidians. Keywords: Amazon, Tambaqui, Parasite, Myxozoa, Myxosporidians

Alimentação e ecomorfologia de duas espécies de piranhas (Characiformes: Characidae do lago de Viana, estado do Maranhão, Brasil Feeding and ecomorphology of two species of piranhas (Characiformes: Characidae from the Viana Lake, Maranhão state, Brazil

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Nivaldo Magalhães Piorski

2005-01-01

Full Text Available Serrasalmus aff. brandtii e Pygocentrus nattereri são duas espécies de piranhas comuns no Lago de Viana, um lago formado a partir das inundações do Rio Pindaré, tributário da margem esquerda do Rio Mearim. Uma amostra composta por 249 exemplares destas espécies foi estudada a fim de identificar a composição da dieta e as estratégias alimentares empregadas pelas duas. Os peixes foram coletados trimestralmente durante um ano, entre março de 1998 e março de 1999, usando redes de emalhar e tarrafas. A composição qualitativa da dieta foi analisada com uso do método de freqüência de ocorrência. As estratégias alimentares empregadas pelas espécies foram inferidas através do método gráfico de Costello (1990, modificado por Amundsen et al. (1996. Os resultados indicaram que peixes foi o item encontrado com maior freqüência nos estômagos de ambas as espécies, seguido de matéria vegetal, com maior participação na dieta de P. nattereri. Os recursos peixes e vegetais tenderam a apresentar relações inversas quando comparados com as diferentes classes de comprimento. A análise gráfica da dieta de P. nattereri e S. aff. brandtii sugere que a maioria dos indivíduos utiliza vários recursos simultaneamente. Uma análise multivariada de índices ecomorfológicos indicou que as espécies são segregadas com relação à habilidade natatória, posição ocupada na coluna d'água e tamanho relativo das presas.Serrasalmus aff. brandtii and Pygocentrus nattereri are two species of piranhas, both common in the Viana Lake, which is formed by the flooding waters of the Pindaré River, a tributary of the left bank of the Mearim River. A sample composed of 249 specimens of these species was studied in order to identify diet composition and feeding strategies employed by the two species. The piranhas were captured thrimonthly, during one year from March 1998 to March 1999 using gill and fishing nets of different mesh sizes. The qualitative

Cytogenetic and morphological diversity in populations of Astyanax fasciatus (Teleostei, Characidae from Brazilian northeastern river basins

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Aline Souza Medrado

2008-01-01

Full Text Available In the present work, morphometric and cytogenetic analyses were carried out in populations of the fish Astyanax fasciatus (Characidae from Contas and Recôncavo Sul River basins (State of Bahia, Brazil, providing new data on the genetic structure of this species along the region. Based on morphologic measurements, we observed that populations from the same hydrographic basin were more similar to each other (Contas and Preto do Costa Rivers, and remarkably divergent from Recôncavo Sul (Mineiro Stream, as indicated by clustering analysis. Cytogenetic data revealed a same diploid number for all populations (2n = 48, but distinct karyotype formulae (8M+24SM+12ST+4A, FN = 92 in Contas River, 8M+24SM+10ST+6A, FN = 90 in Preto do Costa River, and 8M+18SM+16ST+6A, FN = 90 in Mineiro Stream. Ag-NORs were identified at telomeres on a subtelocentric chromosome pair, although multiple ribosomal sites have been detected in some specimens from Contas River. These results show that A. fasciatus populations from northeastern river basins are well differentiated and present peculiar cytogenetic features when compared to populations from other regions. Therefore, the apparent chromosomal plasticity of this species, likely to represent a complex of cryptic forms, is corroborated. Finally, we demonstrated that morphological features can be successfully used to support other sources of genetic information.

Distinct classical and molecular cytogenetics of Astyanax marionae ...

Indian Academy of Sciences (India)

DIOVANI PISCOR

2017-08-24

Aug 24, 2017 ... and A. fasciatus (Characiformes: Characidae): a comparative study of the organization of heterochromatin and repetitive genes. DIOVANI PISCOR1 ..... 7, 363–367. Mirande J. M. 2010 Phylogeny of the family Characidae.

Neotropical Monogenoidea. 24. Rhinoxenus bulbovaginatus n. sp. (Dactylogyridae, Ancyrocephalinae from the nasal cavity of Salminus maxillosus (Osteichthyes, Characidae from the Rio Paraná, Paraná, Brazil

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Walter A. Boeger

1995-12-01

Full Text Available Rhinoxenus bulbovaginatus n. sp. is described from the nose of Salminus maxillosus (Characidae collected in the basin of the rio Paraná, near the city of Porto Rico, state of Paraná, Brazil. The new species can be differentiated from the other three species in the genus by the morphology of the copulatory complex, vagina, and ventral anchor. The sister group relationship of the known species of Rhinoxenus was determined using techniques of Phylogenetic Systematics (Cladism. The resulting cladogram (C.I.=100% indicates that the new species is most closely related to R. piranhus Kritsky, Boeger and Thatcher, 1988. The other two species of the genus, R. arietinus Kritsky, Boeger and Thatcher, 1988 and R. nyttus Kritsky, Boeger and Thatcher, 1988, both parasites of Anostomidae fishes, have a paraphyletic position in the cladogram, suggesting that the origin of at least one of them can not be associated to cospeciation.

Trophic ecology of two piranha species, Pygocentrus nattereri and Serrasalmus marginatus (Characiformes, Characidae, in the floodplain of the Negro River, Pantanal

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Fabiane Silva Ferreira

2014-12-01

Full Text Available AIM: This study aimed to evaluate influence of hydrological variation, ontogeny and interspecific variation in the feeding activity and diet composition for P. nattereri and S. marginatus in floodplain of Negro River, South Pantanal. METHODS: The samples were taken with the use of gillnets and cast nets of different sizes, from October/2005 to August/2008. RESULTS: We sampled 748 specimens, 442 of P. nattereri and 306 of S. marginatus. We identified 31 items in the dry and 14 in the flood season for P. nattereri, and 29 items in the dry and eight in the flood season for S. marginatus. For both species, fish was the predominant food item in both seasons. The PERMANOVA results showed that the diet varied significantly between the two species (p<0.001, during ontogenetic development (p<0.001 and seasonally (p=0.024. The ancova results suggests that the intensity of food intake was higher in the dry season (p<0.001 for both species. The niche breadth varied only between studied species with S. marginatus presenting higher niche breadth than P. nattereri. CONCLUSION: Piranhas feed more during dry season, probably because in this period food is more varied and abundant, due to the concentration of fish in the main river channel. There were ontogenetic changes in the diet, with no feeding overlap between the two species, probably because of differences in preference for some items and differences in feeding behavior displayed during hunting attacks.

Nucleotide diversity of Hemigrammus cf. marginatus (Characiformes, Characidae in the upper Paraná river floodplain - doi: 10.4025/actascibiolsci.v34i3.6669

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Carla Simone Pavanelli

2012-06-01

Full Text Available Characidae is the largest and more diversified family from Characiformes and presents several classification problems, with several genera currently allocated as incertae sedis, such as the genus Hemigrammus. The upper Paraná river floodplain is an environment with high fish diversity. There is at least one species of Hemigrammus, however there are divergences among some authors about the number and the identification of the species from this genus. Therefore the goal of this study was to characterize, using a molecular approach, individuals of Hemigrammus from the upper Paraná river floodplain and to compare them with individuals from the type locality of Hemigrammus marginatus, since this is the only species distributed in this floodplain. For this, the DNA was extracted and a partial region from the mitochondrial genes ATPase 6 and ATPase 8 were amplified and sequenced. The results evidenced the existence of two species of Hemigrammus in the floodplain, although impossible to be distinguished only through morphological traits. High nucleotide diversity among individuals from the upper Paraná river in relation to those from the type locality was also observed, indicating that both species of Hemigrammus present in the upper Paraná river floodplain are not Hemigrammus marginatus. 

Abundance, feeding and reproduction of Salminus sp. (Pisces: Characidae from mountain streams of the Andean piedmont in Venezuela

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Douglas Rodríguez-Olarte

Full Text Available To obtain basic information for management, aspects of the ecology of Salminus sp. (Pisces: Characidae, were studied in piedmont rivers of the southwestern flank of the Andes in Venezuela. Collections were made with seines of various lengths and mesh sizes, and both underwater and terrestrial observations were recorded to estimate abundance and feeding events. Interviews with local fishermen and inhabitants were made to obtain data on use. The species is present along the entire length of the Andean piedmont in Venezuela, although in some rivers it is now scarce. Small individuals form mixed schools with Brycon whitei, but larger Salminus sp. usually only school with others of the same species. Average abundance was greater in larger rivers, and didn't vary appreciably with season for any of the rivers studied. Size and weight ranged from 15.1 to 40.5 cm SL and 47.7 to 1,210 g, respectively. Females had maximum ovary maturity at the beginning of the rainy season, with an average fecundity of 35,834 eggs, and spawning occurred during spates of high water. Feeding was crepuscular, with most events recorded during the first and last hours of sunlight. In smaller fish up to 20 cm SL, the diet was varied, but above that size fish were the principal food item. Salminus sp. has little commercial importance in this region but forms an important part of the local subsistence fishery, and occasionally it is targeted for sport fishing. The minimum legal size of capture for the species should be raised, since the current limit permits the capture of many sexually immature individuals.

HEMOPARASITOS DE PIRANHAS VERMELHAS PYGOCENTRUS NATTERERI (KNER, 1858 (CHARACIFORMES: CHARACIDAE CAPTURADAS NA REGIÃO DO MÉDIO RIO ARAGUAIA, ESTADO DE GOIÁS, GO

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Isabela Vieira Carneiro

2016-07-01

Full Text Available This work aimed to evaluate blood smears of 128 red piranha specimens Pygocentrus nattereri (Kner, 1858 (Characiformes: Characidae as for the presence of hemoparasites and blood cells that were visualized. Samples were collected in Rio Vermelho (Red River (15°10'44.73''S and 51°09'55.83W'', in the Brazilian state of Goiás, between April 2012 and August 2013, including ebb, full and dry phases. After identificating and numbering the piranhas, we collected approximately 0.5 mL of blood from each animal, from the caudal vein or through intracardiac puncture, and two blood smears were done and stained with May GrünwaldGiemsa and Fast Panoptic stains. After euthanasia, the body mass and biometrics of every fish were measured. Abiotic factors of the river water were also analyzed, such as temperature and transparency. In general, the biometric parameters were higher in the full phase of the river, and the values obtained on water quality were similar in relation to the average temperature of the water, which was around 82,4°F. The average transparency of the water varied, being greater at low tide. Erythrocytes, thrombocytes, neutrophils, eosinophils, monocytes, heterophile and lymphocytes were identified as blood cells of red piranhas and hemogregarines have been found in about 25% (32/128 of the blood smears.

Distinct classical and molecular cytogenetics of Astyanax marionae and A. fasciatus (Characiformes: Characidae): a comparative study of the organization of heterochromatin and repetitive genes.

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Piscor, Diovani; Centofante, Liano; Parise-Maltempi, Patricia Pasquali

2017-09-01

Genus Astyanax is well distributed in Neotropical freshwater environments and its taxonomic position is uncertain, as is the case with other Characidae genera allocated in the group incertae sedis. This study aimed to analyse the karyotype of different populations of Astyanax fasciatus (Corumbataí River basin) using Giemsa staining, C-band technique, and fluorescence in situ hybridization for the H3 histone and 5S rRNA genes, in addition we describe for the first time the chromosomal organization of H3 histone and 5S rRNAgenes in A. marionae (ParaguayRiver basin). Chromosomes of three A. fasciatus populations were analysed (two with 2n = 50 and one with 2n = 48) and the heterochromatin was organized in two forms (blocks with blurred boundaries and distinct blocks). H3 histone and 5S rRNA genes were observed in all the three populations of A. fasciatus on two chromosome pairs (one metacentric chromosome showing H3 histone and 5S rRNA gene clusters). In A. marionae (2n = 48), H3 histone and 5S rRNA genes were observed in one acrocentric chromosome pair (different pairs). Further, differences between karyotypes and heterochromatin, as well as the chromosomal organization of H3 histone and 5S rRNA genes in Astyanax species, focussing on chromosome evolution in the group are discussed.

Differential expression of myogenic regulatory factor MyoD in pacu skeletal muscle (Piaractus mesopotamicus Holmberg 1887: Serrasalminae, Characidae, Teleostei) during juvenile and adult growth phases.

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de Almeida, Fernanda Losi Alves; Carvalho, Robson Francisco; Pinhal, Danillo; Padovani, Carlos Roberto; Martins, Cesar; Dal Pai-Silva, Maeli

2008-12-01

Skeletal muscle is the edible part of the fish. It grows by hypertrophy and hyperplasia, events regulated by differential expression of myogenic regulatory factors (MRFs). The study of muscle growth mechanisms in fish is very important in fish farming development. Pacu (Piaractus mesopotamicus) is one of the most important food species farmed in Brazil and has been extensively used in Brazilian aquaculture programs. The aim of this study was to analyze hyperplasia and hypertrophy and the MRF MyoD expression pattern in skeletal muscle of pacu (P. mesopotamicus) during juvenile and adult growth stages. Juvenile (n=5) and adult (n=5) fish were anaesthetized, sacrificed, and weight (g) and total length (cm) determined. White dorsal region muscle samples were collected and immersed in liquid nitrogen. Transverse sections (10 microm thick) were stained with Haematoxilin-Eosin (HE) for morphological and morphometric analysis. Smallest fiber diameter from 100 muscle fibers per animal was calculated in each growth phase. These fibers were grouped into three classes (50 microm) to evaluate hypertrophy and hyperplasia in white skeletal muscle. MyoD gene expression was determined by semi-quantitative RT-PCR. PCR products were cloned and sequenced. Juvenile and adult pacu skeletal muscle had similar morphology. The large number of fish confirms active hyperplasia. In adult fish, most fibers were over 50 microm diameter and denote more intense muscle fiber hypertrophy. The MyoD mRNA level in juveniles was higher than in adults. A consensus partial sequence for MyoD gene (338 base pairs) was obtained. The Pacu MyoD nucleotide sequence displayed high similarity among several vertebrates, including teleosts. The differential MyoD gene expression observed in pacu white muscle is possibly related to differences in growth patterns during the phases analyzed, with hyperplasia predominant in juveniles and hypertrophy in adult fish. These results should provide a foundation for understanding the molecular control of skeletal muscle growth in economically important Brazilian species, with a view to improving production quality.

Caracterización citogenética del pez neotropical Brycon henni (Pisces: Characidae

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Diana David López

2008-12-01

Full Text Available La sabaleta Brycon henni, es un pez nativo del occidente colombiano importante para la seguridad alimentaria de las poblaciones ribereñas y para la pesca deportiva por sus característica combativas. El desarrollarse entre los 18 y 28ºC la convierte en una especie de cultivo promisoria. Un estudio citogenético a partir de células branquiales indicó diferentes complementos cromosómicos. Este trabajo aplicó la técnica de cultivo de linfocitos a muestras de sangre de adultos. Las muestras de sangre total fueron sembradas en 4 ml de medio de cultivo Ham-F12, suplementado con 0.5 ml de Suero Fetal Bovino y 0.7 ml del mitógeno Fitohemaglutinina M (Gibco® durante 96 hr a 28ºC; 1.5 hr antes de la cosecha agregamos 100µl de Colcemid al 10% como factor antimitótico. Cada cultivo se incubó con 10 ml de solución hipotónica KCl 0.56% por 24 min a 37ºC, para continuar con tres fijaciones sucesivas, centrifugaciones y tinción Giemsa al 5%. Las mejores metafases fueron fotografiadas en microscopio, correspondientes a 6 machos y 8 hembras, indicando un número diploide de 50 cromosomas, clasificados en Metacéntricos (26M, Submetacéntricos (16SM y Subtelocéntricos (8ST, para un número fundamental (NF de 100 brazos. La tendencia evolutiva hallada fue de tipo B; no se encontraron cromosomas supernumerarios pero sí un primer par de cromosomas metacéntricos grandes, considerado marcador para el género Brycon, no determinante de heteromorfismo sexual. Estos resultados coinciden con los demás bricónidos investigados, en donde se podría considerar un ancestro común con un número cromosómico básico y cariotipos simétricos.Cytogenetic characterization of the neotropical fish Brycon henni (Pisces: Characidae. Brycon henni, is a native fish from Western Colombia is important as food and in sport fishing, and could be cultured in waters between 18 and 28ºC. A previous cytogenetic study in branchial cells indicated different chromosomal

Copépodes parasitos de fossas nasais de cinco espécies de peixes (Characiformes da planície de inundação do alto rio Paraná, Paraná, Brasil - DOI: 10.4025/actascibiolsci.v29i4.887 Parasitic copepods in the nasal fossae of five fish species (Characiformes from the upper Paraná river floodplain, Paraná, Brazil - DOI: 10.4025/actascibiolsci.v29i4.887

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Maria de los Angeles Perez Lizama

2008-02-01

Full Text Available O presente trabalho teve como objetivo o estudo de copépodes parasitos de fossas nasais de peixes da planície de inundação do alto Rio Paraná. As coletas foram realizadas em diversos pontos da planície nos meses de março, junho e setembro de 2004. Foram coletados 73 exemplares de peixes da ordem Characiformes, de quatro famílias distintas, pertencentes a cinco espécies: Acestrorhynchus lacustris, Prochilodus lineatus, Schizodon borellii, Serrasalmus maculatus e Serrasalmus marginatus. Dentre os 73 peixes examinados, 53 encontravam-se parasitados por copépodes de fossas nasais, variando de 1 a 146 parasitos por peixe. Os parasitos encontrados pertenciam a três espécies conhecidas: Gamidactylus jaraquensis Thatcher & Boeger, 1984; Gamispatulus schizodontis Thatcher & Boeger, 1984 e Rhinergasilus piranhus Boeger & Thatcher, 1988. Diferenças foram observadas nas medidas corporais dos parasitos e na quantidade de espécies de parasitos por espécie de peixe em relação aos copépodes encontrados em estudos anteriores na região amazônica. O presente estudo constitui um dos poucos trabalhos de identificação de copépodes parasitos de fossas nasais de peixes da região Sul do Brazil.The present work had the objective to study parasitic copepods in the nasal fossae of fish from the upper Paraná river floodplain. Fish were captured in different locations of the floodplain in March, June and September, 2004. A total of 73 specimens (Characiformes were collected, belonging to 4 distinct families and 5 species: Acestrorhynchus lacustris (Acestrorhynchidae, Schizodon borellii (Anostomidae, Prochilodus lineatus (Prochilodontidae, Serrasalmus marginatus and Serrasalmus maculatus (Serrasalmidae. Among 73 fishes examined, 53 were parasitized by nasal fossae copepods, varying from 1 to 146 parasites per host. Parasites found belonged to 3 known species: Gamidactylus jaraquensis Thatcher & Boeger, 1984; Gamispatulus schizodontis Thatcher & Boeger

Alterações histopatológicas em fígado de dourado Salminus maxillosus Valenciennes, 1840 (Osteichthyes, Characidae causadas por Neocucullanus neocucullanus Travassos, Artigas & Pereira 1828 (Nematoda “Dourado”, Salminus maxillosus Valenciennes, 1840 (Osteichthyes, Characidae liver histopatologic alterations caused by Neocucullanus neocucullanus Travassos, Artigas & Pereira 1828 (Nematoda

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Antenor Aguiar Santos

2002-05-01

Full Text Available Foram capturados 293 exemplares de Salminus maxillosus Valenciennes, 1840, (Osteichthyes, Characidae no rio Mogi-Guaçu, Cachoeira de Emas, de agosto de 1996 a dezembro de 1997. Amostras de fígado de 45 exemplares que apresentaram parasitos, Neocucullanus neocullanus Travassos, Artigas e Pereira, 1928 (prevalência de 15,35%, foram fixadas em Bouin e processadas para inclusão em parafina. Cortes de 5 µm foram corados por HE, Tricrômico de Mallory e submetidos ao PAS contracorados com Hematoxilina. Macroscopicamente nos fígados que se apresentavam parasitados, havia infecção nas regiões centrais e periféricas, algumas vezes com perfuração do estroma do órgão, permitindo visão do cisto externamente. Microscopicamente e circunscrito à região da instalação do parasito, encontrou-se desorganização intensa do tecido, com células típicas de processo inflamatório ativo e de uma discreta deposição de fibrina ao redor do foco inflamatório. Justaposto ao parasito há a cápsula delgada constituída por fibroblastos e fibras colágenas. A presença de leucócitos e o encapsulamento do parasito demonstram um processo inflamatório agudo.From August 1996 to December 1997, 293 specimens of Salminus maxillosus were captured in the Mogi-Guaçu river, at Cachoeira de Emas, municipality of Pirassununga, state of São Paulo, Brazil. The livers of 45 fishes were parasitized by Neocucullanus neocucullanus Travassos, Artigas and Pereira, 1928 (15.35% prevalence. Liver samples were fixed in Bouin and processed for paraffin inclusion. 5µm-sections were stained with ME, Mallory trichromic and submitted to Hematoxilin-contrasted PAS. Macroscopically, the parasitized livers had central and peripheral infection, sometimes perforating the stroma, allowing the cyst to be seen externally. Microscopically, and only surrounding the parasite, intense tissue disorganization, with typical active inflammatory process cells, and discrete fibrin deposition

Carbon sources and trophic position of the main species of fishes of Baía River, Paraná River floodplain, Brazil

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Manetta G. I.

2003-01-01

Full Text Available In order to verify the carbon source and trophic position of the main species of fishes, of the Paraná River floodplain, we analysed the proportion of stable carbon (delta13C and nitrogen (delta15N isotopes in muscle of fishes sampled in the rainy season. We analyzed adult individuals of Loricariichthys platymetopon, Schizodon borellii, Leporinus lacustris, Auchenipterus osteomystax, Iheringichthys labrosus, Leporinus friderici, and Serrasalmus marginatus. These data were compared with the results obtained by the analyzing stomach contents. The primary producers found in the Baía River were the C3 plants (riparian vegetation, macrophytes, periphyton, and phytoplankton and the C4 plants (macrophytes. The results of the contribution analysis revealed that the carbon used by the species was derived from C3 plants. According to the trophic position estimates (diet and delta15N, the species primarily consumed Loricariichthys platymetopon, Schizodon borellii, Leporinus lacustris, and Leporinus friderici and, secondarily Auchenipterus osteomystax, Iheringichthys labrosus, and Serrasalmus marginatus. There was no significant difference between the two methods utilized.

Two new species of Creptotrema (Digenea: Allocreadiidae from South America Dos especies nuevas de Creptotrema (Digenea: Allocreadiidae de América del Sur

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Stephen S. Curran

2008-08-01

Full Text Available Two new digenean species belonging in Creptotrema Travassos, Artigas and Pereira, 1928 are described from specimens stored in the invertebrate collection at the Museum of Natural History, Geneva, Switzerland. Creptotrema lamothei n. sp. is described from Ageneiosus brevifilis Valenciennes in Cuvier and Valenciennes, 1840 (Siluriformes: Ageneiosidae, Auchenipterus nuchalis (Spix and Agassiz, 1829 (Siluriformes: Auchenipteridae, and Bryconops melanurus (Bloch, 1794 (Characiformes: Characidae in the Paraguay River, Paraguay. Creptotrema sucumbiosa n. sp. is described from Tetragonopterus argenteus Cuvier, 1816 (Characiformes: Characidae in Río Aquarico, Ecuador. Creptotrema lamothei differs from its congeners by having testes with irregular rather than entire outlines. Creptotrema sucumbiosa differs from its congeners by having a bilobed rather than entire ovary. Both C. lamothei and C. sucumbiosa differ from their other congeners by having relatively longer posttesticular spaces in their bodies, representing 25-30% and 24-28% of body length respectively, compared with approximately 6-19% in other species.Dos especies nuevas de digéneos pertenecientes a Creptotrema Travassos, Artigas y Pereira, 1928 fueron descritas de ejemplares depositados en la colección de invertebrados del Museo de Historia Natural de Ginebra, Suiza. Creptotrema lamothei n. sp. fue descrita en Ageneiosus brevifilis Valenciennes in Cuvier y Valenciennes, 1840 (Siluriformes: Ageneiosidae, Auchenipterus nuchalis (Spix y Agassiz, 1829 (Siluriformes: Auchenipteridae, y Bryconops melanurus (Bloch, 1794 (Characiformes: Characidae en el río Paraguay, Paraguay. Creptotrema sucumbiosa n. sp. fue descrita de Tetragonopterus argenteus, Cuvier 1816 (Characiformes: Characidae en el río Aquarico, Ecuador. Creptotrema lamothei difiere de sus congéneres por tener testículos con contornos irregulares en contraste con los que presentan contornos enteros. Creptotrema sucumbiosa difiere de

Genetic diversity and population structure in Meconopsis ...

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STORAGESEVER

2010-05-24

May 24, 2010 ... The location and main ecological characteristics of sample sites are shown in ..... suggest that this is wind-pollinated and allogamous plant species ... (Teleostei, Characidae) from an urban stream, Hydrobiology, 553: 245-254 ...

Fauna parasitária de peixes oriundos de “pesque-pague” do município de Guariba, São Paulo, Brasil - DOI: 10.4025/actascibiolsci.v28i3.253 Parasitic fauna of cultivated fishes in fee fishing farm of Guariba, São Paulo State, Brazil - DOI: 10.4025/actascibiolsci.v28i3.253

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Julieta Rodini Engracia de Moraes

2007-11-01

Full Text Available Este trabalho descreve a ocorrência e a sazonalidade de parasitos em peixes de “pesque-pague” do município de Guariba, Estado de São Paulo, Brasil (21º15`22``S, 48º18`58``W e 595 m de altitude, durante o período de agosto de 2001 a julho de 2002. A presença de parasitos foi pesquisada em pacu Piaractus mesopotamicus (Characidae, carpa comum Cyprinus carpio (Cyprinidae, tilápia-do-Nilo Oreochromis niloticus (Cichlidae, híbrido tambacu (macho de P. mesopotamicus x fêmea de tambaqui-Colossoma macropomum e piraputanga Brycon hillari (Characidae. Os resultados demonstram que dos 100 peixes examinados, 15% estavam parasitados por pelo menos um dos seguintes parasitos: Trichodina sp.; helmintos monogenóides; copepoditos de Lernaea cyprinacea; L. cyprinacea adulta ou Dolops carvalhoi. Por ordem decrescente, o grau de suscetibilidade dos hospedeiros foi C. carpio, P. mesopotamicus, B. hillari, híbrido tambacu e O. niloticus. Por ordem decrescente, os parasitos encontrados foram helmintos monogenóides, Dolops carvalhoi, Trichodina sp., Lernaea cyprinacea adultas e suas formas jovens.This study describes the occurrence and the seasonality of parasites of cultivated fish from a fee fishing farm located in Guariba, São Paulo State, Brazil (21º15`22`` S, 48º18`58`` W and 595 m of altitude, from August, 2001 to July, 2002. The presence of parasites was researched in pacu Piaractus mesopotamicus (Characidae, common carp Cyprinus carpio (Cyprinidae, nile-tilapia Oreochromis niloticus (Cichlidae, tambacu hybrid (male of P. mesopotamicus x female of tambaqui-Colossoma macropomum and piraputanga Brycon hillari (Characidae. Results demonstrate that out of 100 fish examined, 15% were sponged for at least one of the following parasites: Trichodina sp.; monogenean helminths; copepodits of Lernaea cyprinacea; adults of L. cyprinacea; or Dolops carvalhoi. In decreasing order, the susceptibility degree of the hosts was C. carpio, P. mesopotamicus, B

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The sex-ratio of most fish in the lake tends to unity (1:1), suggesting reproductive stability. Condition factors are high for the fish species ... Parachanna obscuraGunther. Snake head. Characidae. Chrysichthys auratusPfaff. Characines. Cichlidae. Hemichromis faciatusPeter. Banded jewel fish. Oreochromis niloticusLinnaeus.

Journal of Genetics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Genus Astyanax is well distributed in Neotropical freshwater environments and its taxonomic position is uncertain, as is the case with other Characidae genera allocated in the group incertae sedis. This study aimed to analyse the karyotype of different populations of Astyanax fasciatus (Corumbataí River basin) using ...

New host records and description of the egg of Anacanthorus penilabiatus (Monogenea, Dactylogyridae

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MC Pamplona-Basilio

2001-07-01

Full Text Available Anacanthorus penilabiatus is referred parasitizing the type-host Piaractus mesopotamicus (Serrasalmidae and two new hosts, Colossoma macropomum and C. brachypomum (Characidae from fish ponds of "Departamento Nacional de Obras Contra as Secas", Pentecoste, State of Ceará, Brazil. Table of measurements and the first description of the egg are presented.

Is 30 years enough time to niche segregation between a non-native and a native congeneric fish species? Evidences from stable isotopes

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Gustavo Henrique Zaia Alves

2015-12-01

Full Text Available The invasion of non-native species that are phylogenetically similar to native species was observed in the Upper Paraná River following the construction of the Itaipu hydroelectric plant and subsequent removal of a natural geographic barrier (Sete Quedas Falls. Endemic fish species from the Lower Paraná River, such as the piranha Serrasalmus marginatus, successfully colonized the new environment. A few years later, S. marginatus had become the dominant species, while the prevalence of the congeneric species, Serrasalmus maculatus, had declined. Considering that the two piranha species naturally coexist in the Pantanal and that S. marginatus is a non-native species in the Upper Paraná River floodplain, we hypothesized that trophic niche overlap between Serrasalmus species only occurred in the Upper Paraná River floodplain due to short-term co-existence. The study area in which the isotopic niche overlap between S. maculatus and S. marginatus was evaluated consisted of two ponds located in different floodplains, the Pantanal and the Upper Paraná River. We used carbon and nitrogen stable isotope analysis to elucidate the differences in the energy intake by the native and non-native species. We used mixing models and calculated the isotopic niche area and niche overlap to infer the nature of the trophic interactions between the species in both habitats. According to the mixing model, the predominant source of carbon for both species was terrestrial. Nevertheless, in Upper Paraná River, the δ13C signature of the two species differed significantly and the non-native species had a greater niche width than the native species. In the Pantanal, there were no differences in δ13C, but the species differed with respect to δ 15N, and the niche widths were narrow for both species.Based on these results, it can be inferred that the species depend on different food sources. Piranhas obtain energy from distinct prey species, which probably consume

Histología y morfometría del ojo del pez dulceacuícola Paracheirodon axelrodi (Characiformes: Characidae

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Mario O Tovar

2009-12-01

Full Text Available El pez dulceacuícola P. axelrodi es de gran importancia comercial en la Orinoquía Colombiana y a nivel mundial, pero carece de estudios acerca de su visión. Se utilizaron diez individuos, con longitud total promedio de 2.7 cm (SD= 0.2, n= 20. Se realizaron cortes a 8 μm y se tiρeron con H-E. El tamaρo relativo del ojo es 9.8% (SD= 1.1, n= 20; el cristalino tiene un tamaρo relativo de 64.3% (SD= 4.9, n=20. Una esclerótica con tejido cartilaginoso. La retina está constituida por ocho capas y dos membranas, hay areae centrales en la zona posterior, por lo tanto tiene mayor espesor que la zona lateral. El espesor promedio de las estructuras es: retina lateral: 144.5 μm (SD= 5.4, n= 20, retina temporal: 210.4 μm (SD= 14.8, n= 20; cristalino (esfιrico: dorso-ventral 759.6 μm (SD= 31.7, n= 20 y antero- posterior 763.4 μm (SD= 30.7, n= 20 y cσrnea: 27.6 μm (SD= 4.3, n= 20. El tamaρo relativo del ojo, relacionado con la presencia de areae centrales y una córnea delgada, muestra las necesidades visuales del neón cardenal (cazador para adaptarse al hábitat, lo que hace necesario tener un sistema visual desarrollado que le permita tener mejor sensibilidad y resolución visual.Histology and morphometry of the eye in the freshwater Paracheirodon axelrodi (Characiformes: Characidae. The visual system of Teleost fishes has a wide range of adaptations. The eye has suffered modifications, mainly towards better sensitivity and visual resolution according to specific environmental conditions. In that way, this organ is so important for survival. In spite of being the most commercialized Orinoquía species, and one of the most important ornamental fish worldwide, there are almost no studies on the communication systems of P. axelrodi (including vision. We studied the eye in ten individuals of P. axelrodi, with a mean total length of 2.7 cm (SD= 0.2, n= 20. We measured eye relative size (TRO after sacrifice. Heads were processed for hematoxylin

Spatial and temporal distribution of fish larvae in marginal lagoons of Pantanal, Mato Grosso State, Brazil

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Karina Keyla Tondato

Full Text Available An analysis was made of the spatial and temporal distribution of the abundance and composition of fish larvae assemblies, aiming to ascertain correlations with biotic and abiotic factors in marginal lagoons of the Cuiabá River floodplain in Brazil's Pantanal wetlands. Samples were collected bimonthly in the pelagic region of the marginal lagoons (fourteen lagoons close to the littoral zone covered by aquatic macrophytes from December 2006 to April 2007. The captured individuals consisted of 2,739 larvae, represented predominantly by Triportheus spp. (Characidae, Parodontidae, Anostomidae, Characidae and Serrasalmidae. Larval density varied among the sample lagoons in December, but the biotic (zooplankton density and abiotic (water temperature, electrical conductivity, dissolved oxygen, pH, water transparency and lagoon depth factors did not significantly affect larval composition and abundance. Larvae were captured throughout the sample period, with the highest densities occurring in December and early January. Temporally, lagoon depth, water transparency and fluviometric level showed a negative correlation with larval density. Both the zooplankton and the larval density vary positively, responding likewise to the environmental conditions imposed by flooding. The highest larval density was also found to coincide with the first rains (early December, when the rainfall has not yet reached its peak.

Efecto de la pluviosidad y el brillo solar sobre la producción y características del semen en el pez Brycon henni (Pisces:Characidae

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C.J Tabares

2006-03-01

Full Text Available El pez Brycon henni es una especie endémica protegida por la legislación colombiana, que habita cuerpos de agua de zonas cafeteras (700-1900 m. s. n. m,comprendidas entre los 4º35’56’’ N y 74º04’51’’ W, con temperaturas que oscilan entre los 18 y los 28ºC. A pesar de las características promisorias de esta especie, su reproducción en cautiverio a nivel comercial no ha sido posible por falta de conocimientos básicos de su biología y comportamiento. El objetivo del presente trabajo fue caracterizar la producción y la fisiología espermática de machos en cautiverio. A lo largo de un año se tomaron 20 muestras de cada uno de 10 ejemplares. El semen se obtuvo mediante masaje abdominal cráneo-caudal y se transportó a 4ºC para su análisis en el laboratorio. Con excepción de septiembre y octubre que fueron los meses más lluviosos, siempre se obtuvo semen de al menos el 50% de los animales. El color, la osmolalidad y el pH fueron similares en todas las muestras a lo largo del año. El volumen, la concentración, la viabilidad, la movilidad y el tiempo de activación fueron variables: El efecto del brillo solar fue positivo sobre el volumen (Spearman pEffect of pluviosity and sun shine on sperm production and seminal characteristics of the fish Brycon henni (Pisces:Characidae. In Colombia the fish Brycon henni is a protected endemic species. It inhabits water bodies in coffee producing areas (700-1900 ma.s.l.; 4º35’56’’ N -74º04’51’’ W; 18-28°C. Insufficient knowledge of its basic biology and behavior prevent the commercial culture of this promising fish. We studied the production and sperm physiology of captive males. Along a year 20 samples were taken from each of 10 males. The sample was obtained by abdominal cefalo-caudal massage and transported to the laboratory at 4°C. Except for September and October (maximum rainfall,sperm was always obtained in at least 50% of the males. Color, osmolality and pH were

BIOMETRY AND COMPOSITION OF FISH SPECIES IN OWENA RESERVOIR, ONDO STATE, NIGERIA

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FAPOHUNDA Olawumi Oluwafunmilola

2007-11-01

Full Text Available A survey of fish species present in Owena reservoir was conducted between October 2004 and March 2005. Fish samples were taken from the catch of the fishermen operating in the reservoir. The results of the survey showed that 14 fish species belonging to seven families were recorded. Two families namely Characidae and Clariidae constituted the dominant fish families in the reservoir. Among the Characidae, Brycinus nurse (23.1% and among the Clariidae family, Clarias gariepinus (22.8% were dominant. Other fish species with significant abundance were Sarotherodon galilaeus (9.3%, Parachanna obscura (8.0%, Clarias anguillaris (7.7% and Oreochromis niloticus (6.4%. The meristic features of the two most abundant fish species caught are as follows: Brycinus nurse had two dorsal spines with eight dorsal fins, two anal spines with eleven anal fins, 25 caudal fins, one pectoral spine and 13 pectoral fins and two ventral spines with seven ventral fins. Clarias gariepinus had 75 dorsal fins, 31 anal fins, 10 caudal fins, six pectoral fins and five ventral fins. The morphometric features of the two most abundant fish species are: Brycinus nurse: total length: 312mm, standard length: 255mm, head length: 60mm, body length: 90mm and body girth: 190mm. Clarias gariepinus: total length: 265mm, standard length: 240mm, head length: 62mm, body length: 62mm and body girth: 130mm.

Fish mercury concentration in the Alto Pantanal, Brazil: influence of season and water parameters.

Science.gov (United States)

Hylander, L D; Pinto, F N; Guimarães, J R; Meili, M; Oliveira, L J; de Castro e Silva, E

2000-10-16

The tropical flood plain Pantanal is one of the world's largest wetlands and a wildlife sanctuary. Mercury (Hg) emissions from some upstream gold mining areas and recent findings of high natural Hg levels in tropical oxisols motivated studies on the Hg cycle in the Pantanal. A survey was made on total Hg in the most consumed piscivorous fish species from rivers and floodplain lakes in the north (Cáceres and Barão de Melgaço) and in the south part of Alto Pantanal (around the confluence of the Cuiabá and Paraguai rivers). Samples were collected in both the rainy and dry seasons (March and August 1998) and included piranha (Serrasalmus spp.), and catfish (Pseudoplatystoma coruscans, pintado, and Pseudoplatystoma fasciatum, cachara or surubim). There was only a small spatial variation in Hg concentration of the 185 analyzed fish samples from the 200 x 200 km large investigation area, and 90% contained total Hg concentration below the safety limit for regular fish consumption (500 ng g(-1)). Concentration above this limit was found in both Pseudoplatystoma and Serrasalmus samples from the Baia Siá Mariana, the only acid soft-water lake included in this study, during both the rainy and dry seasons. Concentration above this limit was also found in fish outside Baia Siá Mariana during the dry season, especially in Rio Cuiabá in the region of Barão de Melgaço. The seasonal effect may be connected with decreasing water volumes and changing habitat during the dry season. The results indicate that fertile women should restrict their consumption of piscivorous fishes from the Rio Cuiabá basin during the dry season. Measures should be implanted to avoid a further deterioration of fish Hg levels.

Fish ladders: safe fish passage or hotspot for predation?

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Angelo Antonio Agostinho

Full Text Available Fish ladders are a strategy for conserving biodiversity, as they can provide connectivity between fragmented habitats and reduce predation on shoals that accumulate immediately below dams. Although the impact of predation downstream of reservoirs has been investigated, especially in juvenile salmonids during their downstream movements, nothing is known about predation on Neotropical fish in the attraction and containment areas commonly found in translocation facilities. This study analysed predation in a fish passage system at the Lajeado Dam on the Tocantins River in Brazil. The abundance, distribution, and the permanence (time spent of large predatory fish along the ladder, the injuries imposed by piranhas during passage and the presence of other vertebrate predators were investigated. From December 2002 to October 2003, sampling was conducted in four regions (downstream, along the ladder, in the forebay, and upstream of the reservoir using gillnets, cast nets and counts or visual observations. The captured fish were tagged with thread and beads, and any mutilations were registered. Fish, birds and dolphins were the main predator groups observed, with a predominance of the first two groups. The entrance to the ladder, in the downstream region, was the area with the highest number of large predators and was the only region with relevant non-fish vertebrates. The main predatory fish species were Rhaphiodon vulpinus, Hydrolycus armatus, and Serrasalmus rhombeus. Tagged individuals were detected predating along the ladder for up to 90 days. Mutilations caused by Serrasalmus attacks were noted in 36% of species and 4% of individuals at the top of the ladder. Our results suggested that the high density of fish in the restricted ladder environment, which is associated with injuries suffered along the ladder course and the presence of multiple predator groups with different predation strategies, transformed the fish corridor into a hotspot for

Estudo dos vestígios de peixes dos sítios arqueológicos da área de influência da Usina Hidrelétrica Machadinho, Rio Grande do Sul, Brasil A study of fish traces taken from the archaeological sites of the areas surrounding the Machadinho Hydroelectric power station, Rio Grande do Sul, Brazil

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Cláudio Ricken

2009-09-01

Full Text Available The analysis of the material obtained in the rescue of archaeological sites in the area surrounding the Hydroelectric Plant of Machadinho, Rio Grande do Sul, revealed that a considerable amount of bones and fish scales incorporated in the alimentary remains. Using an osteological collection as reference, we identified remains of Salminus brasiliensis (Cuvier, 1816 (Characidae, Brycon orbignyanus (Valenciennes, 1849 (Characidae, Pogonopoma obscurum Quevedo & Reis, 2002 (Loricariidae, Hemiancistrus fuliginosus Cardoso & Malabarba, 1999, Prochilodus lineatus (Valenciennes, 1836 (Prochilodontidae, Schizodon sp. (Anostomidae, Leporinus sp. (Anostomidae, Hoplias sp. (Erythrinidae, Hypostomus sp. (Loricariidae and Crenicichla sp. (Cichlidae. Based on specimens from fish collections, regressions were obtained comparing the size of the pre-maxillary bone in Crenicichla spp. and the length of the pectoral fin spine of Hemiancistrus fuliginosus, Pogonopoma obscurum and Hypostomus spp, with the standard length and weight of corresponding specimens. The estimated size and weight of the specimens obtained from fish remains in the archaeological sites varied between 79.7-153.9 mm and 13.5-33.9 g for Hemiancistrus fuliginosus, 158.2-151.0 mm and 179.5-194.3 g for Pogonopoma obscurum, 117.1-166.2 mm and 86.6-93.1 g for Crenicichla spp., and 62.2-397.2 mm and 34-20.3 g for Hypostomus spp. Therefore using these estimates of standard lengths and weights it was possible to formulate a hypotheses on the fishing technology used by the inhabitants of these sites.

Caracterización de la diversidad genética en el pez Brycon henni (Characiformes: Characidae en Colombia central por medio de marcadores RAPD

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Hermes Pineda Santis

2007-12-01

natural.Characterization of the genetic diversity of the fish Brycon henni (Characiformes: Characidae in central Colombia with RAPD markers. Knowledge on the genetic diversity of wild fish species is essential for conservation and appropriate management of individuals in repopulation programs. In Colombia, Brycon henni has been reported in the Magdalena and Cauca river basins, but the population and range have diminished as a consequence of anthropic activities. In this study, the Random Amplified Polymorphic DNA (RAPD was used to estimate the actual genetic structure in this species. For the purpose, six sample sites located in the department of Antioquia (Central Chain Mountains of Colombia were used. Thirty five primers (87.5 %, out of forty used, yielded 1 466 reliable and consistent fragments; 417 were considered as unique fragments able to discriminate among the Magdalena (Humarada-1 and Humarada-2 and Cauca (Piedras, La Clara y Guaracú river basins samples, suggesting that each is a discrete unit. This diversity suggests that anthropic effects of over fishing, dam building, deforestation and water pollution, have contributed to the isolation of these fish groups on the high mountains. Brycon moorei and Colossoma macropomum, as an interspecific control groups, were placed out of the B. henni general group, confirming their taxonomic classification through morphologic data. The RAPD technique was useful to know the genetic diversity and to discriminate among B. henni populations from different geographic origins, as a basis for an appropriate plan of repopulation, conservation and wildlife management. Rev. Biol. Trop. 55 (3-4: 1025-1035. Epub 2007 December, 28.

Metazoan endoparasites of Pygocentrus nattereri (Characiformes: Serrasalminae in the Negro River, Pantanal, Brazil

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Wagner Vicentin

Full Text Available In the period of October 2007 to August 2008, 152 specimens ofPygocentrus nattereri were caught in the Negro River in the Nhecolândia region, central Pantanal wetland, State of Mato Grosso do Sul, Brazil. The specimens were necropsied and a total of 4,212 metazoan endoparasites were recovered, belonging to 10 taxons:Procamallanus (Spirocamallanusinopinatus, Philometridae gen. sp.,Eustrongylides sp., Brevimulticaecum sp.,Contracaecum sp. (Nematoda, Echinorhynchus paranensis (Acanthocephala, Leiperia gracile,Sebekia oxycephala, Subtriquetra sp. 1 andSubtriquetra sp. 2 (Pentastomida. This is the first record of two parasite species from P. nattereri: E. paranensis and L. gracile.

Biologia do saguirú (Characidae, Curimatinae

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P. de Azevedo

1938-01-01

Full Text Available In Brazil all the fishes belonging to the sub-family Curimatinae are called « saguirú ». The present work gives a biological study of the Curimatus elegans Steind., a small fish without any economical importance, which is to be found along the whole brazilian coast, down till Paraguay. The specimens utilized for the present study come from Fortaleza (Ceará, north-eastern Brazil. The C. elegans is « ilyophagus », that means, it feeds itself exclusively with those organic materials to be found in mud, specially with microscopical algae. The intestines are very extent, some of them measuring about 9 to 11 times body's length. Studies have been made about growth and age of the C. elegans; the biggest sizes found were of 153 mm. for females and 88 mm. for males. The C. elegans shows developed sexual glands during a long period (April to September. The movements of the spermatozoa, in contact with water is of 40 to 50 seconds of intense movements, ceasing after 70 to 100 seconds. In contact with 0.5% NaCl-solution spermatozoa show a big increase in movements-time, that can last till about 25 minutes. The eggs' diameter measures 0.70 to 0.73 mm., mature and hydrated it attains 0.93 to 1,00 mm. There is a certain correlation between the size of the body and the quantity of eggs. Big specimens can produce a total of 200.000 eggs. The average quantity contained in 1 gr. and 1 cc. is 6018 and 6229 eggs, respectively. Maturity and spawning in laboratory has been obtained due to injections of suspension of fish-hypophysis. Three or four hours after the injection, fishes show more movement and evident signs of excitation, proceeding spawning after 5 to 6 hours. Males, persecuting females, describe successive circles (merry-go-round - carroussel, swimming side by side with females up to water's surface, where sexual products are start beating dry, for there is no blood yet. Circulation-scheme is to be found on fig. 4 and 5. The swim-bladder and the stomach are but delineated; the intestine is formed by a cylindric tube, all closed. At the place, where later on there will open the mouth, we find a group of ciliary hairs that produce a liquid current, very evident by the semi-circle formed by attached solid particles. After 36 hours, opening of the mouth and formation of the gill slits begin. At the age of 90 hours (4 mm. the larvas swim well and start to feed themselves; the digestive tube is now all open and the swimbladder works already. During the first days of life, larvas have an adhesive organ situated at their frontal region (fig. 7 in form of a crescent, by means of which they hang to surrounding vegetation (fig. 6. When the larva begins to swim and to feed itself and its yolk are having been absorbed. the adhesive organ retracts and disappears. While larvas and alevins feed themselves with plancton, they have small eye-teeth, which disappear,. when fishes become « ilyophagus ». There exist too, during their life as larvas, pharyngeal-teeth. The lateral line appears in the larva after 16 to 18 days; more or less at the same time all fins are completely developed. Shortly after, first scales appear (20 to 23 days. Evolution of intestines twisting followed (fig. 9. Larvas show at different parts of their bodies small of organs excretory functions, that are constituted by bottons in serial disposition, every one with an excretory canal that opens towards the outside. These formations disappear suddenly when larvas attain their phase of alevin. The existence of a great number of said formations at the caudal fin (fig. 12 is of great interest. In our experiences of breeding we have employed several thousands of C. elegans larvas in different environs and we made conditions of surrounding change (illumination, depth of water, temperature, presence of sand at bottom of aquariums and without sand, food. In this way we could compare the results obtained, estimate the action of each factor for the realisation of a good bring-up of larvas.

Alimentación del pez insectívoro neotropical Creagrutus bolivari (Pisces: Characidae según los métodos gráfico y de importancia relativa

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Mario Ortaz

2006-12-01

Full Text Available Se estudió la alimentación de un pez neotropical (Creagrutus bolivari usando diferentes métodos: el método gráfico de Cortés (1997 y dos índices de importancia relativa (George y Hadley, 1979 (% RIi y Cortés, 1997 (% IRIi. Sólo las presas discretas (invertebrados acuáticos y terrestres se emplearon en el análisis de dieta. Se estimó ara cada ítem, las frecuencias de aparición (% A, numérica (% N y gravimétrica (% G. Se analizó un total de 240 ejemplares (intervalo de talla desde 25.3 hasta 64.7 mm de longitud estándar. Para valores de % A > 50 %, el % IRIi resultó mayor al obtenido para el % RIi, con una tendencia opuesta (hasta 130 veces para valores de % A por debajo del 50 %. El % IRIi sobreestimó la importancia relativa de las presas para valores altos de % A, mientras que subestimó la importancia relativa de las presas para valores bajos de % A y mostró un comportamiento no lineal a medida que varió el % A. Las variables empleadas en el método gráfico de Cortés son insuficientes para evaluar la estrategia alimentaria del depredador (generalismo-especialismo. De este modo, se sugiere incluir otras variables como el ancho de nicho trófico poblacional e individual así como un adecuado registro de campo. Es necesario un amplio registro de campo para clasificar a las presas como escasa o dominante de acuerdo a la clasificación de Cortés. Los índices compuestos que incluyen las variables: masa, número y aparición proporcionan una descripción más precisa de la dieta y permiten realizar estudios comparativos. El análisis gráfico es fácil de interpretar y ayuda a evaluar aspectos como la importancia de la presa y la estrategia alimentaria del depredadorThe diet of the neotropical insectivorous fish Creagrutus bolivari (Pisces: Characidae according to the "graphic" and "relative importance" methods. The diet of a neotropical fish species (Creagrutus bolivari was studied using different methods: the Cortés 1997

Fishes from the Itapecuru River basin, State of Maranhão, northeast Brazil

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MC Barros

Full Text Available The Itapecuru is a relatively large river in the northeastern Brazilian state of Maranhão. During several expeditions to this basin, we collected 69 fish species belonging to 65 genera, 29 families and 10 orders. Characiformes and Siluriformes were the orders with the largest number of species and Characidae, Loricariidae, Cichlidae, Auchenipteridae and Pimelodidae were the richest families. About 30% of the fish fauna of the Itapecuru basin is endemic or restricted to northeastern Brazil. Just over a fifth (22% of the species is also known to occur in the Amazon basin and only a few are more widely distributed in South American.

(PISCES: CHARACIDAE)IN LAKE MclLWAINE, RHODESIA

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, but the species is of little economic importance in the lake. The breeding season is short and coincides with the main river floods. Females are larger than males and fecundity is extremely high. Like other A/este.t species it is a very versatile ...

Comparison of the Condition Factor of Five Fish Species of the Araguaia River Basin, Central Brazil

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Bruno Bastos Gonçalves

2016-06-01

Full Text Available This study aims to assess the condition factor (K of five fish species (Serrasalmus rhombeus, Psectrogaster amazonica, Loricaria cataphracta, Panaque nigrolineatus and Squaliforma emarginata. Samplings were conducted during the low-water period of 2007 and 2008 using gillnets and minnow traps. All equipments were placed along a stretch of 1000 m at 5 pm and retrieved at 7 am. Collected fish were taxonomically identified, weighed (g and measured (standard length; mm. The fish fitness was assessed by the condition factor (K=W/L³ and compared among groups of tributaries by a Kruskal-Wallis test. From the five species considered, two (S. emarginata and P. amazonica displayed significant differences of the condition factor among the groups of tributaries. The highest values of K correspond to fish located in the headwaters, while lowest values are observed in tributaries located in the floodplain.

Perfil Ictiofaunístico de duas Lagoas no Rio Paraná, Região do Parque Nacional de Ilha Grande - PR. = Ictiofaunistic profile of two Rio Paraná lagoons, Region of Ilha Grande National Park - PR.

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Wladimir M. Domingues

2008-07-01

Full Text Available O Rio Paraná é o décimo maior do mundo em descarga e nele se encontra a região do Parque Nacional de Ilha Grande, que é formada por um conjunto de ilhas, lagoas e várzeas periodicamente alagadas, sendo estas de extrema importância para os peixes, servindo de refúgio contra predação, berçário natural e áreas de alimentação para muitas espécies de peixes. Este artigo apresenta um levantamento icitiofaunístico nas lagoas Saraiva e São João, situadas no Parque Nacional de Ilha Grande, com enfoque nas variações espaço-temporais, na composição específica e estrutura etária das assembléias de peixes, sendo que estes foram amostrados em coletas trimestrais, utilizando-se redes de espera de diferentes malhagens. Em termos de número de indivíduos capturados e proporção, tem-se 54% das espécies pertencentes a ordem Characiformes, 42% a Siruliformes, 3% a Perciformes. Rajiformes e Gymnotiformes contribuíram com menos de 1,5% do total das capturas. Na lagoa Saraiva foram capturadas 34 espécies pertencentes a cinco ordens e 17 famílias, destacando-se numericamente Loricariichthys platymetopon, Raphiodon vulpinus, Serrasalmus marginatus e Plagioscion squamosissimus. As maiores contribuições em peso foram proporcionadas por R. vulpinus, Potanotrygon motoro, P. squamosissimus e S. marginatus. Na lagoa São João ocorreram 46 espécies pertencentes a cinco ordens e 17 famílias, destacando-se em número L. platymetopon, Acestrohynchus lacustris, Serrasalmus spilopleura e S. marginatus. Em peso, Prochilodus lineatus, A. lacustris, L. platymetopon e Serrasalmus spilopleura foram as mais representativas. Destaca-se que a maioria das espécies registradas em ambas as lagoas são típicas de ambientes lênticos, utilizando esses locais para seu desenvolvimento e crescimento. = Paraná River is the tenth river in the world concerning to discharge and surrounding it Ilha Grande National Park region is localized, wich is formed by a

Records of new localities and hosts for crustacean parasites in fish from the eastern Amazon in northern Brazil.

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Oliveira, Marcos Sidney Brito; Corrêa, Lincoln Lima; Oliveira Ferreira, Drielly; Neves, Lígia Rigor; Tavares-Dias, Marcos

2017-06-01

The aim of this study was to investigate parasites crustacean fauna in Arapaima gigas , Cichla monoculus , Cichla ocellaris , Cichla jariina , Satanoperca jurupari , Leporinus friderici , Leporinus fasciatus , Hoplias malabaricus , Phractocephalus hemioliopterus , Serrasalmus altispinis , Pseudoplatystoma tigrinum and Potamotrygon motoro of the State Amapá and Pará, in northern Brazil. A total of 242 parasites, including Argulus elongatus , Argulus multicolor, Argulus juparanaensis , Argulus nattereri , Dolops discoidalis , Dolops longicauda , Braga patagonica , Braga fluviatilis , Livoneca guianensis and undetermined Lernaeidae, were collected from these hosts. The Argulus species had the greatest richness among the community of parasitic crustaceans. There was a low abundance of parasites among the hosts, other than D. discoidalis , was most abundant in the integument of A. gigas and P. tigrinum . Finally, the present study reported nine new hosts for the crustacean parasite species and expanded knowledge of the occurrence of some parasite species in the Jari River basin, in eastern Amazon.

Seleção de presas emalhadas em redes de espera por piranhas, Serrasalmus spilopleura e S. marginatus (Pisces, Serrasalmidae Selection of netted prey by piranhas, Serrasalmus spilopleura and S. marginatus (Pisces, Serrasalmidae

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Elineide Eugenio Marques

2001-05-01

Full Text Available A freqüência de ataque de piranhas aos peixes emalhados foi analisada a partir de capturas mensais utilizando redes de espera, expostas durante 24 horas, com despescas a cada 8 horas, no período de junho de 1987 a maio de 1988, em lagoas, canais e rios da planície de inundação do alto Paraná, Brasil. Os peixes capturados foram identificados e as marcas de ataque de piranhas às nadadeiras e ao corpo registradas. A probabilidade de detecção das espécies emalhadas, a estrutura corpórea e aspectos comportamentais foram os fatores determinantes do ataque seletivo das piranhas. A relação da freqüência de ataque com a abundância relativa de presas por predador não foi significativa. A composição da comunidade foi o fator determinante da freqüência de ataque diferenciada entre os ambientesThe frequency of attacks by piranhas on specimens of netted fish was analyzed from monthly catches in gill nets set out for 24 hours and checked every 8 hours, from June 1987 through May 1988, in lakes, channels, and rivers of the upper Paraná river floodplain, Brazil. Captured fish were identified and marks of attack by piranhas on their fins and flesh were recorded. The probability of detection of netted fishes, their body structure, and behavioral aspects were the factors determining the selective piranhas attacks. There was no significant relationship between the frequency of predator attacks and the relative abundance of the prey. Community composition was the main factor determining the attack frequency, which differed according to environment

Determinantes ambientais da ocorrência de espécies de peixes em riachos de cabeceira da bacia do rio Ivinhema, alto rio Paraná - DOI: 10.4025/actascibiolsci.v29i2.520 Environmental determinants of fish species occurrence in headwaters streams of Ivinhema river basin, upper Paraná river - DOI: 10.4025/actascibiolsci.v29i2.520

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Thiago Rota Alves Felipe

2007-12-01

Full Text Available Com o objetivo de quantificar a importância de algumas características fisiográficas dos riachos sobre a ocorrência de quatro espécies de Characidae em riachos de cabeceira na bacia do rio Ivinhema, realizaram-se amostragens bimestrais em dez riachos com uso de telas de isca, com esforço amostral padronizado. A influência das variáveis ambientais sobre a ocorrência das espécies de peixes foi quantificada utilizando-se do modelo da análise de regressão logística. Constatou-se que a velocidade da correnteza foi o principal fator limitante da ocorrência de Serrapinnus notomelas, Hemigrammus marginatus e Moenkhausia sanctaefilomenae, enquanto a profundidade dos riachos foi o principal determinante da ocorrência de Bryconamericus stramineus. Assim, as primeiras espécies ocorrem predominantemente em locais com baixa velocidade da correnteza, enquanto B. stramineus ocorre principalmente em locais com pouca profundidade e com elevada velocidade da correnteza, sugerindo que as características fisiográficas dos habitat sejam importantes determinantes da colonização e persistência das espécies. Palavras-chave: distribuição espacial, peixes de riachos, bacia do rio Ivinhema.In order to quantify the importance of some physiographic characteristics of headwaters streams of Ivinhema basin on occurrence of four Characidae species, bimonthly samples in 10 streams using a rectangular sieve, with standardized sampling effort were collected. The influence of environmental descriptors on species occurrence was quantified using a logistic regression model. It was observed that the water velocity was the main limiting factor to occurrence of Serrapinnus notomelas, Hemigrammus marginatus and Moenkhausia sanctaefilomenae while stream depth was the main determinant of Bryconamericus stramineus occurrence. Thus, the first three species are found mainly in sites with less water velocity, while B. stramineus is found mainly in sites with less depth

Comparison of fish assemblages in two littoral habitats in a Neotropical morichal stream in Venezuela

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Carmen G. Montaña

Full Text Available Morichales are lowland streams in South American savannas with riparian forest dominated by the moriche palm (Mauritia flexuosa. We sampled littoral habitats from ten flooded vegetated patches (dominated by Mauritiella aculeate and six sand banks in two months of the dry season (Feb-Mar 2005 in a stream in the savannas of Apure State, Venezuela. We collected samples that compromised 12,407 individual fishes of 107 species. Small-bodied fishes (< 100 mm, representing diverse trophic and life history strategies, were abundant. The most abundant species were in the families Characidae and Cichlidae. Fish assemblages from flooded vegetated patches differed significantly from those on adjacent sand banks. High structural complexity along vegetated shoreline habitats of morichal streams likely contributes to species richness and affects assemblage composition.

A morphological study on the African genus Micralestes (Characidae

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Pier Giorgio Bianco

2015-12-01

Full Text Available The study is based on the compared morphology of most of Micralestes nominal taxa, described from whole Africa, with particular attention to the dentition, meristics counts and, in several cases, the color pattern. Type materials and more than 1.500 additional specimens were analyzed. The genus is spread in sub-sahariana areas, and the Nile. Is absent in estern Africa and the southernmost area of South Africa. About 11 species were recognized. The most spread species are: M. humilis which is found from western Africa to the head water of River Sobat (White Nile basin, and the Congo basin, and M. elongatus which range from western Africa to the Nile Basin, but absent in central and southern Africa All others species have restricted ranges: M. occidentalis in basins of western Africa; M. woosmani, M. holargyreus, M. congicus, M. neglectus. M.ambiguous and M. schelly, are all endemic of Congo Basin. M. acutidens was found only in rivers of southern Africa and I did not found any specimens in the Congo basin which can be identified as this species. In Lake Rudolf exist a populations previously identified as M. acutidens which cannot be assigned to any known species and it should be considered as a new one.

Plasticity in the diet of Astyanax taeniatus in a coastal stream from south-east Brazil

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LR. Manna

Full Text Available In this work we aimed to characterise the diet of Astyanax taeniatus (Jenyns 1842 (Characiformes, Characidae along the Mato Grosso stream and we hypothesised that the diet of this species would vary according to spatial, seasonal and ontogenetic differences. Specimens were collected every second month at three sites with different physical attributes. The feeding habits of 651 specimens were analysed using the Alimentary Index (IAi. Analysis of the diet showed an effect of spatial, temporal and ontogenetic factors. Vegetal allochthonous items were more important in the diet of Astyanax taeniatus in upstream sites while animal autochthonous items were more important downstream. Ontogenetic differences in the diet were significant only in upstream sites, where adults consumed a greater amount of vegetal matter than juveniles. These results reinforce the idea that Astyanax species are opportunistic and show trophic plasticity.

Gill rakers in six teleost species: influence of feeding habit and body size

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Ana Paula Gottlieb Almeida

2013-12-01

Full Text Available This study analyzed the structure of the gill rakers of Parapimelodus valenciennis and Parapimelodus nigribarbis (planktivorous, Serrasalmus maculatus and Hoplias malabaricus (piscivorous, Iheringichthys labrosus (benthophagous and Hypostomus commersonii (detritivorous and related it with the body size and feeding habits of these species. The species of Parapimelodus and H. commersonii showed long, filiform and closely spaced gill rakers, similar to those of species that use the gill rakers as a filter to assist in the retention of small particles. The widely spaced gill rakers of I. labrosus probably allow the retention of insect larvae, but not particles of inorganic matter. In H. malabaricus and S. maculatus the gill rakers are most likely related to prey capture and swallowing, as observed in other piscivorous species. In general, gill raker length and the distance between gill rakers have a positive relationship with fish length. The gill rakers show adaptations related to the diet of the fish, but morphological variation may occur even between species whose feeding habits are the same.

Putative relationships among inseminating and externally fertilizing characids, with a description of a new genus and species of Brazilian inseminating fish bearing an anal-fin gland in males (Characiformes: Characidae

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Stanley H. Weitzman

Full Text Available A new inseminating fish species of the family Characidae, Bryconadenos tanaothoros, from tributaries of the upper rio Xingu and upper rio Tapajós basins, Mato Grosso, Brazil is described as the type species of a new genus. This new species and the genus are characterized by a glandular organ on the anterior region of the anal fin of sexually mature males, curved lower jaw teeth, and an inseminating reproductive mode. This new genus is hypothesized as most closely related to Attonitus, a genus with three inseminating species from Peru. Bryconadenos and Attonitus are suggested as related to certain inseminating, but undescribed characid species of uncertain relationships that are similar in certain respects to species of the glandulocaudine Planaltina and to the inseminating species of Knodus. These and a few other inseminating characids are included in a previous tentative characid subgroup designated as Clade A. No species among a relatively small sample of the many species of the Clade A genus Bryconamericus were found inseminating, except Bryconamericus pectinatus. However, newly collected specimens of B. pectinatus were found to have caudal-fin squamation like that of the species of Knodus and this species is here tentatively referred to Knodus. Our investigations indicate that at least several species of Knodus, including the type species, Knodus meridae, are not inseminating, but we found two inseminating apparently new characid species that currently would be referred to Knodus. These species lack the derived anal-fin rays present in the males of K. pectinatus. Other Clade A taxa known to be inseminating, such as two species of the large genus Creagrutus, three species of Monotocheirodon (two undescribed, and the species and genera of the characid subfamily Glandulocaudinae are briefly discussed regarding possible relationships to Attonitus and Bryconadenos. The anatomical aspects of the primary and secondary sexual characteristics of

Suplementação de lisina e metionina em dietas com baixo nível protéico para o crescimento inicial do pacu, Piaractus mesopotamicus (Holmberg Lysine and methionine supplementation in diets with low protein level for the initial growth of pacu Piaractus mesopotamicus (Holmberg

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Adriana Patrícia Muñoz-Ramírez

2002-04-01

Full Text Available O objetivo deste trabalho foi estudar os efeitos da suplementação de metionina ou lisina em dietas com baixo teor protéico para o crescimento do pacu Piaractus mesopotamicus (Holmberg (Characiformes, Characidae. Foram formuladas uma dieta basal com 22% de proteína bruta (PB, 4100kcal de energia bruta (EB/kg, 0,42% de metionina e 1,16% de lisina e outras 6 dietas, com a mesma formulação básica, suplementadas com 0,2, 0,4 ou 0,6% de metionina ou lisina. Uma 8ª dieta (controle continha 26% PB, 4100kcal EB/kg, 0,48% metionina e 1,43% de lisina. As dietas foram administradas à vontade a 144 alevinos com 14,98 ± 1,16g de peso médio inicial. As médias de ganho em peso, eficiência de retenção de energia bruta e dos consumos alimentares da dieta controle mostraram-se maiores (P The objective of this research was to study the effects of methionine or lysine supplementation in diets with low protein level for growth of pacu Piaractus mesopotamicus (Holmberg (Characiformes, Characidae. Diets were formulated as a basal diet presenting 22% crude protein (CP, 4100 kcal gross energy (GE/kg, 0.42% of methionine and 1.16% of lysine and other six diets, with the same basic formulation, supplemented with 0.2%, 0.4% or 0.6% methionine or lysine. An eighth diet (control contained 26% CP, 4100 kcal (GE/kg, 0.48% methionine and 1.43% of lysine. The diets were administered ad libitum to 144 fingerlings with initial medium weight of 14.98 ± 1.16 g. Averages weight gain, gross energy efficiency retention and feed intake for the control treatment were significantly higher (P < 0.05 than those of smaller protein level diets. Averages protein retention efficiency were only higher (P < 0.01 in the diets supplemented with lysine, showing the advantages of lysine supplementation in diets with low crude protein level. A higher growth of pacu was confirmed with diets containing 26% of CP.

Hematology, micronuclei and nuclear abnormalities in fishes from São Francisco river, Minas Gerais state, Brazil = Hematologia, micronúcleos e anomalias nucleares em peixes do rio São Francisco, Estado de Minas Gerais, Brasil

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Robson Seriani

2011-01-01

Full Text Available This study aimed to determine the variables leukocytary, erythrocytary, frequency of micronuclei and nuclear abnormalities in peripheral erythrocytes of Prochilodus argenteus, Pimelodus maculatus and Myleus micans from São Francisco river basin, Minas Gerais State, during the summer and winter. Thrombocytes, hematocrit and leukocyte of P.argenteus series, was influenced by climatic conditions. In P. maculatus, not were significant differences for all leukocytes and thrombocytes. In M. micans, values are unprecedented in the literature, with MCV and absolute number of leukocytes found superior to other species of the family Characidae. The frequency of micronuclei and nuclear abnormalities in erythrocytes, the three species not showed seasonal differences between the sites. However, the highest values were found in summer. Furthermore, we observed a positive correlation between the increase in the percentage of micronuclei with nuclear abnormalities.O presente estudo teve como objetivo, determinar as variáveis leucocitárias, eritrocíticas, freqüência de micronúcleos e anomaliasnucleares nos eritrócitos do sangue periférico de Prochilodus argenteus, Pimelodus maculatus e Myleus micans de um trecho da bacia do rio São Francisco, Minas Gerais, no verão e inverno. Trombóctios, hematócrito e a serie leucocítária de P.argenteus, foi influenciado pela sazonalidade. Em P. maculatus, não ocorreram diferenças significativas para todos os leucócitos e trombócitos. Em M. micans, os valores são inéditos na literatura, apresentando VCM e número absoluto de leucócitos superior ao encontrados para outras espécies dafamília Characidae. A freqüência de micronúcleos e de anomalias nucleares nos eritrócitos, nas três espécies não apresentou diferenças sazonais e entre os pontos amostrais. No entanto, os valores mais altos foram encontrados no verão. Além disso, foi possível observar correlação positiva entre o aumento da

Swimming performance of the small characin Bryconamericus stramineus (Characiformes: Characidae

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Miriam A. de Castro

2010-01-01

Full Text Available Very little research has been conducted on the swimming capacity of Neotropical fish. The few studies available have focused on large migratory species. The present study used fixed and increasing velocity tests to determine prolonged and sustained speeds of the "pequira", Bryconamericus stramineus Eigenmann, 1908, a small, abundant species found in fish passages implemented at the Paraná basin, Brazil. The results of increasing velocity tests showed significant relationships between critical speeds, total and standard lengths, and body weight. When compared with other Neotropical fish, the "pequira" is able to swim faster than individuals of other species of similar length. The point of change from sustained to prolonged swimming was found to occur at an approximate speed of 8.7 lengths per second. These data provide guidance and criteria for design and proper maintenance of structures such as fishways, fish screens and other systems that aim to facilitate or avoid upstream passages as part of management strategies.

Paraoxonase activity in liver of Pacu, Piaractus mesopotamicus Holmberg (Characidae

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Vera Lucia F. Cunha Bastos

1998-01-01

Full Text Available Enzymatic production of p-nitrophenol in liver of Piaractus mesopotamicus Holmberg, 1887 was consistently assayed at pH 8.5 using 7.5 mM paraoxon as substrate. This pacu liver paraoxonase activity was activated by NaCl. Apparent values of K M were 2.42 x 10-3 M in the presence of 0.5 M NaCl and 8.99 x 10-3 M without NaCl. Apparent maximum velocity values calculated in the absence and presence of 0.5 M NaCl were 1.09 x 10-3 µmoles/min/mg of proteins and 1.29 x 100-3 µmoles/min/mg of proteins, respectively. These Vmax values are fifty-fold the value described for trout (Salmo trutta Linnaeus, 1758 liver paraoxonase. Paraoxonase activity of pacu liver homogenates was recovered as much in cytosolic as in particulate cellular subtractions, but the particulate subtractions showed higher specific activities. The data presented here indicate that hepatic hydrolysis of organophosphorous pesticides may not be an important detoxification process in pacu.

Spatial pattern of a fish assemblage in a seasonal tropical wetland: effects of habitat, herbaceous plant biomass, water depth, and distance from species sources

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Izaias M Fernandes

Full Text Available The influence of habitat, biomass of herbaceous vegetation, depth and distance from permanent water bodies on the structure of fish assemblages of a seasonal floodplain was evaluated using data collected along 22 transects in an area of 25 km² in the floodplain of Cuiabá River, Pantanal, Brazil. Each transect was sampled for fish using throw traps and gillnets during the flood period of 2006. Multivariate multiple regression analysis and multivariate analysis of covariance indicated that depth was the only variable that affected the structure of the fish assemblage, both for quantitative data (abundance and qualitative data (presence-absence. Species such as Neofundulus parvipinnis and Laetacara dorsigera were more abundant in shallower sites (below 25 cm, while Serrasalmus maculatus and Metynnis mola were found mostly in the deepest areas (over 55 cm. However, species such as Hoplias malabaricus and Hoplerythrinus unitaeniatus occurred at all sampled depths. Although the distribution of most species was restricted to a few sites, there was a positive relationship between species richness and depth of the water body. Surprisingly, the replacement of native vegetation by exotic pasture did not affect the fish assemblage in the area, at the probability level considered.

First study on infestation of Excorallana berbicensis (Isopoda: Corallanidae on six fishes in a reservoir in Brazilian Amazon during dry and rainy seasons

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Huann Carllo Gentil-Vasconcelos

2015-11-01

Full Text Available We analyzed the infestation levels of Excorallana berbicensis on Acestrorhynchus falcirostris, Ageneiosus ucayalensis, Geophagus proximus, Hemiodus unimaculatus, Psectrogasterfalcata and Serrasalmus gibbus in a reservoir in the Araguari River basin, northern Brazil, during the dry and rainy seasons. For P. falcata, the infestation levels due to E. berbicensis were greater during the rainy season. For all the species studied, the peak parasite prevalence was in the month of highest rainfall levels and there were two peaks of parasite abundance: one in the month with highest rainfall level and the other in the month of transition from the rainy season to the dry season. In these hosts, around 70% of the E. berbicensis specimens were collected during the rainy season. The body conditions of the hosts also did not suffer any seasonal influence. Despite the differences in seasonal rainfall levels, there was no fluctuation in transparency, turbidity, pH, electric conductivity, temperature and dissolved oxygen levels in the water, due to the stability of these parameters during the seasonal cycle investigated in this artificial Amazon ecosystem. This was the first report on the seasonality of infestation by E. berbicensis associated with fish.

Dinâmica populacional da matrinxã Brycon amazonicus (Characidae na Amazônia Central Population dynamics of matrinxã Brycon amazonicus (Characidae in Central Amazon

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Leocy C. dos Santos Filho

2009-06-01

Full Text Available The matrinxã, Brycon amazonicus (Spix & Agassiz, 1829 is one of the most important fishery resources of the Amazonas state. Its population dynamics in Central Amazon was analyzed based on total landing and biometry data registered in the main landing port of Manaus, between 1994 and 2002. Growth and mortality rates were estimated separately for the rivers Purus, Madeira and Solimões. Differences in size structure and growth curves suggest that different population units exist among these rivers, requiring individualized evaluation and fisheries management strategies. The analysis of the yield per recruit does not indicate overexploitation. However, the highest relative exploitation rate was observed in the Madeira river. The suggested management strategies are related to restrictions to the fishery in the main fishing grounds during the migratory dispersal period, instead of restrictions during reproductive periods.

Diet of Lontra longicaudis (Carnivora: Mustelidae in a pool system in Atlantic Forest of Minas Gerais State, southeastern Brazil=Dieta de Lontra longicaudis (Carnivora: Mustelidae em um sistema de poções na Floresta Atlântica do Estado de Minas Gerais, sudeste do Brasil

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Fernando Marques Quintela

2012-10-01

Full Text Available The present study aimed to investigate the feeding habits of Lontra longicaudis in a pool system within the Private Reserve of Natural Patrimony (RPPN Usina Maurício, located in Paraíba do Sul river basin, Atlantic Forest of southeastern Minas Gerais State. The diet composition was determined based on the identification of items present in 212 scats sampled between July 2008 and October 2009 in a 4.1 km stretch of the pool system. The found items and its respective percentages of occurrence were: mollusks (0.5%, insects (16.5%, spiders (1.4%, crustaceans (3.3%, fish (96.7%, amphibians (0.9%, snakes (3.8%, birds (2.8%, mammals (8.5% and fruits (0.5%. Among fish, the identified families and respective percentages of occurrence were: Loricariidae (65.4%, Pimelodidae (42.9% Cichlidae (22%, Characidae (7.3%, Erythrinidae (3.9%, Synbranchidae (2.4%, Anostomidae (2%. Therefore fish make up the most consumed item in the study area, with the predominance of benthic siluriformes (families Loricariidae and Pimelodidae. O presente estudo teve como objetivo investigar os hábitos alimentares de Lontra longicaudis em um sistema de poções na Reserva Particular do Patrimônio Natural – RPPN Usina Maurício, localizada na bacia do rio Paraíba do Sul, Mata Atlântica do Sudeste do Estado de Minas Gerais. A composição da dieta foi determinada com base na identificação de itens presentes em 212 amostras de fezes coletadas entre julho de 2008 e outubro de 2009 em um trecho de 4,1 km de um sistema de poções. Os itens alimentares encontrados e suas respectivas porcentagens de ocorrência foram: moluscos (0,5%, insetos (16,5%, aranhas (1,4%, crustáceos (3,3%, peixes (96,7%, anfíbios (0,9%, serpentes (3,8%, aves (2,8%, mamíferos (8,5%, frutos (0,5%. Dentre os peixes, famílias identificadas e suas respectivas porcentagens de ocorrência foram: Loricariidae (65,4%, Pimelodidae (42,9% Cichlidae (22%, Characidae (7,3%, Erythrinidae (3,9%, Synbranchidae (2

Diâmetro do ingrediente e a digestibilidade aparente de rações por duas espécies de peixes tropicais Ingredient diameter and apparent digestibility of diet by two tropical fish species

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Margarida Maria Barros

2002-04-01

Full Text Available Este estudo foi realizado no Laboratório de Pesquisas em Nutrição de Organismos Aquáticos, da FMVZ - Unesp Campus de Botucatu, Estado de São Paulo, unidade integrada ao Centro de Aquicultura da Unesp. Teve por objetivo avaliar a influência do diâmetro do ingrediente alimentar (0,5; 1,0; 1,5; 2,0 e 2,5 mm, por meio da digestibilidade aparente de rações pela tilápia do Nilo, Oreochromis niloticus L. (Perciformes cichlidae, e pelo pacu, Piaractus mesopotamicus (Holmberg Characiformes, Characidae, com peso médio de 100,0 gramas. Foram determinados os coeficientes de digestibilidade aparente da matéria seca, proteína bruta e extrato etéreo. Estes tratamentos foram avaliados por meio de análise de variância em um esquema fatorial 2 x 5 (duas espécies de peixes e cinco diâmetros. Os resultados demonstram que existe interação significativa entre o diâmetro da partícula alimentar e a espécie, e que o diâmetro mais adequado da partícula para a confecção de rações apresenta-se entre 1,0 mm e 2,0 mm para o pacu e, de 1,5 mm para a tilápia do Nilo.This research was carried out at the Aquatic Organisms Nutrition Research Laboratory, FMVZ - Unesp - Campus of Botucatu, a unit of Aquaculture Center of Unesp (Universidade Estadual de São Paulo - Brazil. The objective was to evaluate the ingredient diameter influence (0.5; 1.0; 1.5; 2.0 and 2.5 mm, using the apparent digestibility of diets by Nile tilapia, Oreochromis niloticus L. (Perciformes cichlidae and pacu, Piaractus mesopotamicus (Holmberg Characiformes, Characidae. The coefficients were determined according to dry matter, crude protein and ether extract. These treatments were analyzed by variance analysis in the factorial design 2 x 5 (two fish species and five diameters. The result showed that there is significant interaction between ingredient diamater and species and that, the most appropriate ingredient diameter to manufacture fish diets is between 1.0 and 2.0 mm to pacu

Dietary shifts in Brycinus sadleri (Pisces : Characidae) from southern Lake Victoria

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Wanink, J.H.; Joordens, J.C.A.

2007-01-01

We studied the diet of Brycinus sadleri in Lake Victoria after extensive environmental changes during the 1980s. To check for diet expansion following these changes, as observed in some other fish species, we compared our results with data from the 1950s. Stomach contents were analysed in relation

A new species of Charax (Ostariophysi, Characiformes, Characidae from northeastern Brazil

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Erick Cristofore Guimarães

2018-02-01

Full Text Available Charax awa sp. n. is herein described from the Rio Mearim, Rio Munim and Rio Turiaçu basins, three coastal river basins of northeastern Brazil located between the Rios Gurupi and Parnaíba basins. These have a complex and still poorly known biogeographic history. This region is ecologically extremely relevant since it comprises three of the main Brazilian biomes, as well as, transition zones between them: Amazônia, Brazilian Cerrado and Caatinga. Therefore, this area has faunal and floristic representatives of these three biomes, which makes it particularly relevant in terms of ecology, biodiversity and conservation. Charax awa sp. n. possesses a relatively small orbital diameter (22.1–28.5 % HL, what distinguishes it from most of its congeners, except from C. notulatus and C. caudimaculatus. It differs from C. caudimaculatus by a longer snout, and from C. notulatus by the number of scales around the caudal peduncle, as well as by the number of vertebrae. The new species herein described differs from its geographically closely distributed congeners, C. leticiae, C. niger, and C. pauciradiatus mainly by the relative horizontal orbital diameter. It is a “small-eyed” species. In addition, C. awa sp. n. can be distinguished from C. leticiae by having a maxilla extending to the vertical line posterior to the pupil, near the posterior orbital margin and by having a lower humeral spot distance. It can be distinguished from C. pauciradiatus by more scale rows from the pelvic-fin origin to the lateral line and more scale rows from the dorsal-fin origin to the lateral line and it differs from C. niger by having more transverse scale rows in space from the humeral spot to the supracleithrum. In addition, it differs from C. pauciradiatus and C. niger by the absence of bony hooks on anal and pelvic-fins rays of adult males.

A eficácia do mentol como anestésico para tambaqui (Colossoma macropomum, Characiformes: Characidae Efficacy of menthol as an anesthetic for tambaqui (Colossoma macropomum, Characiformes: Characidae

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Michelle Ferreira Façanha

2005-01-01

Full Text Available Os anestésicos são importantes na piscicultura para reduzir o estresse e a mortalidade no manejo. Este trabalho tem como objetivo determinar a eficácia do mentol para tambaqui durante o manejo. Na primeira série de testes, foi examinado o efeito da concentração de anestésico sobre indução à anestesia e o estresse de tambaqui. Na segunda série de testes, foi avaliada a recuperação dos peixes após a exposição a uma concentração de 150 mg/L de mentol por diferentes tempos. Na terceira série, foi avaliada se a melhor concentração encontrada para juvenil (150 mg/L também era adequada para peixes maiores. A melhor concentração para uma anestesia cirúrgica foi 150 mg/L, pois o tempo de indução é rápido, porém a recuperação é significativamente mais demorada do que para as menores concentrações testadas. Para uma anestesia, com finalidade de biometria, a melhor concentração foi 100 mg/L. Nesta concentração o tempo de indução à anestesia é prolongado, porém o tempo de recuperação está dentro da faixa considerada adequada. O tempo de recuperação do tambaqui quando exposto a 150 mg/L é significativamente igual para 10, 20 e 30 minutos de anestesia. Os resultados obtidos mostram que o mentol é um anestésico eficiente para o tambaqui.Anesthetics are important in fish culture to reduce handling stress and mortality. The objective of this work is to investigate menthol as an anesthetic for tambaqui. In the first series of tests, fish were exposed to various concentrations of menthol to evaluate induction time and stress responses. The second series examined the effect of exposure period to menthol at 150 mg/L on recovery time. The third assessed the best dosage for juveniles in larger tambaqui. The best concentration for surgical anesthesia is 150 mg/L. At this concentration the induction time is short, but their recovery time is significantly longer than that for lower concentrations. For biometry procedures, the best concentration is 100 mg/L. At this concentration the induction time is prolonged, but the recovery time is within the desired period. Recovery time for fish exposed to 150 mg/L is equal for 10, 20 or 30 minutes of exposure. The results confirmed that menthol is an adequate anesthetic for tambaqui.

Trophic relationships between macroinvertebrates and fish in a pampean lowland stream (Argentina

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María V. López van Oosterom

2013-03-01

Full Text Available The diet and trophic relationships between the macroinvertebrates Phyllogomphoides joaquini Rodrigues Capítulo, 1992 and Coenagrionidae (Odonata, Chironomidae (Diptera, Diplodon delodontus (Lamarck, 1919 (Bivalvia: Hyriidae, and Pomacea canaliculata (Lamarck, 1822 (Gastropoda: Ampulariidae and the fishes Pimelodella laticeps Eigenmann, 1917 (Heptapteridae and Bryconamericus iheringii (Boulenger, 1887 (Characidae in a temperate lowland lotic system in Argentina were assessed on the basis of gut contents and stable-isotope analyses. The feeding strategies were analyzed by the AMUNDSEN method. Relative food items contribution for the taxa studied indicated a generalist-type trophic strategy. In macroinvertebrates, in general, the values of stable isotope confirmed the result of the analysis of gut contents. With the fish, stable-isotope analysis demonstrated that both species are predators, although B. iheringii exhibited a more omnivorous behaviour. These feeding studies allowed us to determine the trophic relationships among taxa studied. Detritus and diatoms were a principal source of food for all the macroinvertebrates studied. In La Choza stream the particulate organic matter is a major no limited food resource, has a significant influence upon the community.

Distribution of Agonostomus monticola and Brycon behreae in the Río Grande de Térraba, Costa Rica and relations with water flow

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Thiago Cotta Ribeiro

Full Text Available Fish monthly samples were made in three tributaries and in the main stream in order to study population dynamics and the influence of flow on abundance of Agonostomus monticola (Mugilidae and Brycon behreae (Characidae in the basin of Térraba River Basin (Costa Rica. Flow was seasonal in these rivers, with peak flow in October. Recruitment was different among the species, B. behreae recruited from January to June and A. monticola all year round with a peak in June-July and October-November. Juveniles were more abundant in smaller streams. Abundance was higher in general during low flow and low turbidity periods. The results suggest that the streams have an important role in the maintenance of both species in the ecosystem, where juveniles can use the streams as nursing habitats during their development, allowing these small streams to be considered as essential fish habitats. Also, it was determined that the increased volume and turbidity of water can significantly affect the proportion of adults and juveniles between the main river and its tributaries.

O uso de peixes como bioindicador ambiental em áreas de várzea da bacia amazônica

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Carlos Edwar C. Freitas

2009-08-01

Full Text Available O uso de bioindicadores pode constituir uma importante ferramenta para monitoramento ambiental, e para ecossistemas aquáticos o uso de espécies de peixes é bastante eficiente, pois são componentes comuns e de fácil amostragem, bem como podem apresentar diferentes estilos de vida e habitats durante seu ciclo de vida. Neste artigo utilizamos como critérios para a seleção das espécies indicadoras, as seguintes características: ser taxonomicamente bem definido e facilmente reconhecível por não-especialistas, apresentar distribuição geográfica ampla, ser abundante ou de fácil coleta, preferencialmente possuir tamanho médio/grande, apresentar baixa mobilidade e longo ciclo de vida, dispor de características ecológicas conhecidas e ter possibilidade de uso em estudos em laboratório. Desta forma, indicamos oito espécies de peixes típicos das várzeas amazônicas: Pellona castelneana, Potamorhina altamazonica, Prochilodus nigricans, Mylossoma duriventre, Pygocentrus nattereri, Serrasalmus rhombeus, Triportheus angulatus e liposarcus pardalis, para uso como bioindicadores em programas de monitoramento ou de avaliação de alterações ambientais.

Spermatic characteristics and sperm evolution on the subfamily Stevardiinae (Ostariophysi: Characiformes: Characidae

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Clarianna Martins Baicere-Silva

2011-06-01

Full Text Available The monophyly and phylogenetic relationships among the members of Clade A characids (sensu Malabarba & Weitzman, later redefined and named as the Stevardiinae (sensu Mirande, have been primarily supported by traditional morphological and molecular data. Herein were examined, described and compared spermiogenesis and sperm ultrastructure of 12 species of the genera Boehlkea, Bryconacidnus, Bryconamericus, Creagrutus, Cyanocharax, Hemibrycon, Knodus, Odontostoechus, Piabina, and Rhinobrycon in order to evaluate possible phylogenetic signals and their potential use in recovering relationships of the Stevardiinae. All examined species demonstrated a nuclear rotation equal or less than 95º resulting in a lateral position of the double nuclear fossa and flagellum. In all species, sperm nuclei are slightly elongate toward the flagellum, the proximal centriole is partially inside the nuclear fossa and lies anterior and oblique to the distal centriole, and the midpiece is short and strongly asymmetric. All species analyzed herein and other species previously examined for these systems in the Stevardiinae share homologous sperm characteristics as evidenced by spermiogenesis, further supporting the monophyly of this clade. Spermatozoa of the Stevardiinae further show three morphotypes (M1, M2, M3 of arrangement of centrioles, flagellum, nucleus and midpiece, hypothesized as successively derived in a series of transformation from the most basal morphotype (M1.A monofilia e filogenia dos membros do Clado A (sensu Malabarba & Weitzman, mais tarde redefinido e nomeado Stevardiinae (sensu Mirande, é suportada por dados morfológicos e moleculares. Aqui são examinadas, descritas e comparadas a espermiogênese e ultraestrutura do espermatozoide de 12 espécies dos gêneros Boehlkea, Bryconacidnus, Bryconamericus, Creagrutus, Cyanocharax, Hemibrycon, Knodus, Odontostoechus, Piabina e Rhinobrycon, a fim de avaliar possíveis sinais filogenéticos e seu uso potencial no estudo de relações filogenéticas em Stevardiinae. Em todas as espécies examinadas observa-se uma rotação nuclear igual ou menor que 95º, resultando em uma posição lateral da fossa nuclear dupla e do flagelo. Em todas as espécies o núcleo do espermatozoide é alongado em direção ao flagelo, o centríolo proximal é anterior e oblíquo ao centríolo distal e localiza-se parcialmente inserido na fossa nuclear, e a peça intermediária é pequena e fortemente assimétrica. Todas as espécies de Stevardiinae analisadas aqui e outras analisadas previamente compartilham características homólogas dos espermatozoides evidenciadas por sua espermiogênese, corroborando a monofilia deste clado. Os espermatozoides de Stevardiinae apresentam ainda três morfotipos (M1, M2, M3 de acordo com o arranjo dos centríolos, flagelo e peça intermediária, considerados como sucessivamente derivados em uma série de transformações a partir do morfotipo mais basal (M1.

Spermatic characteristics and sperm evolution on the subfamily Stevardiinae (Ostariophysi: Characiformes: Characidae

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Clarianna Martins Baicere-Silva

Full Text Available The monophyly and phylogenetic relationships among the members of Clade A characids (sensu Malabarba & Weitzman, later redefined and named as the Stevardiinae (sensu Mirande, have been primarily supported by traditional morphological and molecular data. Herein were examined, described and compared spermiogenesis and sperm ultrastructure of 12 species of the genera Boehlkea, Bryconacidnus, Bryconamericus, Creagrutus, Cyanocharax, Hemibrycon, Knodus, Odontostoechus, Piabina, and Rhinobrycon in order to evaluate possible phylogenetic signals and their potential use in recovering relationships of the Stevardiinae. All examined species demonstrated a nuclear rotation equal or less than 95º resulting in a lateral position of the double nuclear fossa and flagellum. In all species, sperm nuclei are slightly elongate toward the flagellum, the proximal centriole is partially inside the nuclear fossa and lies anterior and oblique to the distal centriole, and the midpiece is short and strongly asymmetric. All species analyzed herein and other species previously examined for these systems in the Stevardiinae share homologous sperm characteristics as evidenced by spermiogenesis, further supporting the monophyly of this clade. Spermatozoa of the Stevardiinae further show three morphotypes (M1, M2, M3 of arrangement of centrioles, flagellum, nucleus and midpiece, hypothesized as successively derived in a series of transformation from the most basal morphotype (M1.

Astyanax intermedius Eigenmann, 1908 (Actinopterygii: Characiformes: Characidae): Distribution extension in eastern Brazil

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Lezama, Antônio; Triques, Mauro; Queiroz, Federico

2011-01-01

Astyanax intermedius is known to occur at Paraíba do Sul River basin and coastal rivers of Rio de Janeiro state. A detailed study is presented in order to clearly assign the species to the Doce River basin, in Minas Gerais state.

Avaliação da predação de Podocnemis expansa e Podocnemis unifilis (Testudines, Podocnemididae no rio Javaés, Tocantins Evaluation of predation in Podocnemis expansa and Podocnemis unifilis (Testudines, Podocnemididae in the Javaés River, Tocantins

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Giovanni Salera Junior

2009-03-01

Full Text Available Podocnemis expansa e P. unifilis são animais de vida longa, com uma demorada maturação sexual, o que influencia uma baixa taxa de substituição de indivíduos. Suas populações são caracterizadas por uma pequena mortalidade dos animais adultos, mas alta taxa de mortalidade de filhotes e embriões. Sendo a predação natural de ninhos e filhotes um dos fatores mais importantes do baixo sucesso de eclosão dessas espécies. No rio Javaés, os ovos e recém-eclodidos podem ser predados por uma grande diversidade de animais: dentre as aves, urubus (Coragyps atratus e Cathartes aura, carcará (Polyborus plancus, jaburu (Jabiru mycteria; lagartos (Tupinambis teguixin e mamíferos de pequeno porte, coati (Nasua nasua e cachorro-do-mato (Cerdocyon thous. Do total anual de desovas de P. unifilis em média 65,98% são predadas, sendo 41,68% de forma total e 24,30% parcialmente. Enquanto que apenas 5,31% das ninhadas de P. expansa são sempre parcialmente predadas. Dentre os predadores aquáticos existem diversos peixes, principalmente piranhas (Serrasalmus nattereri e jacarés (Melanosuchus niger e Caimam crocodilus. Os predadores das fêmeas de P. unifilis são: jacaré-açu (Melanosuchus niger, onça-pintada (Panthera onca e onça-parda (Puma concolor. Enquanto que as fêmeas de P. expansa em postura, somente são predadas por P. onca. As fêmeas de P. unifilis em postura são predadas num total médio de 3,93% anualmente, enquanto que para P. expansa a média anual é 5,66% das fêmeas.Podocnemis expansa and P. unifilis long lived with late sexual maturation, which influences a low replacement rate of individuals. Their populations are characterized by low adults mortality, but high mortality of embryos and hatchlings. The natural nest predation is an important factor for hatchling success. In Javaés River, the eggs and hatchlings can be predated by a large number of animals such as birds, vultures (Coragyps atratus and Cathartes aura, carcar

Genetic differentiation in the populations of red piranha, Pygocentrus nattereri Kner (1860 (Characiformes: Serrasalminae, from the river basins of northeastern Brazil

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L. A. Luz

Full Text Available Abstract The red piranha, Pygocentrus nattereri, is an important resource for artisanal and commercial fisheries. The present study determines the genetic differentiation among P. nattereri populations from the northeastern Brazilian state of Maranhão. The DNA was isolated using a standard phenol-chloroform protocol and the Control Region was amplified by PCR. The PCR products were sequenced using the didesoxyterminal method. A sequence of 1039 bps was obtained from the Control Region of 60 specimens, which presented 33 polymorphic sites, 41 haplotypes, һ =0.978 and π =0.009. The neutrality tests (D and Fs were significant (P < 0.05 for most of the populations analyzed. The AMOVA indicated that most of the molecular variation (72% arises between groups. The fixation index was highly significant (FST = 0.707, P < 0.00001. The phylogenetic analyses indicated that the specimens represented a monophyletic group. Genetic distances between populations varied from 0.8% to 1.9%, and were <0.5% within populations. The degree of genetic differentiation found among the stocks of P. nattereri indicates the need for the development of independent management plans for the different river basins in order to preserve the genetic variability of their populations.

Phenacogaster apletostigma, nova espécie de peixe do Estado do Amapá, Brasil (Characiformes, Characidae Phenacogaster apletostigma, new species of fish from the Amapá State, Brazil (Characiformes, Characidae

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Zilda Margarete S. de Lucena

2007-03-01

Full Text Available Phenacogaster apletostigma sp. nov. distingue-se por apresentar uma grande mancha umeral verticalmente alongada que se estende desde a linha lateral até quase o dorso do corpo e apresenta um prolongamento na porção ântero-dorsal. Tanto a forma quanto o tamanho da mancha não são encontrados em nenhuma outra espécie do gênero e é aqui considerada uma autapomorfia da espécie. Habita o sistema do rio Araguari, no Estado do Amapá, Brasil.Phenacogaster apletostigma sp. nov. is distinguished from all other species of the genus by the presence of a large and vertically elongate humeral blotch, extending from the lateral line to near the dorsum. Anterodorsal portion of humeral blotch with an anterior extension. The unique shape and size of the humeral blotch, not found in the remaining Phenacogaster species, is considered an autapomorphy of the new species. It is known from the River Araguari basin, Amapá State, Brazil.

The ichthyofauna of drifting macrophyte mats in the Ivinhema River, upper Paraná River basin, Brazil

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Bulla, C. K.; Gomes, Luiz Carlos; Miranda, Leandro E.; Agostinho, A. A.

2011-01-01

We describe the fish assemblages associated with drifting macrophyte mats and consider their possible role as dispersal vectors in the Ivinhema River, a major tributary of the upper Paraná River, Brazil. Fish associated with drifting mats were sampled in the main river channel during January and March 2005, when the wind and/or the increased water level were sufficient to transport macrophyte stands. Fish in the drifting mats were sampled with a floating sieve (4 m long x 2 m wide x 0.6 m high, and 2 mm mesh size). In the laboratory, larvae, juvenile, and adult fish were counted and identified to the lowest possible taxonomic level. In four drifting macrophyte mats we captured 218 individuals belonging to at least 28 species, 17 families, and 6 orders. Aphyocharax dentatus, Serrasalmus spp., and Trachelyopterus galeatus were the most abundant taxa associated with the mats, but species richness ranged from 6 to 24 species per mat. In addition, 85% of the total number of individuals caught was larvae and juveniles. Although preliminary and based on limited samples, this study of drifting macrophyte mats was the first one in the last unregulated stretch of the Paraná River remaining inside Brazilian territory, and alerts us to the potential role of macrophytes mats as dispersers of fish species in the region.

Reproductive strategies and genetic variability in tropical freshwater fish

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Maria Dolores Peres Lassala

2007-01-01

Full Text Available We estimated the genetic variability of nine fish species from the Brazilian upper Paraná River floodplain (Astyanax altiparanae, Hoplias malabaricus, Leporinus lacustris, Loricariichthys platymetopon, Parauchenipterus galeatus, Pimelodus maculatus, Rhaphiodon vulpinus, Roeboides paranensis and Serrasalmus marginatus based on data for 36 putative allozyme loci obtained using corn starch gel electrophoresis of 13 enzymatic systems: aspartate aminotransferase (EC 2.6.1.1, acid phosphatase (EC 3.1.3.2, esterase (EC 3.1.1.1, glycerol-3-phosphate dehydrogenase (EC 1.1.1.8, glucose-6-phosphate dehydrogenase (EC 1.1.1.49, glucose-6-phosphate isomerase (EC 5.3.1.9, Iditol dehydrogenase (EC 1.1.1.14, isocitrate dehydrogenase - NADP+ (EC 1.1.1.42, L-lactate dehydrogenase (EC 1.1.1.27, malate dehydrogenase (EC 1.1.1.37, malate dehydrogenase-NADP+ (EC 1.1.1.40, phosphoglucomutase (EC 5.4.2.2 and superoxide dismutase, (EC 1.15.1.1. The mean expected heterozygosity varied from zero to 0.147. When data from the literature for 75 species of tropical fish were added to the nine species of this study, the heterozygosity values differed significantly among the groups of different reproductive strategies. The highest mean heterozygosity was for the non-migratory without parental care, followed by the long-distance migratory, and the lowest mean was for the non-migratory with parental care or internal fecundation.

The ichthyofauna of limnic systems in Quaternary deposits of extreme southern Brazil

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Cindy Marques

2016-12-01

Full Text Available The Quaternary in the state of Rio Grande do Sul (RS, southern Brazil, is geologically represented by the coastal plain and was originated by successive events of Pleistocene-Holocene marine transgressions and the occurrence of alluvial deposits. This paper aimed to characterize the fish assemblage occurring in a swampy Quaternary area adjacent to Lagoa Pequena, a lacustrine system connected to the west margin of the Laguna dos Patos estuary. A checklist is also provided of the ichthyofauna so far recorded in limnic systems of Quaternary deposits in the state of Rio Grande do Sul. A total of 42 species was recorded, distributed in nine orders, 18 families and 31 genera. Characidae and Cichlidae were the most representative families, comprising 15 and 4 species respectively. A bibliographic revision associated to our sample data revealed the occurrence of 156 species in limnic systems inserted in RS Quaternary deposits (114 limnic, 15 marine/estuarine/limnic, ten marine/estuarine, nine estuarine/limnic and eight marine. Characiformes and Siluriformes are the most diverse orders, corroborating the Neotropical pattern. Seven species can be considered endemic to RS Quaternary deposits.

Analysis by RAPD of the genetic structure of Astyanax altiparanae (Pisces, Characiformes in reservoirs on the Paranapanema River, Brazil

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Maria Sueli Papa Leuzzi

2004-01-01

Full Text Available In this study, the RAPD technique was used to analyze the genetic structure of populations of the fish Astyanax altiparanae (Characidae, Tetragonopterinae living in the lower, middle and upper Paranapanema River, Brazil. The aim was to assess this structure regarding fish handling and conservation programs. The genetic variability (P was found to be 42.64%, 75% and 75% in the low, middle and upper reaches, respectively. The dendrogram of genetic similarity, obtained by comparative analysis of the sets of samples from the three sites, showed the formation of three clusters. All of the genetic parameters used indicate that the population in the lower Paranapanema is genetically different from those in the middle and upper sections. The theta P test shows that the low Paranapanema is highly differentiated from the middle (0.2813 and upper (0.2912 Paranapanema, while the differentiation between the last two is moderate (0.0895. The data obtained in the present work suggest that recolonization and conservation studies should not be focused on the species A. altiparanae as such, but on the conservation units, because they are the genetically differentiated populations.

Plasma testosterone and 11-ketotestosterone levels of male pacu Piaractus mesopotamicus (Cypriniformes, Characidae

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R. Gazola

1997-12-01

Full Text Available The levels of testosterone (T and 11-ketotestosterone (11-KT of the South American pacu Piaractus mesopotamicus were determined by radioimmunoassay during two stages of the reproductive cycle, i.e., resting and maturation, and the gonadosomatic index (GSI was calculated. The highest levels of T and 11-KT were reached during the maturation stage (T = 2400 ± 56 pg/ml; 11-KT = 2300 ± 60 pg/ml and lower levels were maintained during the resting period. The rise in androgen levels occurred with the appearance of spermatozoa in the maturation stage, when GSI was highest

Three new species of Hemibrycon (Characiformes: Characidae from the Magdalena River Basin, Colombia

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César Román-Valencia

2013-09-01

Full Text Available Fish biodiversity of aquatic ecosystems is highly threatened by different economic activities driven by human populations, and its description is increasingly a priority. For the Cauca-Magdalena River system we have described 14 species, and the purpose of this paper was to describe three new species belonging to the same genus Hemibrycon from the Nare and Guatapé River drainages of the middle Magdalena River, Colombia. The description was based on a series of 200 specimens, and the use of morphometric, meristic and osteological characters, as well as fish distribution and morphogeometric analytical methods. We have found that Hemibrycon fasciatus n. sp. (n=54 differs from other species of Hemibrycon (that also have a vertical humeral spot in having: melanophores outlining the posterior margins of the scales along sides of body; humeral spot extending onto posterior margin of opercle; a dark lateral stripe, formed by deep pigment that is continuous with the peduncular spot; the toothed portion of the maxilla not reaching the dorsal margin of the dentary (vs. toothed portion of maxilla extending beyond dorsal margin of dentary; all maxillary teeth tricuspid (vs. some unicuspid teeth present on maxilla. H. cardalensis n. sp. (n=64 differs in having: a vertically elongate humeral spot that extends one or two scales below the lateral line canal. H. cardalensis n. sp. differs from all congeners in having the pigment of the caudal spot restricted to the ventral half of the caudal peduncle, and in having melanophores around the anterior scales of the lateral line. Hemibrycon antioquiae n. sp. (n=82 differs in having a circular humeral spot. It differs from the other species with a circular humeral spot, like H. mikrostiktos, in having a projection of disperse melanophores extending from the dorsal margin of the humeral spot to below the lateral stripe. Habitat data and environmental impacts caused by the construction of reservoirs for hydroelectric projects and other threats in the area are included, as well as a key to all species Hemibrycon present in the Magdalena River Basin. The synonymy of H. pautensis with H. polyodon is discussed and H. pautensis is evalidated.

Molecular phylogeny and biogeographic history of the Neotropical tribe Glandulocaudini (Characiformes: Characidae: Stevardiinae

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Priscila Camelier

2018-03-01

Full Text Available ABSTRACT Although former studies on systematics and biogeography represent a progress on the knowledge of the tribe Glandulocaudini, none was grounded on molecular evidence. Thus, the first hypothesis of relationships for the tribe based on a multilocus analysis is presented, including all genera and most of the valid species. DNA sequences of Glandulocauda caerulea and Mimagoniates sylvicola were analyzed for the first time. A molecular clock analysis was used to estimate the origin of the Glandulocaudini and the approximate timing of cladogenetic events within the group. Glandulocaudini was recovered as monophyletic. No hypothesis recovered Glandulocauda as monophyletic, since G. melanopleura is sister to Lophiobrycon weitzmani while G. caerulea is closely related to Mimagoniates. The relationships within the latter genus were resolved. The molecular clock results indicate the origin of the Glandulocaudini during the Miocene with diversification in the group occurring from Neogene to Pleistocene. These results corroborated the hypothesis that its origin took place on the Brazilian crystalline shield with the subsequent occupation of the Atlantic Coastal drainages. Apparently, Pleistocene sea-level fluctuations might have shaped the distribution pattern of some species in Glandulocaudini.

Testicular maturation of Oligosarcus hepsetus (Cuvier (Actinopterygii, Characidae in a brazilian tropical reservoir

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R. N. Santos

Full Text Available Six reproductive classes of male Oligosarcus hepsetus (Cuvier, 1829, a medium-sized carnivorous Characiform species, are described based on macroscopic and histological techniques. A total of 175 individuals were caught monthly between April 2001 and June 2002 in the Lajes Reservoir, Brazil, one of the largest impoundment areas in the state of Rio de Janeiro. The reproductive classes were based upon changes in the testicular morphology and stages of germinative cells, i.e., resting, early maturing, late maturing, mature, partially spent and totally spent. Fish in the resting class showed testes with spermatogonia and spermatocytes along the wall of seminal lobules, while spermatids were present in the lumina of the lobules. During early maturing, active spermatogenesis occurs throughout the testis; in the late maturing and mature classes, the lobules are swollen with sperm that are typical of fish in breeding condition. Spent testes presented seminal lobules with residual spermatozoa, coinciding with decreasing GSI and greatly reduced sperm production. Overall, the testicular morphology and class of maturity development of O. hepsetus in the Lajes reservoir did not differ significantly from those of closely related species in other lentic environments. Lower GSI values in the oligotrophic Lajes reservoir than in other eutrophic natural lakes suggest that this species may be modifying this aspect of its reproductive strategy in response to the artificial environment.

Primeiro registro da utilização medicinal de recursos pesqueiros na cidade de São Félix, Estado da Bahia, Brasil - DOI: 10.4025/actascibiolsci.v27i2.1328 First account on the use of fishing resources as medicines in the city of São Félix, Bahia State, Brazil - DOI: 10.4025/actascibiolsci.v27i2.1328

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Juliana Nascimento Andrade

2005-03-01

Full Text Available Este trabalho discute a utilização medicinal de recursos pesqueiros pelos moradores da cidade de São Félix, Estado da Bahia. O trabalho de campo foi realizado entre maio de 2004 a março de 2005, entrevistando-se 29 indivíduos de ambos os sexos com idades que variaram de 11 a 79 anos. As informações foram obtidas junto a pescadores e a suas famílias por meio de entrevistas abertas e semi-estruturadas. A maior parte das entrevistas foi gravada, usando-se micro-gravador, sempre com o consentimento dos informantes. As transcrições feitas em caderno de campo encontram-se mantidas no Laboratório de Etnobiologia da Universidade Estadual de Feira de Santana, Estado da Bahia. Espécimes de peixes foram coletados, identificados e depositados no Laboratório de Ictiologia da UEFS. Os resultados mostram que, no sistema de classificação etnoictiológico dos pescadores de São Félix, diferentes organismos não sistematicamente relacionados são incluídos no domínio etnozoológico “Peixe”. Por essa razão, sete etnoespécies de peixes foram citadas como recursos medicinais: bagre (Genidens genidens, camarão (Macrobrachium sp., cambotá (Callichthys sp., piau (Leporinus sp., piranha (Serrasalmus branditi, peixe-boi (Trichechus sp. e traíra (Hoplias malabaricus. Esses animais fornecem matérias-primas que são utilizadas na elaboração de medicamentos que visam tratar e/ou curar enfermidades diagnosticadas localmente. O registro escrito da medicina tradicional implica conservação da cultural local, além de permitir que os recursos zooterapêuticos possam ser avaliados quanto à provável existência de compostos biologicamente ativosThis article deals with the medicinal use of fishing resources by the inhabitants of São Félix, Bahia State. Fieldwork was carried out from May 2004 to March 2005 by interviewing 29 individuals of both sexes, whose ages ranged from 11 to 79 years old. Data were obtained by means of open-ended interviews

The ichthyofauna of drifting macrophyte mats in the Ivinhema River, upper Paraná River basin, Brazil

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Cíntia Karen Bulla

2011-06-01

Full Text Available We describe the fish assemblages associated with drifting macrophyte mats and consider their possible role as dispersal vectors in the Ivinhema River, a major tributary of the upper Paraná River, Brazil. Fish associated with drifting mats were sampled in the main river channel during January and March 2005, when the wind and/or the increased water level were sufficient to transport macrophyte stands. Fish in the drifting mats were sampled with a floating sieve (4 m long x 2 m wide x 0.6 m high, and 2 mm mesh size. In the laboratory, larvae, juvenile, and adult fish were counted and identified to the lowest possible taxonomic level. In four drifting macrophyte mats we captured 218 individuals belonging to at least 28 species, 17 families, and 6 orders. Aphyocharax dentatus, Serrasalmus spp., and Trachelyopterus galeatus were the most abundant taxa associated with the mats, but species richness ranged from 6 to 24 species per mat. In addition, 85% of the total number of individuals caught was larvae and juveniles. Although preliminary and based on limited samples, this study of drifting macrophyte mats was the first one in the last unregulated stretch of the Paraná River remaining inside Brazilian territory, and alerts us to the potential role of macrophytes mats as dispersers of fish species in the region.Nesse trabalho as assembleias de peixes associadas a bancos de macrófitas flutuantes à deriva foram descritas. Além disso, foi considerado o possível papel desses bancos como vetores de dispersão no rio Ivinhema, importante tributário do alto rio Paraná, Brasil. Os peixes associados aos bancos à deriva foram amostrados no canal principal desse rio, entre os meses de Janeiro a Março de 2005, quando o vento e/ou o aumento no nível da água foram suficientes para transportar os bancos de macrófitas. Os peixes foram amostrados com uma rede flutuante (4 m de comprimento x 2 m de largura x 0,6 m de altura e 2 mm de tamanho de malha. No

Comparative cytogenetics in Astyanax (Characiformes: Characidae with focus on the cytotaxonomy of the group

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Renata Cristina Claudino de Oliveira Tenório

Full Text Available Astyanax is a diverse group of Neotropical fishes, whose different forms occupy different environments. This great diversity is also reflected on cytogenetic aspects and molecular markers, which have repeatedly been demonstrated by cytogenetic studies. In order to characterize the karyotype of species of this genus, six species were studied: Astyanax altiparanae, A.argyrimarginatus, A. elachylepis, A. xavante, and two new species provisionally called Astyanax sp. and A. aff. bimaculatus. A detailed cytogenetic study based on conventional staining with Giemsa, AgNORs, C-banding, base-specific fluorochromes, and FISH using ribosomal genes 18S and 5S was conducted, aiming to understand some of the chromosomal mechanisms associated with the high diversification that characterizes this group and culminated with the establishment of these species. The results showed 2n = 50 chromosomes for five species and a karyotype with 52 chromosomes in Astyanax sp. Small variations in the macrostructure of the karyotypes were identified, which were quite relevant when analyzed by classical banding, fluorochromes, and FISH methods. These differences among Astyanax spp. (2n = 50 are largely due to changes in the amount and types of heterochromatic blocks. Astyanax sp (2n = 52, in addition to variations due to heterochromatic blocks, has its origin possibly by events of centric fission in a pair of chromosomes followed by minor rearrangements.These results show an interesting karyotypic diversity in Astyanax and indicate the need of a review of the group referred as A. aff. bimaculatus and the description of Astyanax sp., including the possibility of inclusion of this unit in another genus.

Paraoxonase activity in sera from Piaractus mesopotamicus Holmberg (Characidae and Hypostomus punctatus Valenciennes (Siluridae

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Vera Lucia F. Cunha Bastos

1998-01-01

Full Text Available A paraoxonase activity present in serum of two Brazilian fish species was consistently assayed at pH 8.5 using 7.5 mM paraoxon final concentration. The paraoxonase activity was more activated by 0.5 M NaCl in serum of Piaractus mesopotanricus Holmberg, 1887 (pacu than in serum of Hypostomus punctatus Valenciennes, 1840 (cascudo. Apparent values of K M were 3.3 x 10-3 M for cascudo and pacu paraoxonase activity in the presence of 0.5 M NaCl. Apparent maximum velocity values calculated in the presence of 0.5 M NaCl were 6.1 and 6.5 nmole/min/mL of serum for cascudo and pacu, respectively. Vmax/K M ratio values of determinations in the presence and absence of 0.5 M NaCl showed that NaCl had a more evident effect on increasing the affinity of serum paraoxonase for paraoxon in pacu serum. Young specimens of pacu showed a marked decreased paraoxonase serum activity when kept in tanks treated with 0.25 ppm methyl-parathion.

Parasitism by Monogenoidea in Piaractus mesopotamicus (Characiformes, Characidae cultivated in Paraná River (Brazil

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M. S. L. Leão

2017-05-01

Full Text Available Abstract This study investigated the occurrence, prevalence, mean abundance and mean intensity of monogenoidean parasites in Piaractus mesopotamicus farmed in cages in the reservoir of the Itaipu Hydroelectric Power Station, Paraná River, Brazil. The parasite distribution pattern and the correlation of prevalence and abundance with the total length of hosts were also investigated. Four monogenoidean species were collected: Anacanthorus penilabiatus, A. toledoensis, Mymarothecium ianwhitingtoni and M. viatorum. All the parasites collected in P. mesopotamicus showed the typical aggregated distribution pattern, and the abundance and the prevalence did not shown any correlation with the total length of hosts.

Seasonal diet shift in a Tetragonopterinae (Oateichthyes, Characidae from the Ubatiba river, RJ, Brazil

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Mazzoni R.

2003-01-01

Full Text Available In the present study, we describe feeding habits of Deuterodon sp. from the Ubatiba River and explore if diet changes according to a temporal cycle of dry and wet seasons. We observed that Deuterodon sp. fed on an extremely high diversity of items ranging from organic matter, sediment (sand plus quartz parts, algae, seeds and leaves to animal organisms, such as, crustaceans, oligochaets and several life stages of terrestrial and aquatic insects, indicating an omnivorous diet. An important shift in the use of feeding resources was also registered; animal and vegetal items had alternated importance between both seasons. Allochthonous vs. autochthonous items analysis showed predominance of allochthonous items during dry season while no significant differences were registered during wet season.

A new species of Bryconops (Teleostei: Characidae from the rio Madeira basin, Northern Brazil

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Juliana M. Wingert

Full Text Available A new species of Bryconops is described from a tributary to the rio Madeira in the Amazon basin, State of Rondônia, Brazil. Bryconops piracolina belongs to the subgenus Bryconops by having no teeth or rarely one tooth in the maxilla, and a naked area on cheek between the second and third infraorbitals. The new species is distinguished from all species of this subgenus by the presence of a large black blotch on dorsal-fin base. Furthermore, it is distinguished from all congeners, except B. inpai, by possessing the adipose fin entirely black. It differs from B. inpai by the lack of humeral spots. It further differs from all species of the subgenus Bryconops, except B. caudomaculatus, by having the last scales of the longitudinal series of scales that bears the lateral line series not pored beyond the end of the hypural plate, and differs from B. caudomaculatus by the smaller number of pored lateral line scales (31-36, mean 34.6, vs. 37-43, mean = 40.6, respectively.

Morfología de las especies de Hyphessobrycon (Characiformes: Characidae, grupo heterorhabdus, en Colombia

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Carlos A. García-Alzate

2011-06-01

Full Text Available El género Hyphessobrycon incluye dieciocho especies reportadas para Colombia de las cuales 13 son miembros del grupo heterorhabdus; con las mismas, se realizó un análisis morfogeométrico por medio del Método de Cerchas (Box Truss y Láminas Delgadas (TPS. Se usaron 13 hitos homólogos tipo I y tres tipo II. El resultado del análisis cluster, llevado a cabo con cada una de las metodologías indicó que estas especies están representadas en dos grandes grupos: robustas y delgadas. Las deformaciones parciales, los componentes uniformes, no uniformes, Warps principales y Warps parciales describieron cambios de la forma relacionados con la profundidad del cuerpo e involucraron desplazamientos relativos del esqueleto apendicular y de la región cefálica. Todas las especies se caracterizan por presentar crecimiento alométrico excepto Hyphessobrycon mavro con isometría entre los hitos 6-7. Se plantean dos nuevas medidas discriminantes (hocico-supraoccipital y supraoccipital-aleta pélvica para las especies del grupo.

New Astyanax from the upper rio Tapajós drainage, Central Brazil (Characiformes: Characidae

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Vinicius A. Bertaco

Full Text Available Astyanax utiariti, new species, is described from the upper rio Tapajós drainage, Mato Grosso, Brazil. Astyanax utiariti has a horizontally oval black humeral spot, a lozenge-shaped caudal-peduncle spot, continuing to the tip of the middle caudal-fin rays, and two brown bars in the humeral region that allows its inclusion in the A. bimaculatus species group. It also possesses a black stripe extending along midlateral body. The new species is distinguished from its congeners by a reticulate scale pattern, a black longitudinal stripe, toothless maxilla, larger dentary teeth and teeth of the inner row of the premaxilla with five to seven cusps, body depth 33.3-39.9% of standard length (SL, head length (HL 23.9-26.4% of SL, caudal-peduncle depth 12.0-13.4% of SL, orbital diameter 28.5-34.3% of HL, interorbital width 32.7-38.4% of HL, 36-38 perforated scales along the lateral line, and 22-26 branched anal-fin rays.

Chrysobrycon yoliae, a new species of stevardiin (Characiformes: Characidae from the Ucayali basin, Peru

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James Anyelo Vanegas-Ríos

Full Text Available Chrysobrycon yoliae, new species, is described from a drainage flowing into the río Yucamia basin, río Ucayali basin, Peru. Chrysobrycon yoliaeis readily distinguished from its congeners by the anterior tip of pelvic bone situated anterior to the fifth rib (vs. situated posterior to the fifth rib, the presence of 20-26 dentary teeth (vs. 11-19, and the possession of a terminal lateral-line tube between caudal-fin rays 10 and 11 (vs. the absence of this tube, except in C. eliasi. The new species differs from C. eliasiand C. myersiby the presence of teeth on third pharyngobranchial (vs. the absence of teeth on this bone and also differs from C. eliasiby the dorsal-fin origin situated at vertical through anal-fin rays 5 to 7 (vs. located at vertical through anal-fin rays 8 to 10, the posterior extent of the ventral process of quadrate reaching the vertical through posterior margin of symplectic (vs. not reaching the vertical through posterior margin of symplectic, the dorsal-fin to adipose-fin length 26.8-28.8% SL (vs. 23.9-26.8% SL, and the body depth at dorsal-fin origin 34.4-42.2% SL (vs. 24.1-34.5% SL. A key for the identification of Chrysobryconspecies is provided.

A new species of Moenkhausia Eigenmann (Characiformes: Characidae from the rio Xingu basin, Brazil

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Manoela M. F. Marinho

Full Text Available A new species of Moenkhausia from the upper rio Xingu basin is described. Moenkhausia eurystaenia is distinguished from all congeners, except M. heikoi and M. phaeonota, by the presence of a dark, broad longitudinal stripe from the opercle to the end of caudal peduncle. The new species is distinguished from M. heikoi mainly by having 18-21 branched anal-fin rays (vs. 24-26 and the absence of a round blotch at the end of the caudal peduncle (vs. present. Moenkhausia eurystaenia can be distinguished from M. phaeonota mainly by the anterior portion of longitudinal band darker at horizontal septum (vs. darker below horizontal septum, the deep dark pigmentation along horizontal septum extending anteriorly up to humeral region (vs. extending up to vertical through pelvic-fin origin, number of vertebrae 34 (vs. 36-37, and others additional measurements.

Anatomy of the bucco-pharyngeal cavity of Salminus brasiliensis (Cuvier, 1817 (Pisces, Characidae, Salmininae

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Eliane Menin

2006-03-01

Full Text Available The bucco-pharyngeal cavity of Salminus brasiliensis, an ichthyophagous species of fresh water, is anatomically adapted to predation. The wide buccal rift, the oral-aboral enlargement of the buccal cavity and the reduced thickness of the pharyngeal mastigatory apparatus favor the capture and deglutition of larger prey. In function of the oral and pharyngeal dentition type, pre-digestive food preparation does not occur. The pointed and curved teeth, together with the tongue which is relatively mobile, prevent the prey’s escape from the buccopharyngeal cavity. The passage of the food is facilitated by the absence of pronounced folds in the mucous membrane of this cavity and by the disposition of the oral and pharyngeal teeth. The characteristics of flat and thin lips, developed oral dentition, relatively mobile tongue, mucous membrane without folds, pharynx with denticules disposed in dentigerous areas and plates, and short and sharp gill-rackers are anatomical adaptations which are shared by S. brasiliensis and other ichthyophagous Characiformes species such as Salminus maxillosus, Salminus hilarii, Hoplias malabaricus, Hoplias lacerdae, Acestrorhynchus lacustris and Acestrorhynchus britskii. However, different to the mentioned species, except other Salmininae, S. brasiliensis possesses oral teeth of an unique type, present only in the jawbones and distributed in two series.

Diet of Astyanax species (Teleostei, Characidae in an Atlantic Forest River in Southern Brazil

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Fábio Silveira Vilella

2002-06-01

Full Text Available Feeding habits of six species of Astyanax from river Maquiné are described. Fishes were sampled bi-monthly from November/95 to September/96 in two zones of the river. Items were identified, counted and had their abundance estimated according to a semi-quantitative scale. Frequency of occurrence, alimentary importance index (IFI values and a similarity analysis of diets for each species-river zone sample were examined. All the species were considered typically omnivorous, with insects and vegetal matter being the most important items in their diet. These species could act as seed dispersers, particularly for macrophytes. Intra-specific spatial differences were not observed in comparisons of samples from two diferent regions of the river, except for A. fasciatus. The presence of Podostemaceae macrophytes in the mid-course of the river seemed to be important both as an autochthonous food resource and as habitat for several organisms preyed by the Astyanax species.Seis espécies do gênero Astyanax, presentes no rio Maquiné, RS, foram estudadas quanto aos seus hábitos alimentares. Os exemplares foram amostrados bimensalmente de novembro de 1995 a setembro de 1996 nas zonas ritral e potamal do rio. Os itens alimentares foram identificados e quantificados de acordo com uma escala semi-quantitativa de abundância, utilizando-se para análise a frequência de ocorrência e um índice de importância alimentar para cada espécie e zona do rio. Análises multivariadas de agrupamento e ordenação foram utilizadas para comparar as dietas intra e interespecíficas. Todas as espécies foram consideradas onivoras, sendo que os itens mais importantes foram os insetos e restos de vegetais superiores. Sugere-se que as espécies estudadas possam atuar como dispersoras de sementes, particularmente para macrófitas. Diferenças espaciais intraespecíficas não foram encontradas, exceto para A. fasciatus. A presença de Podostemaceae no curso médio do rio parece ser uma fonte importante de alimento para as espécies, além de servir de refúgio para diversos organismos que são predados por Astyanax sp.

The Pet Trade as a Source of Invasive Fish in Taiwan

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Shih-Hisung Liang

2006-06-01

Full Text Available In this study, ornamental fish available for purchase at pet stores in Taiwan were compared to those documented as having invaded the island’s ecosystems. In total, 293 pet fish species belonging to 48 families were recorded. The top five families that included the most pet fish species were the Cichilidae (79 species, Callichthyidae (38, Characidae (37, Cyprinidae (20, and Loricariidae (16. Among the 48 families, five families, documented as having invasion records, are the Cichilidae, Cyprinidae, Loricariidae, Belontiidae, and Poeciliidae. Except for the Cichilidae, the proportion of invasive species to total species of other four families were at least equal to or greater than 10%, with the Belontiidae displaying the highest proportion at 66.6%. The Belontiidae also demonstrated a significantly higher rate of documented invasive species than did the other families. Families with a greater number of recorded pet fish species also presented a significant positive correlation with their documented invasive species if the 20 families with only a single surveyed species were excluded. Forcing retailers to foster home program, urging aquariums to display how to eliminate fish escaping from captivity, and instituting a higher custom duty or higher purchasing tax were proposed to eliminate future introductions of pet fish species.

Morfologia do trato digestório e dieta de larvas de Bryconamericus aff. iheringii (Boulenger, 1887 (Osteichthyes, Characidae = Morphology of Digestive tract and diet of Bryconamericus aff. iheringii larvae (Boulenger, 1887 (Osteichthyes, Characidae

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Renato Ziliani Borges

2006-01-01

Full Text Available Este trabalho teve como objetivo analisar alguns aspectos da alimentação de larvas de Bryconamericus aff. iheringii, capturadas nos meses de julho e novembro de 2001, nas regiões limnética e litorânea do reservatório de Santa Maria, rio Piquiri, Estado do Paraná. As larvas apresentaram boca subterminal durante todo o seu desenvolvimento. O tubo digestório se diferenciou em estômago e intestino apenas no estágio de pós-flexão. As larvas consumiram, principalmente, algas e microcrustáceos, o que permitiu caracterizá-las como planctófagas. A intensa modificação morfológica no trato digestório nos indivíduos em pósflexão coincidiu com o aumento na abundância de algas em relação aos itens de origemanimal; porém, de forma geral, a ocorrência aumentou para todos os itens. A análise do grau de digestão dos itens alimentares sugeriu que indivíduos em pré-flexão alimentaram-se, possivelmente, durante o dia, e os mais desenvolvidos, durante o entardecer e no períodonoturno.The aim of this study was to analyze some feeding treats of Bryconamericus aff. iheringii larvae, sampled in both the limnetic and littoral regions of the Piquiri River, in Santa Maria reservoir, between July and November 2001. The larvae presented sub-terminal mouth in larval period. The digestive tract differentiated in terms of stomach and intestine only in the postflexion larvae. The larvae fed mainly on algae and microcrustacea allowing to characterize them as planktivorous. The intense morphologic shift in the digestive tract in the postflexion larvae coincided with an increase in the abundance of algae in relation to animals items; however, in general, all the items had their occurrence increased. Analysis of the digestion stage suggested that preflexion larvae, possibly, fed themselves during the day, and those more developed, at dusk and night.

EFFECTS OF AQUATIC VEGETATION ON THE SPATIAL DISTRIBUTION OF GRUNDULUS BOGOTENSIS, HUMBOLDT 1821 (CHARACIFORMES: CHARACIDAE

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RIVERA-RONDÓN CARLOS ALBERTO

2008-07-01

Full Text Available G. bogotensis has a geographic distribution restricted to the Colombian Cundiboyacenseplateau, it is listed as near threatened, and research on its autoecology is scarce. Threecollections were made in 2006 in the Fúquene Lake, Cundinamarca, Colombia (5°27’ 55’’ N, 75° 46’ 19’’ W to describe the habitats occupied by G. bogotensis and todetermine its vertical and horizontal distribution. Three sampling zones were selectedaccording to the type of dominant macrophyte (Eichornia crassipes, Schoenoplectussp. and Egeria densa. In each sampling zone two different cylindrical sampling traps(cloth and PVC were placed at three depths: surface, mid-depth and bottom. Threereplicates were used for each depth and type of trap. Traps were exposed for 24 hoursand checked every 6 hours. In addition to the traps, sampling by electrofishing wasconducted in each sampling zone during every month. To characterize the study area,physical and chemical variables were analyzed and the structure of phytoplankton,zooplankton, periphyton, and macroinvertebrate communities was studied. Resultsshowed spatial differences on G. bogotensis habitat occupation and differences incaptures at each depth, which depend on the dominant type of aquatic vegetationand size of individual. We conclude that only cylindrical cloth traps are suitable toconduct population studies of G. bogotensis

Patterns of oocyte development in natural habitat and captive Salminus hilarii Valenciennes, 1850 (Teleostei: Characidae).

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Honji, R M; Narcizo, A M; Borella, M I; Romagosa, E; Moreira, R G

2009-03-01

Fecundity and oocyte development in Salminus hilarii female brood stock were analyzed with the aim of investigating the impact of migration impediment on oogenesis. Histological analyses of the ovaries were performed in adult females caught in two different environments--the Tietê River (natural) and captivity--and the gonadossomatic index, oocyte diameter and fecundity determined. Five germ cell development stages (oogonium, perinucleolar, cortical alveoli, vitellogenic, ripe) and two other structures (postovulatory follicles and atretic oocytes) were observed in females caught in the river. Captive animals lacked the ripe oocytes and postovulatory follicles and had a relatively higher number of atretic oocytes. Females in captivity are known to produce larger oocytes, and they release fewer eggs in each spawn (absolute fecundity) when compared with animals that are able to migrate. Our results suggest that the Tietê River is undergoing alterations which are being reflected in the reproductive performance of S. hilarii, mainly due to the presence of atretic oocytes in females caught in the river. The lack of postovulatory follicles and ripe oocytes in captive animals reveals that migratory impediment negatively impacts final oocyte maturation. However, the stage of maturation reached is adequate for ovulation induction with hormone manipulation.

Spatial and temporal variations' of characidae habitat, case study in Abras de Mantequilla wetland, Ecuador

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Alvarez Mieles, M.G.; Corzo, G.; Irvine, K.; Mynett, A.E.

2015-01-01

A central component of predictive ecology in wetlands is the analysis of species distribution as a function of their biotic and abiotic environment. This analysis is normally used by decision-makers in biodiversity conservation, species monitoring and environmental planning, among others. Habitat

Revision of the Astyanax orthodus species-group (Teleostei: Characidae with descriptions of three new species

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Raquel I. Riuz-C

2018-02-01

Full Text Available The Astyanax orthodus species-group includes nine species: Astyanax boliviensis sp. nov., A. bopiensis nom. nov., A. embera sp. nov., A. gandhiae sp. nov., A. moorii comb. nov., A. orthodus, A. superbus, A. villwocki and A. yariguies comb. nov. The group is diagnosed by the presence of a series of pinnate-shaped marks (chevrons located along the lateral midline, which extends from the humeral region to the caudal peduncle. Astyanax bopiensis nom. nov. is proposed as a substitute name for Astyanacinus multidens, which, along with Astyanax yariguies comb. nov., we reassign to Astyanax.We also propose the synonymy of Astyanacinus with Astyanax. The members of the A. orthodus species-group are distributed in northwestern South America, occurring in the Patia River drainage (A. embera sp. nov. of the Pacific coast of Colombia, the Atrato River Basin (A. orthodus, the Magdalena River Basin (A. yariguies comb. nov. of Caribbean Colombia, streams of the southern flank of the Andes of the Orinoco Basin in Venezuela (A. superbus, in the upper Amazon River Basin of Colombia, Ecuador and Peru (A. villwocki, A. gandhiae sp. nov., from the upper Paraguay River (A. moorii comb. nov., the Madidi and Mamore Rivers, Bolivia (A. boliviensis sp. nov. and A. bopiensis nom. nov.. All species currently included in Astyanacinus are reassigned to the Astyanax orthodus species-group.

Identification and chromosome mapping of repetitive elements in the Astyanax scabripinnis (Teleostei: Characidae) species complex.

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Barbosa, Patrícia; de Oliveira, Luiz Antonio; Pucci, Marcela Baer; Santos, Mateus Henrique; Moreira-Filho, Orlando; Vicari, Marcelo Ricardo; Nogaroto, Viviane; de Almeida, Mara Cristina; Artoni, Roberto Ferreira

2015-02-01

Most part of the eukaryotic genome is composed of repeated sequences or multiple copies of DNA, which were considered as "junk DNA", and may be associated to the heterochromatin. In this study, three populations of Astyanax aff. scabripinnis from Brazilian rivers of Guaratinguetá and Pindamonhangaba (São Paulo) and a population from Maringá (Paraná) were analyzed concerning the localization of the nucleolar organizer regions (Ag-NORs), the As51 satellite DNA, the 18S ribosomal DNA (rDNA), and the 5S rDNA. Repeated sequences were also isolated and identified by the Cot - 1 method, which indicated similarity (90%) with the LINE UnaL2 retrotransposon. The fluorescence in situ hybridization (FISH) showed the retrotransposon dispersed and more concentrated markers in centromeric and telomeric chromosomal regions. These sequences were co-localized and interspaced with 18S and 5S rDNA and As51, confirmed by fiber-FISH essay. The B chromosome found in these populations pointed to a conspicuous hybridization with LINE probe, which is also co-located in As51 sequences. The NORs were active at unique sites of a homologous pair in the three populations. There were no evidences that transposable elements and repetitive DNA had influence in the transcriptional regulation of ribosomal genes in our analyses.

Estudio Histológico del Tracto Digestivo del Neón Cardenal Paracheirodon axelrodi (Characidae)

OpenAIRE

Gómez-Ramírez, E; Obando, M. J; Tovar, M. O; Caldas, M. L; Hurtado, H

2011-01-01

Paracheirodon axelrodi es el pez ornamental que más se exporta en Colombia. Sin embargo, se desconocen varios aspectos de su biología básica. Se estudió la histología del tracto digestivo. Se sacrificaron 15 ejemplares (MS 222, 0,5 g/L), fijados en formaldehído al 4 % y decalcificados con ácido nítrico 7 %. Se siguió el procedimiento para H&E. El tracto digestivo de P. axelrodi presentó cuatro capas constitutivas: mucosa, submucosa, muscular y serosa. La mucosa de la boca presentó un epitelio...

DESCRIPCIÓN MORFOLÓGICA DEL TUBO DIGESTIVO DE JUVENILES DE RUBIO Salminus affinis (PISCES: CHARACIDAE

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VJ Atencio

2008-09-01

Full Text Available El objetivo del estudio fue la descripción del tubo digestivo de juveniles de Rubio Salminus affinis. Se analizaron cinco juveniles con 23,6±2,6 cm de longitud total y 142,8±62,5 g de peso. Se realizó descripción topográfica y morfológica de los órganos y cortes histológicos con tinción H-E. El esófago es un órgano tubular corto de pared gruesa que representa el 7,8% de la longitud total del tubo digestivo, presenta pliegues internos que ofrecen gran capacidad de distensión permitiendo el paso de presas de gran tamaño. El estómago es una bolsa asimétrica en forma de “Y”, grande y musculosa, amplio en la porción anterior y estrecho hacia el fondo; el número de ciegos pilóricos varió entre 13 y 23 pudiendo ser monotubulares y ramificados. El intestino, con tres asas, se extiende desde el esfínter pilórico hasta el ano. Histológicamente el tubo digestivo está formado por cuatro capas: mucosa, submucosa, muscular y serosa; el epitelio de revestimiento del esófago es estratificado plano no queratinizado con células caliciformes, cambiando a simple cilíndrico mucosecretor llegando al estómago; en el estómago se encuentra epitelio simple cilíndrico mucosecretor y los ciegos pilóricos e intestino son revestidos por epitelio simple cilíndrico con células caliciformes. Tanto el valor promedio del coeficiente intestinal (0,58, como la pared distensible del estómago sugieren que el Rubio tiene un tubo digestivo propio de carnívoro y sus características histológicas presentan similitud con la mayoría de vertebrados superiores.

Checklist comparison and dominance patterns of the fish fauna at Taim Wetland, South Brazil

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Alexandre M. Garcia

Full Text Available Taim Hydrological System is a unique subtropical wetland in southern Brazil harboring an exceptional biological diversity. In 1978, an ecological reserve was established to protect part of this area from increasing anthropogenic impacts in its surroundings. Fishes have been poorly investigated in this system. Based on a multi-gear sampling study encompassing several years (2001-2005, and on comparisons with previous fish inventories, we provide an up-to-date species list of fishes occurring in the Taim Wetland. In addition, we made the first preliminary description of fish dominance patterns found in the main lakes of the system (Flores, Nicola, Jacaré and Mangueira. Checklist comparison resulted in 62 fish species distributed in 24 families, with Characidae (19 species and Cichlidae (7 showing the highest species richness. Six species are cited for the first time in the reserve: Trachelyopterus lucenai (Auchenipteridae, Hoplosternum littorale (Callichthyidae, Rineloricaria cadeae (Loricariidae, Eigenmannia trilineata (Sternopygidae, Odontesthes mirinensis and O. perugiae (Atherinopsidae. Apparently, the black catfish T. lucenai invaded the system in the last decade and became one of the dominant species in the pelagic waters. Although differences in gears hindered direct comparisons, differences in species composition and dominance patterns between shallow margins and pelagic waters of lakes seem to occur in the lakes. A more diverse assemblage dominated by small fishes ( 15 cm seemed to dominate in pelagic waters.

Parasitic fauna of eight species of ornamental freshwater fish species from the middle Negro River in the Brazilian Amazon Region Fauna parasitária de oito espécies de peixes ornamentais de água doce do médio Rio Negro na Amazônia brasileira

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Marcos Tavares-Dias

2010-06-01

Full Text Available Twenty-seven specimens of cardinal tetra Paracheirodon axelrodi, 33 rosy tetra Hyphessobrycon copelandi (Characidae, 28 marbled hatchetfish Carnegiella strigata, 26 blackwing hatchetfish Carnegiella martae (Gasteropelecidae, 27 bodó Ancistrus hoplogenys (Loricariidae, 31 brown pencilfish Nannostomus eques, 38 oneline pencilfish Nannostomus unifasciatus (Lebiasinidae and 13 angelfish Pterophyllum scalare (Cichlidae were collected from the middle Negro River, State of Amazonas, Brazil, for parasitological studies. Out of the total of 223 fish examined, 143 (64.1% were parasitized by at least one parasite species. The highest prevalence rate was for Monogenea (36.7%, followed by Ichthyophthirius multifiliis (Ciliophora (20.6%, Trichodina spp. (Ciliophora (4.0%, Piscinoodinium pillulare (Dinoflagellida (1.3%, Tetrahymena sp. (Ciliophora (0.89%, and Procamallanus sp. (Nematoda (0.4%. All eight fish species had Monogenea (Gyrodactylidae and Dactylogyridae in the gills, but the highest prevalence occurred in P. scalare and the lowest in P. axelrodi and C. strigata. However, the highest mean intensity of Monogenea was found in P. scalare and A. hoplogenys. The protozoan I. multifiliis occurred in the six ornamental fish species examined, but C. strigata and C. martae had higher prevalence and mean intensity. Trichodina spp. were found only in the gills of C. strigata, C. martae and N. eques, and with higher mean intensity in C. strigata. On the other hand, the protozoan P. pilullare was found only in the gills of C. martae. This is the first report of Tetrahymena sp. in Brazil, and it occurred in the gills of C. strigata.Para estudos parasitológicos, 27 espécimes de cardinal Paracheirodon axelrodi, 33 rosa-céu Hyphessobrycon copelandi (Characidae, 28 peixes borboleta Carnegiella strigata e 26 Carnegiella martae (Gasteropelecidae, 27 bodó ou cascudo Ancistrus hoplogenys (Loricariidae, 31 peixes-lápis Nannostomus eques e 38 Nannostomus unifasciatus

Morphological and behavioral development of the piracanjuba larvae Desenvolvimento morfológico e comportamental de larvas de piracanjuba

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Cláudia Maria Reis Raposo Maciel

2010-05-01

Full Text Available The objective of this work was to study the morphologic development and the swimming and feeding behaviors of piracanjuba larvae, Brycon orbignyanus Valenciennes (1849 (Characiformes, Characidae, Bryconinae, during the period from zero to 172 hours after hatching (standard length = 3.62 - 11.94 mm. The morphological analyses were accomplished by using a trinocular stereo microscope, while the behavioral analyses were performed through periodic observations. In 28 hours after hatching, the larvae (standard length = 6.25 ± 0.13 mm showed the following structural and behavioral characteristics that made them become active predators able to overcome a larval critical phase, the beginning of exogenous feeding: presence of pigmented eyes, terminal and wide mouth, developed oral dentition, developing digestive tube, yolk sac reduction, fins and swim bladder formation, horizontal swimming, cannibalism, and predation. Intense cannibalism among larvae was verified from 26 to 72 hours. At the end of the metamorphosis - 172 hours after hatching - the larvae measuring 11.94 + 0.80 mm in standard length presented a flexed notochord, caudal fin bifurcation, dorsal and anal fin formation, synchronized movements, and formation of shoals, characteristics that together allow enhanced perception and locomotio in exploration of the environment, determining the best moment for transfering to the fishponds. New studies can contribute to commercial fish farming by improving feeding management, performance, survival, and productivity of this species.Objetivou-se estudar o desenvolvimento morfológico e os comportamentos natatório e alimentar de larvas de piracanjuba, Brycon orbignyanus Valenciennes (1849 (Characiformes, Characidae, Bryconinae no período de 0 a 172 horas após a eclosão (comprimento-padrão = 3,62 - 11,94 mm. As análises morfológicas foram realizadas com auxílio de um microscópio estereoscópico trinocular e as comportamentais, por meio de

BIOCHEMICAL PARAMETERS FOR Piaractus mesopotamicus, Colossoma macropomum (Characidae AND HYBRID TAMBACU (P. mesopotamicus X C. macropomum

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Marcos Tavares-Dias

2010-06-01

Full Text Available A study for investigating the values of plasma glucose,serum total protein and serum ions (calcium, potassium, magnesium,sodium and chloride was carried out in young Colossomomamacropomum Cuvier, 1818, Piaractus mesopotamicus Holmberg,1887 and the hybrid tambacu (P. mesopotamicus x C. macropomum,kept in intensive system. Glucose concentrations were higher intambacu than in P. mesopotamicus and C. macropomum. Totalprotein levels were higher in P. mesopotamicus than both C.macropomum and tambacu. C. macropomum presented higherconcentrations of sodium and chloride, while P. mesopotamicushad higher concentrations of potassium and magnesium.However, levels of calcium were similar for the species studied.The hybrid tambacu showed the smallest levels of total protein,and intermediate levels of sodium, potassium, magnesium andchloride, compared to both P. mesopotamicus and C. macropomum.Baseline values for healthy fish in aquaculture were established,and they may be used for further comparisons in studies with wildpopulations of P. mesopotamicus and C. macropomum.

Toxicity and genotoxicity in Astyanax bimaculatus (Characidae induced by microcystins from a bloom of Microcystis spp

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Ricardo Rocha Pavan da Silva

2010-01-01

Full Text Available Studies of genotoxicity in fish caused by cyanobacterial microcystins can be useful both in determining the sensitivity of native species, as well as comparing exposure routes. The genotoxicity caused by the microcystins LR and LA from a bloom collected in a eutrophic lake, was revealed in the fish Astyanax bimaculatus, a native species from South America. LC50 (72 h was determined as 242.81 µg L-1 and LD50 (72 h as 49.19 µg kg-1 bw. There was a significant increase of DNA damage in peripheral erythrocytes, following intraperitoneal injection (ip with tested concentrations of 24.58 µg kg-1 bw and 36.88 µg kg-1 bw, as well as through body exposure to a concentration of 103.72 µg L-1. Micronucleus (MN induction was observed after ip injections of 24.58 µg kg-1 bw and 36.88 µg kg-1 bw for 72 h, as well as following body exposure for 72 at 103.72 µg L-1. Thus, both exposure routes resulted in MN induction and DNA damage. Apoptosis-necrosis testing was carried out only by ip injection with concentrations of 24.58 µg -1 bw and 36.88 µg kg-1 bw. Exposure to microcystins at lower concentrations induced more apoptosis than necrosis in peripheral erythrocytes, whereas exposure at higher concentrations gave rise to both conditions. Thus, Astyanax bimaculatus can be considered as a species sensitive to the genotoxic effects caused by microcystins.

Environmental pollution affects molecular and biochemical responses during gonadal maturation of Astyanax fasciatus (Teleostei: Characiformes: Characidae).

Science.gov (United States)

Tolussi, Carlos E; Gomes, Aline D Olio; Kumar, Anupama; Ribeiro, Cristiele S; Nostro, Fabiana L Lo; Bain, Peter A; de Souza, Gabriela B; Cuña, Rodrigo Da; Honji, Renato M; Moreira, Renata G

2018-01-01

Endocrine disrupting compounds (EDCs) have the potential to alter fish reproduction at various levels of organization. The aim of this study was to assess the impact of a natural environment with heavily anthropogenic influence on the physiological processes involved in reproduction in the freshwater fish lambari (Astyanax fasciatus) using different biomarkers. Adult males and females were collected in different seasons from two distinct sites in the same watershed: Ponte Nova Reservoir (PN) considered a pristine or small anthropogenic influence reference point; and Billings Reservoir (Bil), subjected to a large anthropogenic impact. Biological indices, such as hepatosomatic index and gonadosomatic index (GSI), gonadal histomorphology, fecundity, and biomarkers such as plasma levels of estradiol (E2) as well as hepatic gene expression of its alfa nuclear receptor (ERα), were analyzed. Hepatic vitellogenin (VTG) gene expression was evaluated in both sexes, as an indicator of xenoestrogen exposure. Females collected at PN presented a typical annual variation reflected in GSI, whereas for those sampled at Bil the index did not change through the seasons. The higher concentration of E2 in males collected at Bil during spring/2013, together with the detection of VTG gene expression, suggest the presence of EDCs in the water. These EDCs may have also influenced fecundity of females from Bil, which was higher during winter and spring/2013. Gene expression of ERα and ovarian morphology did not differ between fish from both sites. Water conditions from Bil reservoir impacted by anthropic activity clearly interfered mainly with biomarkers of biological effect such as plasma E2 levels and absolute and relative fecundity, but also altered biomarkers of exposure as VTG gene expression. These facts support the notion that waterborne EDCs are capable of causing estrogenic activity in A. fasciatus. Copyright © 2017 Elsevier Inc. All rights reserved.

Reproductive biology of Bryconamericus stramineus Eigenmann, 1908 (Ostariophysi: Characidae from the Rio Ibicuí, RS, Brazil

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Vinicius Renner Lampert

2007-11-01

Full Text Available Reproduction of Bryconamericus stramineus was described based on the analysis of 208 females and 166 males collected monthly in the Rio Ibicuí, from April 2001 through March 2002. Reproduction occurred between September and December, with a lower peak in February. The mean absolute fecundity was 371.3 (± 244.6 oocytes and the mean relative fecundity was 0.35 (± 0.08 oocytes/mg of total weight and the fish was a multiple spawner. A weak correlation between GSI of males and day length was observed. Other parameters (stomach repletion and hepatosomatic index, rainfall and temperature did not show any correlation with GSI. However, some of these factors might act as "starters" of gonadal maturation. The presence and frequency of fin ray hooks on the males was compared with the gonadal maturation stages, months and standard length classes. Well-developed hooks were found mainly in the mature males during the reproductive period and in the largest individuals.A reprodução de Bryconamericus stramineus é descrita baseada na análise de 208 fêmeas e 166 machos coletados mensalmente no rio Ibicuí, RS, de abril/2001 a março/2002. A reprodução ocorreu entre setembro e dezembro, com um pico menor em fevereiro. A fecundidade absoluta média é de 371.3 (± 244.6 ovócitos e a fecundidade relativa média é de 0.35 (± 0.08 ovócitos/mg de peso total e a espécie tem desova parcelada. Foi observada uma fraca correlação entre IGS de machos e fotoperíodo; os índices de repleção estomacal e hepatossomático, a pluviosidade e temperatura não mostraram nenhuma correlação. Porém, sugerimos que alguns destes fatores possam agir como "desencadeadores" da maturação gonadal. A presença e freqüência de ganchos nas nadadeiras de machos foi comparada com as fases de maturação gonadal, meses e classes de comprimento padrão. Ganchos bem-desenvolvidos foram encontrados principalmente em machos maduros, durante o período reprodutivo e nos indivíduos maiores.

New species of Moenkhausia Eigenmann, 1903 (Characiformes: Characidae with comments on the Moenkhausia oligolepis species complex

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Ricardo C. Benine

Full Text Available A new species of Moenkhausia is described from tributaries of the rio Paraguay, Brazil. The new species is diagnosed from congeners by characters related to body coloration, the number of lateral line scales, the degree of poring of the lateral line, and number of scales rows above and below the lateral line. Molecular analyses using partial sequences of the mitochondrial gene Cytochrome Oxidase I from specimens of the new species and specimens belonging to morphologically similar species demonstrated that the new species is easily differentiated by their high genetic distance and by their position in the phylogenetic hypothesis obtained through the Maximum Parsimony methodology. The analyses of three samples of M. oligolepis also revealed that they have high genetic distances and belong to different monophyletic groups suggesting that this species corresponds to a species complex rather than a single species.

Morphological variation among populations of Hemigrammus coeruleus (Characiformes: Characidae in a Negro River tributary, Brazilian Amazon

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Henrique Lazzarotto

2017-03-01

Full Text Available ABSTRACT We explored patterns of phenotypic variation in Hemigrammus coeruleus from the Unini River basin, a blackwater river in the Brazilian Amazon. Geometric morphometrics was used to evaluate variation in body shape among populations from four tributaries (UN2-UN5. We found no evidence for sexual dimorphism in body size and shape. However, morphological differences among populations were detected as the analyses recovered significant groups corresponding to each sub-basin, with some overlap among them. The populations from UN2, UN3 and UN5 had more elongate bodies than fish from UN4. The most morphologically divergent population belonged to UN4, the tributary with the most divergent environmental conditions and the only one with seasonally-muddy waters. The morphological variation found among these populations is likely due to phenotypic plasticity or local adaptation, arising as a product of divergent ecological selection pressures among sub-basins. This work constitutes one of the first to employ a population-level geometric morphometric approach to assess phenotypic variation in Amazonian fishes. This method was able to distinguish subtle differences in body morphology, and its use with additional species can bring novel perspectives on the evaluation of general patterns of phenotypic differentiation in the Amazon.

Extensive polymorphism and chromosomal characteristics of ribosomal DNA in the characid fish Triportheus venezuelensis (Characiformes, Characidae

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Mauro Nirchio

2007-01-01

Full Text Available The karyotype and chromosomal characteristics of the characid fish Triportheus venezuelensis were investigated using differential staining techniques (C-banding, Ag-NOR staining and fluorescent in situ hybridization (FISH with an 18S rDNA probe. The diploid chromosome number (2n = 52, karyotype composition and sex chromosome determination system of the ZZ/ZW type were the same as previously described in other species of the genus Triportheus. However, extensive variation regarding nucleolus organizer regions (NOR different from other species was observed. 18S rDNA sequences were distributed on nine chromosome pairs, but the number of chromosomes with Ag-NORs was usually lower, reaching a maximum of four chromosomes. When sequential staining experiments were performed, it was demonstrated that: 1. active NORs usually corresponded to segments with 18S rDNA genes identified in FISH experiments; 2. several 18S rDNA sequences were not silver-stained, suggesting that they do not correspond to active NORs; and 3. some chromosomes with silver-stained regions did not display any 18S rDNA signals. These findings characterize an extensive polymorphism associated with the NOR-bearing chromosomes of T. venezuelensis and emphasize the importance of combining traditional and molecular techniques in chromosome studies.

A new species of Hyphessobrycon (Characiformes, Characidae from the upper Guaviare River, Orinoco River Basin, Colombia

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Carlos A. García-Alzate

2017-04-01

Full Text Available Hyphessobrycon klausanni sp. n. is described from small drainages of the upper Guaviare River (Orinoco River Basin in Colombia. It differs from all congeners by having a wide, conspicuous, dark lateral stripe extending from the anterior margin of the eye across the body and continued through the middle caudal-fin rays, and that covers (vertically three or four horizontal scale rows. It also differs by having an orange-yellow stripe extending from the anterosuperior margin of the eye to the caudal peduncle above the lateral line in life. It differs from all other species of Hyphessobrycon that have a similar dark lateral stripe: H. cyanotaenia, H. loretoensis, H. melanostichos, H. nigricinctus, H. herbertaxelrodi, H. eschwartzae, H. montogoi, H. psittacus, H. metae, H. margitae, H. vanzolinii, and H. peruvianus in having only three or four pored scales in the lateral line, 21 to 24 lateral scales and six teeth in the inner premaxillary row. Hyphessobrycon klausanni differs from H. loretoensis in having seven to eight maxillary teeth (vs. three to four and in having a longer caudal peduncle (12.4–17.0% SL vs. 4.6–8.0% SL. Additionally Hyphessobrycon klausanni can be distinguished from the other species of Hyphessobrycon with a dark lateral stripe from the Orinoco River Basin (H. metae and H. acaciae in having two teeth in the outer premaxillary row (vs. three to four and 10 branched pectoral–fin rays (vs. 11 to 12. It further differs from H. metae by the length of the snout (17.6–22.8% HL vs. 9.9–15.2% HL and by the length of the caudal peduncle (12.4–17.0% SL vs. 7.3–11.8% SL.

CARACTERIZACION DE LA PRODUCTIVIDAD PESQUERA DESARROLLADA EN LA COCHA JACINTO, RESERVA NACIONAL PACAYA SAMIRIA

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Javier del Águila Chávez

2011-12-01

Full Text Available El presente estudio describe las características de la productividad pesquera por un periodo de cuatro años  en la “cocha Jacinto”. La “cocha Jacinto” está ubicada en la Reserva Nacional Pacaya Samiria (RNPS (coordenadas UTM E 0623314 y N 9495909, Loreto, Perú. Los datos fueron recolectados a partir de fichas de registro de pesca llenadas por el propio pescador. La productividad pesquera se estimó por el número de individuos con mayor captura, captura por unidad de esfuerzo (CPUE  y biomasa bruta según consumo (BBC. Los datos fueron digitados y analizados utilizando el programa Microsoft Excel v. 2000.Durante el periodo 2006 – 2009: a Los individuos con mayor captura fueron la “Carachama” (Fam. Loricaridae, “sardina” (Fam. Characidae, “Fasaco” (Fam. Erythrinidae y “Shuyo” (Fam. Erythrinidae; b con respecto a la CPUE: 0.16 kg/hora,  0.15 kg/hora, 0.38 kg/hora y 0.65 kg/hora; y c la BBC osciló entre 56.85 kg, 45.81 kg, 202.04 kg y  81.63 kg, según respectivo año. Las diferencias de la CPUE indican un probable incremento de la producción pesquera. Sin embargo se necesitan mayores estudios para evaluar las dinámicas de la producción pesquera y evaluar factores sociales.  Limitación a considerar es la calidad de los datos recolectados

Discovering Hidden Diversity of Characins (Teleostei: Characiformes) in Ecuador's Yasuní National Park.

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Escobar-Camacho, Daniel; Barriga, Ramiro; Ron, Santiago R

2015-01-01

Management and conservation of biodiversity requires adequate species inventories. The Yasuní National Park is one of the most diverse regions on Earth and recent studies of terrestrial vertebrates, based on genetic evidence, have shown high levels of cryptic and undescribed diversity. Few genetic studies have been carried out in freshwater fishes from western Amazonia. Thus, in contrast with terrestrial vertebrates, their content of cryptic diversity remains unknown. In this study, we carried out genetic and morphological analyses on characin fishes at Yasuní National Park, in eastern Ecuador. Our goal was to identify cryptic diversity among one of the most speciose fish families in the Amazon region. This is the first time that genetic evidence has been used to assess the species content of the Napo Basin, one of the richest regions in vertebrate diversity. Phylogenetic analyses of partial mitochondrial 16S ribosomal RNA gene (∼600 pb) DNA sequences from 232 specimens of the family Characidae and its closest groups revealed eight candidate new species among 33 species sampled, representing a 24% increase in species number. Analyses of external morphology allowed us to confirm the species status of six of the candidate species. Our results show high levels of cryptic diversity in Amazonian characins. If this group is representative of other Amazonian fish, our results would imply that the species richness of the Amazonian ichthyofauna is highly underestimated. Molecular methods are a necessary tool to obtain more realistic inventories of Neotropical freshwater fishes.

CARACTERIZACION DE LA PRODUCTIVIDAD PESQUERA DESARROLLADA EN LA COCHA JACINTO, RESERVA NACIONAL PACAYA SAMIRIA

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Javier del Águila Chávez

2011-12-01

Full Text Available El presente estudio describe las características de la productividad pesquera por un periodo de cuatro años  en la “cocha Jacinto”. La “cocha Jacinto” está ubicada en la Reserva Nacional Pacaya Samiria (RNPS (coordenadas UTM E 0623314 y N 9495909, Loreto, Perú. Los datos fueron recolectados a partir de fichas de registro de pesca llenadas por el propio pescador. La productividad pesquera se estimó por el número de individuos con mayor captura, captura por unidad de esfuerzo (CPUE  y biomasa bruta según consumo (BBC. Los datos fueron digitados y analizados utilizando el programa Microsoft Excel v. 2000. Durante el periodo 2006 – 2009: a Los individuos con mayor captura fueron la “Carachama” (Fam. Loricaridae, “sardina” (Fam. Characidae, “Fasaco” (Fam. Erythrinidae y “Shuyo” (Fam. Erythrinidae; b con respecto a la CPUE: 0.16 kg/hora,  0.15 kg/hora, 0.38 kg/hora y 0.65 kg/hora; y c la BBC osciló entre 56.85 kg, 45.81 kg, 202.04 kg y  81.63 kg, según respectivo año. Las diferencias de la CPUE indican un probable incremento de la producción pesquera. Sin embargo se necesitan mayores estudios para evaluar las dinámicas de la producción pesquera y evaluar factores sociales.  Limitación a considerar es la calidad de los datos recolectados.

Composición de especies y diversidad de peces en tres cuerpos de agua en la cuenca alta del río Itaya

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Javier del Águila Chávez

2013-06-01

Full Text Available En el presente trabajo se describe sobre la diversidad en tres cuerpos de agua de la cuenca alta del río Itaya, concesión de conservación de la universidad científica del Perú, en una evaluación rápida en los meses de junio y julio del 2012. Se colectaron datos y muestras de peces en Lamas cocha (LC, cocha Anguilla (CA y Tipishca Luz de Oriente (TLO. Los peces fueron colectados utilizando una batería de redes de diferentes medidas 1.5, 2, 2.5, 3, 3.5 y 4 pulgadas de de abertura de malla. Se reportan 17 familias taxonómicas, de las cuales 9 familias pertenecen al orden Characiformes (53%, 3 familias pertenecen al orden de los Siluriformes (17%, 2 familias pertenecen al orden de los Gymnotiformes (12% y al orden Perciformes (12% y una familia pertenece al orden Beloniformes (6%. La predominancia de las familias taxonómicas en los tres ambientes fueron Characidae, Curimatidae, Acestrorhynchidae (Characiformes y Cichlidae (Perciformes. Sin embargo, la ocurrencia de exclusividad de una determinada familia fue observada en los tres cuerpos de aguas; tenemos de esta forma la familia Hemiodontidae solo tienen ocurrencia en Lamas cocha, la ocurrencia de la familia Prochilodontidae (Characiformes y Callichthyidae (Siluriformes en Cocha Anguillal y finalmente la ocurrencia de las familias Pimelodidae (Siluriformes, Sciaenidae (Perciformes y Belonidae (Beloniformes en la Tipishca Luz de Oriente.

Composición de especies y diversidad de peces en tres cuerpos de agua en la cuenca alta del río Itaya

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Javier del Águila Chávez

2013-06-01

Full Text Available En el presente trabajo se describe sobre la diversidad en tres cuerpos de agua de la cuenca alta del río Itaya, concesión de conservación de la universidad científica del Perú, en una evaluación  rápida en los meses de junio y julio del 2012. Se colectaron datos y muestras de peces en Lamas cocha (LC, cocha Anguilla (CA y Tipishca Luz de Oriente (TLO. Los peces fueron colectados utilizando una batería de redes de diferentes medidas 1.5, 2, 2.5, 3, 3.5 y 4 pulgadas de de abertura de malla. Se reportan 17 familias taxonómicas, de las cuales 9 familias pertenecen al orden Characiformes (53%, 3 familias pertenecen al orden de los Siluriformes (17%, 2 familias pertenecen al orden de los Gymnotiformes (12%  y al orden Perciformes (12% y una familia pertenece al orden Beloniformes (6%. La predominancia de las familias taxonómicas en los tres ambientes fueron Characidae, Curimatidae, Acestrorhynchidae (Characiformes y Cichlidae (Perciformes. Sin embargo, la ocurrencia de exclusividad de una determinada familia fue observada en los tres cuerpos de aguas; tenemos de esta forma la familia Hemiodontidae solo tienen ocurrencia en Lamas cocha, la ocurrencia de la familia Prochilodontidae (Characiformes y Callichthyidae (Siluriformes en Cocha Anguillal y finalmente la ocurrencia de las familias Pimelodidae (Siluriformes, Sciaenidae (Perciformes y Belonidae (Beloniformes en la Tipishca Luz de Oriente.

O lambari Astyanax altiparanae (Characidae pode ser um dispersor de sementes? - DOI: 10.4025/actascibiolsci.v25i2.2045 Can lambari, Astyanax altiparanae (Characidae, be a seed disperser? - DOI: 10.4025/actascibiolsci.v25i2.2045

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Leandro Muller Gomiero

2003-04-01

Full Text Available Este trabalho caracterizou a alimentação natural de Astyanax altiparanae na sub-bacia do rio Corumbataí e bacia do rio Jacaré-pepira, com enfoque principal na ingestão de sementes de Croton urucurana. Os itens alimentares de Astyanax altiparanae, em ordem decrescente de Grau de Preferência Alimentar (GPA, foram: insetos alóctones, restos de insetos, material vegetal alóctone, sementes de Croton urucurana, insetos autóctones, sedimentos, material vegetal autóctone, escamas, ovócitos e aracnídeos. Sementes de Croton urucurana ocorreram no verão, época de cheia dos rios. Sugere-se que Astyanax altiparanae seja um dispersor secundário das sementes de Croton urucurana, sendo que a intensidade e a efetividade dessa dispersão devem, ainda, ser investigadasThis work characterized the feeding of Astyanax altiparanae in the sub-basin of Corumbataí river and in the basin of Jacaré-pepira river with a focus on the ingestion of Croton urucurana seeds. The food items of Astyanax altiparanae were, in decreasing APD (Alimentary Preference Degree order: allochthonous insects, allochthonous plant material, Croton urucurana seeds, autochthonous insects, sediments, autochthonous plant material, scales, oocytes and arachnidans. Croton urucurana seeds occurred during the summer, in the flood period. Lambari, Astyanax altiparanae, could be a secondary disperser of Croton urucurana seeds, however, the intensity and effectiveness of this dispersion may be still investigated

Sondeo ecológico rápido de las comunidades de peces tropicales en un área de explotación minera en Costa Rica

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Mario Espinoza Mendiola

2008-12-01

Full Text Available El impacto de las minerías de oro ha generado una gran preocupación por el deterioro de los hábitats acuáticos y la fragmentación de los sistemas naturales. Las perturbaciones antropogénicas sobre la estructura y heterogeneidad del sistema pueden influir en la estabilidad de las comunidades acuáticas. Sondeos ecológicos rápidos (1996, 2002, 2007 fueron empleados para determinar la estructura, composición y distribución de las comunidades de peces tropicales en varios ríos y quebradas del área de una minería de oro en el Cerro Crucitas, Costa Rica. Además, la composición de especies y abundancia relativa se relacionó con la estructura del hábitat. Se registró un total de 35 especies, de las cuales la sardina Astyanax aeneus (Characidae y la olomina Alfaro cultratus (Poeciliidae fueron las especies más abundantes (71%. La mayor riqueza de especies se observó en el Caño Crucitas (s = 19 y la quebrada Minas (s = 18. Se encontró una gran variación en la estructura y composición de las comunidades de peces, principalmente, en el río Infiernillo y Minas (λ = 0.0, F132, 66 = 2.24, p Rapid ecological assessment of tropical fish communities in a gold mine area of Costa Rica. Gold mining impacts have generated a great concern regarding aquatic systems and habitat fragmentation. Anthropogenic disturbances on the structure and heterogeneity of a system can have an important effect on aquatic community stability. Ecological rapid assessments (1996, 2002, and 2007 were employed to determine the structure, composition and distribution of tropical fish communities in several rivers and smaller creeks from a gold mining area in Cerro Crucitas, Costa Rica. In addition, species composition and relative abundance were related with habitat structure. A total of 35 species were registered, among which sardine Astyanax aeneus (Characidae and livebearer Alfaro cultratus (Poeciliidae were the most abundant fish (71%. The highest species

Comparison of spermiogenesis in the externally fertilizing Hemigrammus erythrozonus and the inseminating Corynopoma riisei (Teleostei: Characiformes: Characidae

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Anna Pecio

Full Text Available Spermiogenesis and sperm ultrastructure were analyzed in two species of characids with different modes of fertilization: externally fertilizing Hemigrammus erythrozonus and inseminating Corynopoma riisei. Spermiogenesis in H. erythrozonus is characterized by lateral development of the flagellum, nuclear rotation, formation of a shallow nuclear fossa, condensation of the chromatin by elimination of the electron-lucent area from the peripheral region of the nucleus, and renewal of the nuclear membrane. Multilammelated membrane and multivesicular bodies were also observed during elimination of the excess cytoplasm. The spermatozoon exhibits characters typical of "aquasperm," i.e. a spherical head containing a spherical nucleus with highly condensed chromatin, several small mitochondria located at the base of the nucleus within a cytoplasmic collar that extends into a long cytoplasmic sleeve surrounding the anterior part of the single flagellum, which is contained within a cytoplasmic canal. The flagellum lacks fins. The proximal and distal centrioles are nearly parallel to one another, with the anterior tips of both located within shallow nuclear fossae. Spermiogenesis in C. riisei is characterized by nuclear elongation alongside the forming flagellum, formation of an elongate cytoplasmic canal, displacement and elongation of the mitochondria, and uniform condensation of chromatin throughout the nucleus through enlargement of the diameter of the chromatin granules. The spermatozoon has an elongate nucleus with two elongate mitochondria localized to one side. Mitochondria are also located posterior to the nucleus forming a mitochondrial region. The single flagellum, which lacks fins, is lateral to the nucleus and initially contained within the greatly elongate cytoplasmic canal before exiting the canal at its posterior terminus. The spermatozoon of C. riisei exhibits several characters typical of "introsperm," such as an elongate nucleus and midpiece (mitochondrial region. The nuclear chromatin in the spermatozoon remains "flocculent" and is never as condensed as that seen in many characid sperm. Differences in spermiogenesis between externally fertilizing and inseminating characids are discussed.

Comparative dietary analysis of two populations of Mimagoniates rheocharis (Characidae: Glandulocaudinae from two streams of Southern Brazil

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Ana Paula S. Dufech

Full Text Available The diet of two populations of Mimagoniates rheocharis, from two freshwater streams of the rio Tramandaí, northeastern Rio Grande do Sul, Brazil, are described and compared. The specimens were collected monthly from January 1998 to March 1999, with dip nets and seine nets and preserved in 10% formalin. In laboratory, the standard length of each specimen was measured. The stomachs were removed and dissected for identification of the alimentary items. The data were analyzed using the frequency of occurrence, percent composition and index of alimentary importance methods, being the last two compared among different classes of standard length. Three methods of analysis showed the highest values for allochthonous insects, regardless the locality of collection or body size of the specimens.

Population structure, fluctuating asymmetry and genetic variability in an endemic and highly isolated Astyanax fish population (Characidae

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Maria Claudia Gross

2004-01-01

Full Text Available Morphological and chromosomal markers were used to infer the structure and genetic variability of a population of fish of the genus Astyanax, geographically isolated at sinkhole 2 of Vila Velha State Park, Paraná, Brazil. Two morphotypes types were observed, the standard phenotype I and phenotype II which showed an anatomical alteration probably due to an inbreeding process. Fluctuating asymmetry (FA analysis of different characters showed low levels of morphological variation among the population from sinkhole 2 and in another population from the Tibagi river (Paraná, Brazil. The Astyanax karyotype was characterized in terms of chromosomal morphology, constitutive heterochromatin and nucleolar organizer regions. Males and females presented similar karyotypes (2n=48, 6M+18SM+14ST+10A with no evidence of a sex chromosome system. One female from sinkhole 2 was a natural triploid with 2n=3x=72 chromosomes (9M+27SM+21ST+15A. The data are discussed regarding the maintenance of population structure and their evolutionary importance, our data suggesting that Astyanax from the Vila Velha State Park sinkhole 2 is a recently isolated population.

Cultivo primário de células hepáticas de Metynnis roosevelti (Pisces, Teleostei, Characidae

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Ligia Maria Salvo

2000-01-01

Full Text Available A fim de obter culturas celulares e monocamada de células hepáticas do peixe subtropical Metynnis roosevelti, foram comparadas três metodologias: dissociação celular enzimática com tripsina versene 0,25%; utilização do soro fetal bovino; e soro homólogo, obtido por meio da punção da veia caudal, de exemplares adultos da mesma espécie de peixe. O meio de cultura utilizado foi F10-199 acrescido de L-glutamina 2 mM, insulina 10 µg/mL, fibronectina 50 µg/mL; e antibióticos. A dissociação celular enzimática apresentou maior eficiência na adesão e confluência da monocamada celular em comparação a outras metodologias utilizadas.

Morphology of the urogenital papilla and its component ducts in Astyanax altiparanae Garutti & Britski, 2000 (Characiformes: Characidae

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Diógenes Henrique de Siqueira-Silva

Full Text Available The histological description of the urogenital papilla is an important tool to comprehension of the reproductive mechanisms in fish, as well as a pre-requisite to germ cell transplantation in adult fish, besides to be a good biological indicator to environmental changes. Was performed the histological description of the urogenital papilla and its component ducts in the tetra Astyanax altiparanae. The genital and urinay ducts pass separately throughout most part of its extension, joining in a single duct before opening. In males this opening is asymmetric and seems to have double origin, being completely surrounded by striated muscle fibers, while in females it is symmetric and the muscle fibers does not surround it totally. Spermatic duct and oviduct undergo changes throughout their extension, mainly in the morphology of the surrounding epithelium. In the spermatic duct, squamous epithelial cells change to columnar and cuboid with possible secretory activity, close to testes. In the oviduct, anteriorly epithelial cells are also squamous, however, close to ovary there are lamellae composed by a pseudostratified epithelium with columnar and cuboid cells. The urinary duct is highly similar for both sexes presenting globoid cells, which description is known in mammals, however, rare in fish.

Oligosarcus jacuiensis (Characiformes: Characidae, a new species from the Uruguay and Jacuí River basins, southern Brazil

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Naércio Aquino Menezes

Full Text Available The new species herein described, collected in the Jacuí and Uruguay River basins, Rio Grande do Sul, Brazil, can be distinguished from the already known species of the genus, but Oligosarcus jenynsii, O. perdido, O. acutirostris, O. solitarius and O. hepsetus, by the number of perforated lateral line scales. It shares with the first two species the absence of a premaxillary foramen, present in the last three species and differs from O. jenynsii by having a smaller orbital diameter and the tip of the pectoral fin failing to reach the pelvic-fin origin, and from O. perdido by the presence of more horizontal scale rows around the caudal peduncle.

Reproductive traits and population structure of Astyanax aeneus (Characiformes: Characidae from a subtropical river in Mexico Rasgos reproductivos y estructura de la población de Astyanax aeneus (Characiformes: Characidae de un río subtropical en México

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Patricia Trujillo-Jiménez

2013-06-01

Full Text Available Champotón River is an unknown area within the Mesoamerican hotspot in Southestern México. Reproductive traits and population structure of Astyanax aeneus were analyzed along an environmental gradient of the upper, middle and lower sections of the river, where diverse environmental factors were recorded. For this, nets were cast for 1h at each site and A. aeneus were collected from all sections with sweep nets (5 and 10m long by 5m deep, 0.03m mesh size and a casting net (0.05m mesh size. At each study site and campaign, a total of 80 specimens (in average were collected and were fixed in 10% formaldehyde for further analysis. Population structure by size was analyzed for each study site, based on the relative frequencies by standard length classes. The length-weight relationship was determined, and the identification of gonadal developmental stages, reproductive period, size at first sexual maturity, relative fecundity, sex ratio and somatic indexes (gonadosomatic, hepatosomatic and Fulton’s condition factor were also assessed. Seven size classes were found in the upper and middle sections, and nine downstream, with seasonal and spatial pattern in size-class frequency distribution. Size at first maturity was 45.7mm for females and 40.8mm for males. The maximum relative fecundity was recorded at the downstream site and was positively correlated with body weight and standard length. Sex ratio (1.8:1 males: females differed significantly from expected values (1:1. Gonadosomatic index scores indicated that the reproductive period of this species in the Champotón River was from April to July, during the warm and wet season. Hepatosomatic index was negatively correlated with the Gonadosomatic index, evidencing transfer of energy from the liver towards gamete production. This strategy enabled A. aeneus to maintain robustness during the study period with tiny changes in condition factor. A. aeneus in the Champotón River, as opposed to South American river congeneric species of similar size, shows early sexual maturity, a short reproductive period with high gonadosomatic index values, and high fecundity, a trade-off for the short reproductive period. Spatio-temporal segregation was evident: breeders congregate down- stream, while juveniles prefer the upper reaches. This pattern allows A. aenus to be successful in a river with high frequency of hurricanes.El Río Champotón es un área de desconocimiento científico dentro del hotspot de Mesoamérica en el sureste de México. Las características reproductivas y la estructura de la población de Astyanax aeneus fueron analizadas a lo largo de un gradiente ambiental en la porción dulceacuícola del río. Se estudiaron tres sitios: en la parte alta del río San Juan Carpizo, en la porción media San Antonio del Río y río abajo en Ulumal, en cinco períodos entre 2007 y 2008. Se registraron diversos factores ambientales en cada sitio de estudio. Los ejemplares de A. aeneus se recolectaron con redes de arrastre de 5 y 10m de largo por 5m de profundidad (0.03m malla y atarraya (con luz de malla de 0.05m. Las redes fueron lanzadas durante 1 hora en cada sitio. En cada visita se recolectaron un promedio de 80 especímenes en cada sitio de estudio que se preservaron en formaldehído al 10% para su posterior análisis. Para cada sitio de estudio se analizó la estructura de la población por talla, con base en las frecuencias relativas de las clases de longitud estándar. Se determinó la relación peso-talla, se identificaron las etapas del desarrollo gonadal, la época reproductiva, el tamaño de primera madurez sexual, la fecundidad absoluta y relativa, la proporción de sexos y los índices somáticos (gonadosomático, hepatosomático y el factor de condición de Fulton. Se obtuvieron siete clases de talla en la parte alta y media del río y nueve río abajo, con un patrón de distribución estacional y espacial en las frecuencias de clase de tallas. La talla de primera madurez fue de 45.7mm en hembras y 40.8mm en machos. La máxima fecundidad absoluta se registró río abajo y se correlacionó positivamente con el peso corporal y la longitud estándar. La proporción de sexos (1.8:1 machos: hembras difiere significativamente de los valores esperados (1:1. Los resultados del índice gonadosomático (IGS indican que el período reproductivo en el Río Champotón es en julio, durante la temporada húmeda y cálida. El índice hepatosomático se correlacionó negativamente con el IGS, evidenciando la transferencia de energía desde el hígado hacia la producción de gametos. Esta estrategia permitió que A. aeneus mantuviera una condición robusta durante el periodo de estudio con pequeños cambios en el factor de condición. Nuestros resultados indican que A. aeneus en el río Champotón, a diferencia de otras especies del mismo género y de la misma talla en ríos de Sudamérica, presenta una maduración sexual precoz, una temporada reproductiva corta con elevados valores del IGS, y una elevada fecundidad, lo que compensa la temporada de reproducción corta. También se percibe una tendencia a la segregación espacial y temporal: los reproductores se congregan aguas abajo y los juveniles prefieren las partes más altas. Este patrón permite a A. aeneus tener éxito en un río con una alta frecuencia de huracanes.

Development of fingerlings of Piracanjuba (Brycon orbignyannus, Vallencienes (1849 (Teleostei: characidae in tanks fertilized with organic manures/ Desenvolvimento de juvenis de Piracanjuba (Brycon orbignyannus, Vallencienes (1849 (Teleostei: characidae em tanques experimentais fertilizados com adubação orgânica

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Carmino Hayashi

2005-06-01

Full Text Available The objective of this paper was to study the development of Piracanjuba (Brycon orbignyanus in tanks under differents organic fertilizers. The experiment, entirely randomized, was accomplished in 16 tanks of 1000 liters, fertilized with manures of bovine (BOV, pigs (SUI, chickens (FRG and others without fertilizer (SAO, using 15 fish/m3 with an initial average weight and length of 10,87+0,31 g e 9,78+0,07 cm. After 30 days, the experiment showed a uniform development of the fish and high survival rate in thestudied density. The treatments presented significant statistical differences (PO objetivo deste trabalho foi estudar o desenvolvimento de juvenis de Piracanjuba (Brycon orbignyanus, em tanques com adubações orgânicas. O experimento, inteiramente casualizado, foi realizado em 16 tanques de 1000 litros, adubados com estercos de bovinos (BOV, suínos (SUI, frangos de corte (FRG e outros sem adubação (SAO, utilizando 15 peixes/m3 com peso e comprimento médios iniciais de 10,87+0,31 g e 9,78+0,07 cm. Após 30 dias, o experimento mostrou um desenvolvimento uniforme dos peixes e alta taxa de sobrevivência na densidade estudada. Os tratamentos apresentaram diferenças estatisticamente significativas (p < 0,05 para ganho de peso e crescimento diário, com exceção dos tratamentos BOV e SUI quando comparados entre si. A temperatura e o oxigênio dissolvido foram os fatores abióticos que exerceram maior influência sobre a biota aquática, afetando o desenvolvimento dos peixes. Entre o fitoplâncton houve maior abundância de organismos nanoplanctônicos favorecendo o desenvolvimento do zooplâncton, destacando-se as clorófitas, com o gênero Scenedesmus, e as cianofíceas, com o gênero Microcystis, e entre o zooplâncton, a maior abundância foi de rotíferos dos gêneros Brachionus e Keratella, seguido por copépodas. O tratamento adubado com esterco de frangos possibilitou um maior desenvolvimento da comunidade planctônica, e melhores resultados quanto ao desenvolvimento dos peixes, demonstrando a importância do alimento natural na sua dieta.

Fauna parasitária de tambaqui Colossoma macropomum (Characidae cultivado em tanque-rede no estado do Amapá, Amazônia oriental Parasitic fauna of tambaqui Colossoma macropomum(Characidae farmed in cages in the State of Amapá, eastern Amazon

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Evandro Freitas Santos

2013-03-01

Full Text Available O objetivo principal deste trabalho foi estudar a parasitofauna e a relação hospedeiro- parasito em tambaqui Colossoma macropomum cultivados em tanques-rede no Rio Matapi, município de Santana, estado do Amapá, região da Amazônia oriental, Brasil. Foram examinados 60 tambaquis, dos quais 96,7% estavam parasitados por protozoários Ichthyophthirius multifiliis (Ciliophora e Piscinoodinium pillulare (Dinoflagellida, monogenoideas Mymarotheciun boegeri e Anacanthorus spathulatus (Dactylogyridae e sanguessugas Glossiiphonidae gen. sp. (Hirudinea. Os maiores níveis de parasitismo foram causados por protozoários I. multifiliis e P. pillulare e os menores por sanguessugas Glossiiphonidae gen. sp. Porém, os índices de infestação não tiveram efeitos na saúde dos peixes hospedeiros, uma vez que o fator de condição relativo (Kn não foi estatisticamente (pThe purpose of this paper was to evaluate the parasitic fauna and the host-parasite relationship in Colossoma macropomum farmed in cages of Matapi River, municipally of Santana, State of Amapá, in eastern Amazon, Brazil. Of 60 specimens of tambaqui examined, 96.7% were parasitized by protozoans Ichthyophthirius multifiliis (Ciliophora and Piscinoodinium pillulare (Dinoflagellida, monogenoideans Mymarotheciun boegeri and Anacanthorus spathulatus (Dactylogyridae, and leeches Glossiphoniidae gen. sp. (Hirudinea. The higher infestation levels were caused by protozoans I. multifiliis and P. pillulare, while the lower infestation levels were caused by leeches. No effects of parasitic infestation rates on fish health were observed. The relative condition factor (Kn was not correlated with the intensity of parasites found. This was the first record of I. multifiliis and P. pillulare in C. macropomum farmed in cages in the Brazilian Amazon.

Discovering Hidden Diversity of Characins (Teleostei: Characiformes) in Ecuador’s Yasuní National Park

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Escobar-Camacho, Daniel; Barriga, Ramiro; Ron, Santiago R.

2015-01-01

Background Management and conservation of biodiversity requires adequate species inventories. The Yasuní National Park is one of the most diverse regions on Earth and recent studies of terrestrial vertebrates, based on genetic evidence, have shown high levels of cryptic and undescribed diversity. Few genetic studies have been carried out in freshwater fishes from western Amazonia. Thus, in contrast with terrestrial vertebrates, their content of cryptic diversity remains unknown. In this study, we carried out genetic and morphological analyses on characin fishes at Yasuní National Park, in eastern Ecuador. Our goal was to identify cryptic diversity among one of the most speciose fish families in the Amazon region. This is the first time that genetic evidence has been used to assess the species content of the Napo Basin, one of the richest regions in vertebrate diversity. Results Phylogenetic analyses of partial mitochondrial 16S ribosomal RNA gene (∼600 pb) DNA sequences from 232 specimens of the family Characidae and its closest groups revealed eight candidate new species among 33 species sampled, representing a 24% increase in species number. Analyses of external morphology allowed us to confirm the species status of six of the candidate species. Conclusions Our results show high levels of cryptic diversity in Amazonian characins. If this group is representative of other Amazonian fish, our results would imply that the species richness of the Amazonian ichthyofauna is highly underestimated. Molecular methods are a necessary tool to obtain more realistic inventories of Neotropical freshwater fishes. PMID:26275041

HYPHESSOBRYCON NATAGAIMA (CHARACIFORMES: CHARACIDAE A NEW SPECIES FROM COLOMBIA, WITH A KEY TO THE MAGDALENA BASIN HYPHESSOBRYCON SPECIES

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CARLOS A. GARCÍA-ALZATE

2015-06-01

Full Text Available A new species, Hyphessobrycon natagaima, is described from the upper Magdalena River Basin in Colombia. It differs from all other species of Hyphessobrycon with a dark lateral stripe inhabiting the Magdalena River Basin: H. poecilioides, H. proteus and H. ocasoensis, by having eight to twelve pored lateral-line scales (vs. 14-26; four scales between the lateral line and the pelvic-fin insertions (vs. five or six; one tooth on the maxilla (vs. zero in H. poecilioides, and two to five in H. proteus; except H. ocasoensis, with one, a dark, interrupted, lateral stripe that is not in contact with the caudal peduncle spot (vs. absence of caudal spot in H. poecilioides, lateral stripe continued that is in contact with the caudal peduncle spot in H. ocasoensis. It has a rhomboid shaped caudal-peduncle spot that continues on to middle caudal-fin rays (vs. absence of caudal peduncle spot in H. poecilioides and caudal peduncle spot round and not continued on to middle caudal-fin rays in H. ocasoensis; and presence of hooks on all fins in mature males (vs. males with hooks on anal, pelvic and pectoral fins. Hyphessobrycon natagaima differs from H. ocasoensis, in addition to the above characters, by having four scale rows between the lateral line and the anal-fin origin (vs. six; three or four scale rows between the lateral line and the pelvic-fin insertions (vs. six; ten or eleven predorsal scales (vs. nine; i,9,i dorsal-fin rays (vs. ii,8,i; 18-20 branched anal-fin rays (vs. 21-22 and eleven branched pectoral-fin rays (vs. twelve. A key for the identification of Hyphessobrycon species present in the Magdalena River Basin is provided.

Three sympatric karyomorphs in the fish Astyanax fasciatus (Teleostei, Characidae do not seem to hybridize in natural populations

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Maressa Ferreira-Neto

2012-01-01

Full Text Available Ninety individuals of the characid fish Astyanax fasciatus (Cuvier, 1819 were collected at Água da Madalena stream (Botucatu, São Paulo, Brazil and analyzed for diploid chromosome number 2n and karyotype composition as well as for the chromosomal location of the 5S and 18S ribosomal DNA (rDNA. Whereas no chromosome differences were associated with sex, three different karyomorphs with diploid chromosome numbers 2n=46, 2n=48 and 2n=50 were found. No intermediate 2n numbers were discovered. The 2n=50 karyomorph showed some differences in 18S rDNA location compared to the two other karyomorphs. Finally, all specimens with the 2n=46 karyomorph showed the presence of a partly heterochromatic macro supernumerary chromosome, which was absent in all individuals with the two other karyomorphs. All these results suggest that indviduals of the three different karyomorphs are not likely to hybridize in the examined populations. Our findings strongly suggest the presence of three separate species (sensu biological species concept easily diagnosed on the basis of differences in the diploid chromosome numbers and other chromosomal markers.

A new species of Astyanax (Characiformes: Characidae) from Dolina Água Milagrosa, Rio Paraguai basin, Mato Grosso, Brazil.

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da Graça, W J; Oliveira, C A M; Lima, F C T; da Silva, H P; Fernandes, I M

2017-10-01

A new species of Astyanax is described from the upper Rio Paraguai basin, Mato Grosso State, Brazil. The new species can be distinguished from congeners by having the body intensely yellowish in life (v. silvery, reddish or lightly yellow) and by morphometric and meristics traits. Astyanax dolinae n. sp. cannot be assigned to any of the Astyanax species complex currently recognized for the genus. It is only known from the Dolina Água Milagrosa, a karstic sinkhole lake, entirely fed by groundwater, surrounded by Cerrado, the savannah-like vegetation of central South America. © 2017 The Fisheries Society of the British Isles.

Histología y morfometría del ojo del pez dulceacuícola Paracheirodon axelrodi (Characiformes: Characidae)

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Mario O Tovar; Martha J Obando; Edwin Gómez; María L Caldas; Hernán Hurtado

2009-01-01

El pez dulceacuícola P. axelrodi es de gran importancia comercial en la Orinoquía Colombiana y a nivel mundial, pero carece de estudios acerca de su visión. Se utilizaron diez individuos, con longitud total promedio de 2.7 cm (SD= 0.2, n= 20). Se realizaron cortes a 8 μm y se tiρeron con H-E. El tamaρo relativo del ojo es 9.8% (SD= 1.1, n= 20); el cristalino tiene un tamaρo relativo de 64.3% (SD= 4.9, n=20). Una esclerótica con tejido cartilaginoso. La retina está constitu...

Myxiops aphos, new characid genus and species (Characiformes: Characidae from the rio Lençóis, Bahia, Brazil

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Angela M. Zanata

Full Text Available Myxiops aphos, new genus and species, is described from a river in the eastern portion of Bahia State, Brazil. Myxiops is distinguished from all other characid genera by the combination of the following features: infraorbitals fused in a unique fashion, resulting always in less than six autogenous bones; a single tooth row in the premaxilla; presence of somewhat pedunculate teeth, expanded and compressed distally, with cusps similar in shape and perfectly aligned along distal margin; ventral margin of toothed portion of maxillary curved towards ventral margin of premaxilla and maxillary teeth forming a continuous series with premaxillary teeth; margins of pre- and postzygapophyses with projections anteriorly and posteriorly directed; accumulation of epithelial cells forming globular structures distributed over head and scales; and base of anal fin without scales covering basal portion of unbranched and anterior branched rays. The presence of these features in other characids is discussed.

Evolutionary history of the fish genus Astyanax Baird & Girard (1854 (Actinopterygii, Characidae in Mesoamerica reveals multiple morphological homoplasies

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Doadrio Ignacio

2008-12-01

Full Text Available Abstract Background Mesoamerica is one of the world's most complex biogeographical regions, mostly due to its complex geological history. This complexity has led to interesting biogeographical processes that have resulted in the current diversity and distribution of fauna in the region. The fish genus Astyanax represents a useful model to assess biogeographical hypotheses due to it being one of the most diverse and widely distributed freshwater fish species in the New World. We used mitochondrial and nuclear DNA to evaluate phylogenetic relationships within the genus in Mesoamerica, and to develop historical biogeographical hypotheses to explain its current distribution. Results Analysis of the entire mitochondrial cytochrome b (Cytb gene in 208 individuals from 147 localities and of a subset of individuals for three mitochondrial genes (Cytb, 16 S, and COI and a single nuclear gene (RAG1 yielded similar topologies, recovering six major groups with significant phylogeographic structure. Populations from North America and Upper Central America formed a monophyletic group, while Middle Central America showed evidence of rapid radiation with incompletely resolved relationships. Lower Central America lineages showed a fragmented structure, with geographically restricted taxa showing high levels of molecular divergence. All Bramocharax samples grouped with their sympatric Astyanax lineages (in some cases even with allopatric Astyanax populations, with less than 1% divergence between them. These results suggest a homoplasic nature to the trophic specializations associated with Bramocharax ecomorphs, which seem to have arisen independently in different Astyanax lineages. We observed higher taxonomic diversity compared to previous phylogenetic studies of the Astyanax genus. Colonization of Mesoamerica by Astyanax before the final closure of the Isthmus of Panama (3.3 Mya explains the deep level of divergence detected in Lower Central America. The colonization of Upper Mesoamerica apparently occurred by two independent routes, with lineage turnover over a large part of the region. Conclusion Our results support multiple, independent origins of morphological traits in Astyanax, whereby the morphotype associated with Bramocharax represents a recurrent trophic adaptation. Molecular clock estimates indicate that Astyanax was present in Mesoamerica during the Miocene (~8 Mya, which implies the existence of an incipient land-bridge connecting South America and Central America before the final closure of the Isthmus of Panama (~3.3 Mya.

Uso do alimento por duas espécies simpátricas de Moenkhausia (Characiformes, Characidae em um riacho da Região Centro-Oeste do Brasil Food used by two sympatric species of Moenkhausia (Characiformes, Characidae, in a stream of center-western Brazil

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Raffael M Tófoli

2010-09-01

Full Text Available Esse estudo avaliou sazonalmente a dieta de Moenkhausia dichroura (Kner, 1858 e M. sanctaefilomenae (Steindachner, 1907, coletadas em simpatria no riacho Cancela, Mato Grosso, Brasil. Independente do período hidrológico, alimentos de origem alóctone predominaram na dieta de ambas as espécies (>50% do total de itens consumidos, sendo insetos terrestres o recurso principal, embora, para M. dichroura insetos aquáticos tenham contribuído na dieta também. Hymenoptera (Formicidae foi o alimento mais consumido, sendo ambas as espécies caracterizadas como insetívoras terrestres. A dieta restrita dessas espécies é confirmada pelos baixos valores de amplitude de nicho trófico: Ba=0,26 para M. dichroura em ambos os períodos e Ba=0,41 no período de seca e 0,38 no período de chuva, para M. sanctaefilomenae. A sobreposição alimentar foi elevada no período de chuva (Ojk=0,75 e apresentou valor intermediário no período de seca (Ojk=0,41, evidenciando maior partilha do alimento entre as espécies neste período.This study evaluated the seasonality in the diet of Moenkhausia dichroura (Kner, 1858 and M. sanctaefilomenae (Steindachner, 1907, sympatric species of the Cancela stream, state of Mato Grosso, Brazil. Regardless of the seasonal period, allochthonous food source predominated in the diet of both species (>50% of all items consumed and among these terrestrial insects were the dominant resource. However, aquatic insects were important in the diet of M. dichroura as well. Hymenoptera (Formicidae was the dominant item to both species, thus they were characterized as terrestrial insectivorous. The restricted diet of these species is confirmed by the trophic niche breadth, whose values were in general low: Ba=0.26 to M. dichroura in both periods and Ba=0.41 and 0.38 in the dry and rainy period, respectively, to M. sanctaefilomenae. The feeding overlap was high in the rainy period (Ojk=0.75 and intermediate in the dry period (Ojk=0.41, showing that the food partitioning between species was larger in this period.

Morphological variation in populations of Tetragonopterus argenteus Cuvier, 1817 (Characiformes, Characidae from Madeira and Paraguay river basins Variação morfológica em populações de Tetragonopterus argenteus Cuvier, 1817 (Characiformes, Characidae das bacias dos rios Madeira e Paraguai

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Willian Massaharu Ohara

2007-10-01

Full Text Available The saua Tetragonopterus argenteus is endemic to South America. It has a wide geographic distribution and occurs in different Brazilian basins, such as those of the Madeira and Paraguay rivers. In this work, it was noticed that populations from these basins have morphological variations between them, indicating a possible geographic isolation. Specimens were studied using twelve morphological characters that were submitted to the canonical variates and body proportion analysis. In the canonical variate analysis, the populations from the Madeira and Paraguay river basins were differentiated by caudal peduncle depth, eye diameter, pre-ventral distance, body height, snout length and head length. In the body proportion analysis, the population of Madeira river basin presented head length, orbital diameter, pre-dorsal distance, dorsal-fin length, pre-ventral distance, body height and caudal peduncle height, smaller than those of the population from Paraguay river basin. These results allowed the recognition of intra-specific variation amplitude, that could become an important instrument for management and conservation of this species. O sauá Tetragonopterus argenteus é endêmico da América do Sul, apresenta ampla distribuição geográfica e ocorre em várias bacias brasileiras, entre elas as dos rios Madeira e Paraguai. Neste trabalho foi observado que as populações dessas bacias apresentam variações morfológicas que, provavelmente, representam isolamento geográfico. Exemplares foram estudados através de 12 caracteres morfológicos e submetidos às análises de variáveis canônicas e de proporções corporais. Na análise das variáveis canônicas, as populações das bacias dos rios Madeira e Paraguai diferenciaram-se pelo diâmetro do olho, distância pré-ventral, altura do corpo, comprimento do focinho, altura do pedúnculo caudal e comprimento da cabeça. Na análise das proporções corporais, a população da bacia do rio Madeira apresentou comprimento da cabeça, diâmetro do olho, distância pré-dorsal, comprimento da base da nadadeira dorsal, distância pré ventral, altura do corpo e altura do pedúnculo caudal, menores que os das populações da bacia do rio Paraguai. Esses resultados possibilitam o reconhecimento da amplitude da variação intra-específica, que poderá ser um importante instrumento para o manejo e conservação dessa espécie de peixe.

Aerocistite aguda induzida por tioglicolato, lipolisacarídeo e Aeromona hydrophila inativada em Piaractus mesopotamicus: efeitos hematológicos

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Julieta Rodini Engrácia de Moraes

2012-10-01

Full Text Available Os efeitos da injeção de tioglicolato, lipolissacarídio de Escherichia coli e Aeromonas hydrophila inativada na bexiganatatória de pacus, Piaractus mesopotamicus (Characidae foram avaliados quanto às respostas de células vermelhas,leucócitos e trombócitos do sangue. Ensaios quantitativos de eritrócitos, leucócitos e trombócitos foram realizados6, 24 e 48 h após os estímulos e comparados com peixes que receberam solução salina 0,65% pela mesma via. Peixes inoculados com A. hydrophila apresentaram redução do número de eritrócitos e da taxa de hemoglobina enquanto ohematócrito aumentou 6 h após o estímulo. Os resultados mostraram que o tioglicolato e o LPS também induziram redução da hemoglobina e aumento do hematócrito. A contagem de trombócitos diminuiu 6 h após a inoculação deA. hydrophila inativada e aumentou 48 horas após a injeção de LPS. A contagem de leucócitos aumentou 6 h após ainoculação de A. hydrophila enquanto a de linfócitos a leucócitos granulares PAS positivos (PAS_LG diminuiu 24 hdepois. Peixes injetados com tioglicolato o LPS apresentaram aumento do número de LG_PAS em relação aos inoculadoscom A. hydrophila inativada ou grupo controle. A contagem de monócitos não foi afetada pelos diferentes agentes.

Histologia e ultraestrutura do rim e rim cefálico do pacu

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Gerlane M. Costa

2012-05-01

Full Text Available O pacu, Piaractus mesopotamicus, é um teleósteo da Família Characidae, intensivamente cultivado no Brasil devido sua rusticidade, crescimento rápido e fácil adaptação. O conhecimento morfológico dos sistemas corpóreos, incluído órgãos linfóide, se faz necessário, para uma melhor produção no cultivo de peixes, fornecendo subsídios na manutenção dos estoques. O objetivo deste estudo foi descrever morfologicamente o rim e rim cefálico de Piaractus mesopotamicus, analisando os perfis celulares de cada órgão com o uso de microscopia de luz e microscopia eletrônica de transmissão. O resultado da análise macroscópica mostrou que a localização do rim e rim cefálico são as mesmas encontradas na maioria dos teleósteos. O rim apresentou uma forma em "H", onde a região média se expandia sobre a bexiga natatória. O rim cefálico se apresentou como uma dilatação na região cranial do rim, mostrando-se bem visível. Na microscopia eletrônica de transmissão também foram observadas similaridades ultraestruturais com outros teleósteos. Observando nossos resultados concluímos que histologicamente e ultraestruturalmente, os órgãos linfóides rim e rim cefálico de Piaractus mesopotamicus são similares aos de outros teleósteos.

A successful case of biological invasion: the fish Cichla piquiti, an Amazonian species introduced into the Pantanal, Brazil

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EK. Resende

Full Text Available The "tucunaré", Cichla piquiti, an exotic Amazonian fish has become established along the left bank of the Paraguay River in the Pantanal. It was introduced by escaping from culture ponds in the Upper Piquiri River and spread downstream, along the lateral flooded areas of that river, continuing through the clear waters of the left bank of the Paraguay River and reaching south as far as the Paraguai Mirim and Negrinho rivers. Adult spawners have been found in the region, meaning that it is a self-sustained population. Reproduction occurs in the period of low waters. They were found feeding on fishes of lentic environments belonging to the families Characidae, Cichlidae and Loricariidae. Until the end of 2004, its distribution was restricted to the left bank of the Paraguay River, but in March 2005, some specimens were found on the right bank, raising a question for the future: what will be the distribution area of the tucunaré in the Pantanal? Information about its dispersion is increasing: it is known to be in the Tuiuiú Lake, Pantanal National Park and in the Bolivian Pantanal, all of them on the right bank of the Paraguay River. The hypothesis that the "tucunaré" could not cross turbid waters, such as in the Paraguay River, was refuted by these recent findings. Possibly, the tucunaré's capacity to lay more than one batch of eggs in a reproductive period, as well as its care of eggs and young, lead them to establish themselves successfully in new environments, as has been observed in the Pantanal and other localities.

Spawning and nursery habitats of neotropical fish species in the tributaries of a regulated river

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Makrakis, Maristela Cavicchioli; da Silva, Patrícia S.; Makrakis, Sergio; de Lima, Ariane F.; de Assumpção, Lucileine; de Paula, Salete; Miranda, Leandro E.; Dias, João Henrique Pinheiro

2012-01-01

This chapter provides information on ontogenetic patterns of neotropical fish species distribution in tributaries (Verde, Pardo, Anhanduí, and Aguapeí rivers) of the Porto Primavera Reservoir, in the heavily dammed Paraná River, Brazil, identifying key spawning and nursery habitats. Samplings were conducted monthly in the main channel of rivers and in marginal lagoons from October through March during three consecutive spawning seasons in 2007-2010. Most species spawn in December especially in Verde River. Main river channels are spawning habitats and marginal lagoons are nursery areas for most fish, mainly for migratory species. The tributaries have high diversity of larvae species: a total of 56 taxa representing 21 families, dominated by Characidae. Sedentary species without parental care are more abundant (45.7%), and many long-distance migratory fish species are present (17.4%). Migrators included Prochilodus lineatus, Rhaphiodon vulpinus, Hemisorubim platyrhynchos, Pimelodus maculatus, Pseudoplatystoma corruscans, Sorubim lima, two threatened migratory species: Salminus brasiliensis and Zungaro jahu, and one endangered migratory species: Brycon orbignyanus. Most of these migratory species are vital to commercial and recreational fishing, and their stocks have decreased drastically in the last decades, attributed to habitat alteration, especially impoundments. The fish ladder at Porto Primavera Dam appears to be playing an important role in re-establishing longitudinal connectivity among critical habitats, allowing ascent to migratory fish species, and thus access to upstream reaches and tributaries. Establishment of Permanent Conservation Units in tributaries can help preserve habitats identified as essential spawning and nursery areas, and can be key to the maintenance and conservation of the fish species in the Paraná River basin.

Fish community structure in freshwater karstic water bodies of the Sian Ka'an Reserve in the Yucatan peninsula, Mexico

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Zambrano, L.; Vazquez-Dominguez, E.; Garcia-Bedoya, D.; Loftus, W.F.; Trexler, J.C.

2006-01-01

We evaluated the relationship between limnetic characteristics and fish community structure (based on species richness, abundance and individual size) in contrasting but interconnected inland aquatic habitats of freshwater karstic wetlands in the Yucatan peninsula, Mexico. In the western hemisphere, freshwater karstic wetlands are found in south-eastern Mexico, northern Belize, western Cuba, Andros Island, Bahamas and the Everglades of southern Florida. Only in the Everglades have fish communities been well described. Karstic wetlands are typically oligotrophic because calcium carbonate binds phosphorus, making it relatively unavailable for plants. Fourteen permanent and seasonally flooded water bodies were sampled in both wet and dry seasons in Sian Ka'an Biosphere Reserve, in the Mexican state of Quintana Roo. Water systems were divided by morphology in four groups: cenotes with vegetation (CWV), cenotes without vegetation (CNV), wetlands (WTL), and temporal cenotes (TPC). Discriminant analysis based on physical characteristics such as turbidity, temperature, depth and oxygen confirmed that these habitats differed in characteristics known to influence fish communities. A sample-based rarefaction test showed that species richness was significantly different between water systems groups, showing that WTL and CWV had higher richness values than CNV and TPC. The most abundant fish families, Poeciliidae, Cichlidae and Characidae, differed significantly in average size among habitats and seasons. Seasonal and inter-annual variation, reflecting temporal variation in rainfall, strongly influenced the environmental differences between shallow and deep habitats, which could be linked to fish size and life cycles. Five new records of species were found for the reserve, and one new record for Quintana Roo state. ?? 2006 by Verlag Dr. Friedrich Pfeil.

Anatomia funcional e morfometria dos intestinos e dos cecos pilóricos do teleostei (pisces de água doce Brycon orbignyanus (Valenciennes, 1849

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Seixas Filho José Teixeira de

2000-01-01

Full Text Available O objetivo do presente trabalho foi estudar a anatomia funcional e a morfometria comparativas nos intestinos médio e posterior e nos cecos pilóricos da piracanjuba (Brycon orbignyanus Valenciennes, 1849 (Characiformes, Characidae, Bryconinae. Foram conduzidos estudos anatomofuncionais e morfométricos nos intestinos médio e posterior e nos cecos pilóricos dessa espécie com hábito alimentar onívoro. Constatou-se, por meio destes estudos, que o padrão de enrolamento das alças intestinais em arranjo em N apresentou, na segunda classe de tamanho, freqüentes variações no intestino médio, mas foi compatível com os de outras espécies de hábitos alimentares similares. Os estudos da morfometria mostraram que o comprimento total do intestino e das alças intestinais e seus calibres, provavelmente, exercem função específica na absorção dos nutrientes. As relações entre o arranjo das pregas da mucosa e a velocidade de transporte do alimento no intestino médio sugerem que os padrões transversal e oblíquo retardam o avanço do alimento em sentido aboral, possibilitando maior período digestivo e melhor aproveitamento dos nutrientes, contribuindo para a preparação do bolo fecal. O comprimento e o calibre dos cecos pilóricos aumentam com o desenvolvimento do peixe, e o seu padrão de mucosa possui características anatômicas semelhantes às do intestino.

Conserved number of U2 snDNA sites in Piabina argentea, Piabarchus stramineus and two Bryconamericus species (Characidae, Stevardiinae

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Diovani Piscor

2018-03-01

Full Text Available ABSTRACT The chromosomal location of 5S rRNA and U2 snRNA genes of Piabina argentea, Piabarchus stramineus and two Bryconamericus species from two different Brazilian river basins were investigated, in order to contribute to the understanding of evolutionary characteristics of these repetitive DNAs in the subfamily Stevardiinae. The diploid chromosome number was 2n = 52 for Bryconamericus cf. iheringii, Bryconamericus turiuba, Piabarchus stramineus and Piabina argentea. The 5S rDNA clusters were located on one chromosome pair in P. stramineus and B. cf. iheringii, and on two pairs in B. turiuba and P. argentea. The U2 snDNA clusters were located on the one pair in all species. Two-color FISH experiments showed that the co-localization between 5S rDNA and U2 snDNA in P. stramineus can represent a marker for this species. Thus, the present study demonstrated that the number of U2 snDNA clusters observed for the four species was conserved, but particular characteristics can be found in the genome of each species.

Ontogenic events and swimming behavior of larvae of the characid fish Salminus brasiliensis (Cuvier (Characiformes, Characidae under laboratory conditions

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José Enemir dos Santos

2002-03-01

Full Text Available The larval ontogeny and swimming behavior of the characid fish Salminus brasiliensis (Cuvier, 1816 were studied under experimental laboratory conditions, from hatching to yolk absorption. At day 1, the larvae were transparent, with sparse dendrite chromatophores and a well-developed adhesive organ on the head. The retinal epithelial cells were initiating pigmentation. The branchial arches were at the initial phase of differentiation. The larvae were able to perform only vertical displacements and, when resting on the tank bottom, remained in lateral decumbency, in groups of 3 to 15 larvae. On day 2, the mouth was open, with conical teeth, and the digestive tube presented lumen and folded mucosa. The gaseous bladder and pectoral fins also were in differentiation. The larvae performed vertical and horizontal movements, adhered to the water surface by means of the adhesive organ or formed groups of three to six on the tank bottom. On day 3, the adhesive organ turned dorsal, the retina was pigmented, the digestive tube mucosa showed goblet cells, and the yolk sac exhausted. The larvae were now scattering in the water column forming no groups on the bottom.

Perulernaea gamitanae (Copepoda: Lernaeidae parasitizing tambaqui (Colossoma macropomum (Characidae and the hybrids tambacu and tambatinga, cultured in northern Brazil

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M. Tavares-Dias

2011-08-01

Full Text Available The infestation rate in Colossoma macropomum, hybrid tambacu (C. macropomum x Piaractus mesopotamicus and hybrid tambatinga (C. macropomum x Piaractus brachypomum with Perulernaea gamitanae Thatcher and Paredes, 1985 from two fish farms in Amapá State, Brazil was studied. Lernaeid parasites (n=2887 were collected mainly on the tongue and the mouth cavity and also on cartilage of gill arches and filaments. Inflammation and fibrous nodules were observed on the attachment sites of the parasites. The infestation rate varied according to the fish farm and host. The prevalence of P. gamitanae was of 100% in hosts from one fish farm and was lower in the other fish farm. Higher intensity of P. gamitanae occurred in hybrids tambacu and tambatinga, but despite the high prevalence its intensity was moderate. This is the first report on epidemiology of P. gamitanae in cultured fishes from Brazilian Amazonia, and the occurrence of this crustacean parasite in two new hosts, the hybrids tambacu and tambatinga.

A new species of Astyanax (Ostariophysi: Characidae from the headwaters of the arheic Río Sucuma, Catamarca, Northwestern Argentina

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Guillermo E. Terán

2017-06-01

Full Text Available ABSTRACT A new species of Astyanax is described from the arheic system of Río Sucuma, in Catamarca, Northwestern Argentina. The new species is distinguished from its congeners by a combination of characters including the presence of a broad vertical humeral spot, absence of maxillary teeth, and absence of circuli in posterior field of scales. Furthermore, this species is distinguished by the orbital diameter, head length, branched anal-fin rays, perforated lateral-line scales, transverse scales, dentary teeth with abrupt decrease in size. This species is, to date, the single known fish endemic of Río Sucuma basin.

UNA NUEVA ESPECIE DE PEZ DEL GÉNERO HEMIBRYCON (CHARACIFORMES: CHARACIDAE DEL ALTO RÍO ATRATO, NOROCCIDENTE DE COLOMBIA

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ROMÁN-VALENCIA CÉSAR

2007-06-01

Full Text Available Se describe una nueva especie de Hemibrycon para la cuenca alta del río Atrato,al noroccidente de Colombia. La especie se distingue de sus congéneres por supequeño tamaño (de las órbitas y la parte ventral de la mandíbula superior planos, las mandíbulas noson iguales: la mandíbula superior sobresale con relación a la inferior, aleta pélvicalarga y su extremo alcanza el origen de la aleta anal, bajo número de vértebras yde radios ramifi cados en la aleta anal. Se incluyen datos ecológicos propios delambiente acuático del nuevo taxón y una clave para las especies de Hemibrycon deColombia.

Pacu fish (Cuvier, 1818 (Characiformes: Characidae landed in Porto Velho (Rondônia fish market from 1985 to 2004

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Maria Alice Leite Lima

2008-09-01

Full Text Available This study evaluated various aspects of the profile of pacu (Mylossoma spp., Myleus spp., Metynnis spp. fish marketed on the Cai N’água floating platform of Porto Velho (RO from 1985 to 2004. Inter- and intra-annual variations in yield, variation in fish length and general characteristics of the fishing are reported. The annual pacu yield ranged from 33,000kg to 146,000kg (average = 86,585kg, representing from 6.6% to 20.45% of the total landings in the studied period. These variations followed the hydrologic cycle, and the greatest yields were recorded in the years following the highest water levels. The monthly production ranged from 0 to 42,366kg (average = 5,772kg and it was related to reproductive migration. The pacu presented variations in standard length from 14 to 20cm (18.72cm ± 3.69, mean ± sd. The fishing was based on the use of seines and gill nets and the main environments of capture were tributaries of the low Madeira River (Jamari, Oropiara, Machado and Novo Aripuanã. The CPUE calculated for 2003 to 2005 was 15kg*fisherman 1day-1 (sd = ±21. The results show that the category constituted during this period an important resource for local commercial exploitations, as verified in other regions of the Amazon.

Biomonitoring of genotoxicity using micronuclei assay in native population of Astyanax jacuhiensis (Characiformes: Characidae) at sites under petrochemical influence

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Torres de Lemos, Clarice [Divisao de Biologia, Programa de Pesquisas Ambientais, Departamento de Laboratorios, Fundacao Estadual de Protecao Ambiental Henrique Luis Roessler (FEPAM), Avenida Dr. Salvador Franca, 1707, 90690-000, Porto Alegre, RS (Brazil)], E-mail: claricetl@fepam.rs.gov.br; Almeida Iranco, Fabio de; D' Avila de Oliveira, Nanci Cristina; Dornelles de Souza, Getulio [Divisao de Biologia, Programa de Pesquisas Ambientais, Departamento de Laboratorios, Fundacao Estadual de Protecao Ambiental Henrique Luis Roessler (FEPAM), Avenida Dr. Salvador Franca, 1707, 90690-000, Porto Alegre, RS (Brazil); Guimaraes Fachel, Jandyra Maria [Instituto de Matematica, Departamento de Estatistica, Universidade Federal do Rio Grande do Sul. Av. Bento Goncalves, 9500, 91509-9000, Porto Alegre, RS (Brazil)

2008-11-15

Bom Jardim brook is a small stream that flows through an area under the influence of a Petrochemical Complex, demanding control over its quality, so a genotoxic evaluation was performed. This study was conducted in situ, based on previous analysis on the same subject. These were performed both in vitro, with Salmonella typhimurium and human lymphocytes, and in vivo, using bioassays with fish exposed to water from the study area. The purpose of this research was to assess the quality of the aquatic environment and possible effects from petrochemical pollution to surrounding native populations. Micronuclei (MNE) and nuclear abnormalities (NA) frequencies in peripheral blood of Astyanax jacuhiensis, a native fish species collected from the study area, were used as biomarkers. Study period was from summer/99 to spring/2001, using samples obtained seasonally at two ponds upstream from the industrial area (BJN and BJPa) and two sites in Bom Jardim brook (BJ002 and BJ000), which are subject to Complex influence. MNE and NA frequencies found in individuals from BJ002 and BJ000 were similar, showing positive genotoxic responses related to control sites BJN and BJPa. No differential sensitivity could be verified for micronuclei induction between genders of A. jacuhiensis in the studied population. This study showed that sites subject to petrochemical influence were under higher genotoxic impact. Biomarkers adequacy to the case and the sensitivity of A. jacuhiensis for water monitoring could be also inferred.

Biomonitoring of genotoxicity using micronuclei assay in native population of Astyanax jacuhiensis (Characiformes: Characidae) at sites under petrochemical influence

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Torres de Lemos, Clarice; Almeida Iranco, Fabio de; D'Avila de Oliveira, Nanci Cristina; Dornelles de Souza, Getulio; Guimaraes Fachel, Jandyra Maria

2008-01-01

Bom Jardim brook is a small stream that flows through an area under the influence of a Petrochemical Complex, demanding control over its quality, so a genotoxic evaluation was performed. This study was conducted in situ, based on previous analysis on the same subject. These were performed both in vitro, with Salmonella typhimurium and human lymphocytes, and in vivo, using bioassays with fish exposed to water from the study area. The purpose of this research was to assess the quality of the aquatic environment and possible effects from petrochemical pollution to surrounding native populations. Micronuclei (MNE) and nuclear abnormalities (NA) frequencies in peripheral blood of Astyanax jacuhiensis, a native fish species collected from the study area, were used as biomarkers. Study period was from summer/99 to spring/2001, using samples obtained seasonally at two ponds upstream from the industrial area (BJN and BJPa) and two sites in Bom Jardim brook (BJ002 and BJ000), which are subject to Complex influence. MNE and NA frequencies found in individuals from BJ002 and BJ000 were similar, showing positive genotoxic responses related to control sites BJN and BJPa. No differential sensitivity could be verified for micronuclei induction between genders of A. jacuhiensis in the studied population. This study showed that sites subject to petrochemical influence were under higher genotoxic impact. Biomarkers adequacy to the case and the sensitivity of A. jacuhiensis for water monitoring could be also inferred

Hyphessobrycon taphorni y H. eschwartzae (Teleostei: Characidae dos nuevas especies de peces de la cuenca del río Madre de Dios, Perú Hyphessobrycon taphorni and H. eschwartzae (Teleostei: Characidae two new species of fish in the basin of Madre de Dios river, Peru

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Carlos A. García-Alzate

2013-06-01

Full Text Available Hyphessobrycon con 129 especies válidas, es un género de peces que presenta una gran diversidad de especies dentro de la ictiofauna neotropical, alcanza su mayor diversidad en la cuenca del Amazonas con alrededor del 70% de estas especies, es altamente apetecido por los acuaristas por su belleza y colorido y aún se están conociendo nuevas especies. Las medidas de los ejemplares se tomaron punto a punto con calibrador digital. Observaciones de las estructuras óseas y de cartílago se hicieron sobre muestras clareadas y teñidas (C&T. Las relaciones morfométricas entre especies fueron exploradas mediante un análisis de componentes principales (ACP en 21 variables. Se des- criben dos especies nuevas, Hyphessobrycon taphorni y H. eschwartzae de la cuenca del río Madre de Dios, Perú. Hyphessobrycon taphorni sp. n. puede distinguirse por: el número de radios de la aleta dorsal (iii, 8, cuatro a cinco escamas con poros en la línea lateral, uno a dos dientes en la fila externa del premaxilar, siete a ocho dientes en la fila interna del premaxilar, por la longitud del pedúnculo caudal (11.4-16.4% LE, por el número de escamas laterales (28- 29; excepto en H. loretoensis con 29-30 y por la ausencia de una mancha humeral (vs. presencia, se diferencia de H. loretoensis por el número de escamas entre la línea lateral y la aleta anal (cuatro vs. tres y los dientes del maxilar (dos vs. tres a cuatro, y se distingue de H. agulha por el número de radios ramificados en las aletas pectorales (11- 12 vs. 9-10. Hyphessobrycon eschwartzae sp. n. puede distinguirse por el número de radios simples en la aleta anal (iv, por 13 a 15 dientes en el dentario; 6 dientes en la fila interna del premaxilar; tres dientes en la fila externa del premaxilar (excepto en H. heterorhabdus y H. loretoensis con tres a cuatro, se diferencia de H. loretoensis por el número: de escamas con poros en la línea lateral (siete vs. nueve a diez; escamas entre la línea lateral y la aleta dorsal (cinco vs. tres a cuatro, se diferencia de H. agulha por el número de escamas: laterales (30-31 vs. 33-34, predorsales (9 vs. 10, dientes en el maxilar (cuatro vs. cero a uno por presentar en vida una banda lateral roja por encima de la banda oscura que se extiende desde la parte posterior del opérculo hasta el pedúnculo caudal (vs. ausencia, y por la presencia de ganchos óseos en machos maduros solo en la aleta anal (vs. todas las aletas incluye la caudal.Hyphessobrycon with 129 valid species, is a genus of fish that has a great diversity of species in the Neotropical ichthyofauna, reaches its greatest diversity in the Amazon basin with about 70% of these species, is highly desired by hobbyists because of their beauty and color, and are still meeting new species. We analyzed specimens from the Departamento de Ictiología, Museo de Historia Natural de la Universidad Mayor de San Marcos, Lima, Perú (MUSM; and measurements of the specimens were taken point to point with digital calipers. Observations of bone and cartilage structures were made on cleared and stained (C&S samples. The morphometric relationships between species using 21 variables were explored using a principal component analysis (PCA. Here we describe two new species, Hyphessobrycon taphorni and H. eschwartzae from the Madre de Dios River drainage, Peru. Hyphessobrycon taphorni sp. n. can be distinguished by the number of dorsal-fin rays (iii, 8, by the number of: pored lateral-line scales (4-5, teeth in the outer premaxillary row (1-2, teeth in the inner premaxillary row (7-8, by: the caudal-peduncle length (11.4-16.4% SL, number of lateral scales (28-29, except from H. loretoensis which has 29-30 and absence of a humeral spot (vs. present, it differs from H. loretoensis by the number of: scales between the lateral line and the anal fin origin (4 vs. 3 and maxillary teeth (2 vs. 3-4, and it differs from H. agulha by the number of branched pectoral-fin rays (11-12 vs. 9-10. Hyphessobrycon eschwartzae sp. n. is distinguished by the number of: simple anal-fin rays (iv, teeth on the dentary (13-15, teeth in the inner premaxillary row (6, teeth in the outer premaxillary row (3, except from H. heterorhabdus and H. loretoensis which have 3-4; it differs from H. loretoensis by the number of: pored lateral-line scales (7 vs. 9-10, scales between the lateral line and the dorsal-fin origin (5 vs. 3-4; it differs from H. agulha in the number of lateral scales (30-31 vs. 33-34, by the number of: predorsal scales (9 vs. 10, maxillary teeth (4 vs. 0-1; in having in life a red lateral stripe above the dark lateral stripe that extends from the posterior part of the opercle to the caudal peduncle (vs. absent and by the presence of bony hooks in mature males only on the anal fin (vs. hooks on all fins, including the caudal.

Performance and bromatologic analysis of red tail lambari Astyanax sp F (Pisces: characidae submitted to the smoking process / Rendimento e análise bromatológica do lambari do rabo vermelho Astyanax sp F (Pisces: characidae submetido ao processo de defumação

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Carlos Eduardo Weirich

2009-12-01

Full Text Available The aim of this study was to evaluate the time of hot smoked and the influence of carcass quality of the red tail lambari Astyanax sp F. Sixty lambaris, eviscerated with head, skin, bones, spinal column, fins, however, without scale. With a medium weight and length of 22.22±4.32g and 11.32±00.63cm were utilized. The animals were submitted to humid salted (25% of sodium chloride for 45 minutes and condiments, been later hot smoked for a period of 90, 180, 270, 360 min. After the smoking process, the fish were weighted and later the humidity tenor, gross protein, lipids and mineral matter of the carcass of the animals were calculated. The results showed differences (P O objetivo do presente trabalho foi avaliar o tempo de defumação a quente e a influência sobre a qualidade de carcaça de lambaris Astyanax sp. F. Foram utilizados 60 lambaris, com peso e comprimento médio de 22,22±4,32g e 11,32±0,63cm, eviscerados e com cabeça, pele, espinhas, coluna vertebral, nadadeiras, porém, sem escamas. Os animais foram submetidos à salga úmida (25% de cloreto de sódio por 45 minutos e condimentos, sendo posteriormente defumados a quente, por um período de 90, 180, 270 e 360min. Após o processo de defumação, os peixes foram pesados e posteriormente calculados os teores de umidade, proteína bruta, lipídeos e matéria mineral da carcaça dos animais. Os resultados mostraram diferenças (P 0,05 entre os diferentes tempos de defumação. Portanto, conclui-se que para o Astyanax sp F o tempo de defumação de 225min7seg é o período de defumação indicado para o melhor produto final.

Descripción del cráneo de Bramocharax caballeroi Contreras & Rivera 1985 (Pisces, Characidae), pez endémico del Lago de Catemaco, Veracruz, México Description of the skull of Bramocharax caballeroi Contreras & Rivera 1985 (Pisces, Characidae), endemic fish to Catemaco Lake, Veracruz, Mexico

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Martha Elena Valdez-Moreno; Salvador Contreras-Balderas

2009-01-01

El género Bramocharax se distribuye del centro-norte de Centro América a México. Hasta este momento se conoce a Bramocharax bransfordi de Nicaragua y Costa Rica, a B. dorioni y B. baileyi de Guatemala y a B. caballeroi del lago de Catemaco, Veracruz, México. El trabajo tuvo por objetivo estudiar detalladamente el cráneo de Bramocharax caballeroi a partir del análisis de 37 topotipos de diferentes tallas y compararlo con otras especies relacionadas. B. caballeroi presenta 58 huesos en su cráne...

Coeficientes de digestibilidad aparente de harina de pescado peruana y maíz amarillo duro para Colossoma macropomum (Actinopterygii, Characidae

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Felix Walter Gutierrez

2008-12-01

Full Text Available Los Coeficientes de Digestibilidad Aparente (CDA de la materia seca (MS, proteína cruda (PC, lípido crudo(LC y energía bruta (EB de los ingredientes alimenticios harina de pescado peruana (HPP y de maíz amarillo duro (MAD fueron determinados en juveniles de Colossoma macropomum (150,0 ± 25,5 g. En el experimento la dieta de referencia se mezcló con cada uno de los ingredientes prueba en una relación de 70:30. El óxido crómico se usó como indicador inerte. La dieta de referencia y las dietas prueba fueron suministradas a C. macropomum, criada a 27 ºC, 7 mg/L de oxígeno disuelto y pH entre 7,5. Las muestras fecales fueron colectadas por sifoneo. Los CDA para MS, PC, LC y EB de la HPP fueron de 88,06 ± 0,83%, 87,08 ± 1,34%, 85,87 ± 2,69 y 87,29 ± 1,57% respectivamente. Igualmente los CDA para MS, PC, LC y EB del MAD fueron de 82,38 ± 1,02%, 75,46 ± 1,53%, 76,17 ± 2,43% y 75,04 ± 1,80% respectivamente. La energía digestible aparente calculada fue de 3950 Kcal/kg para la HPP y 2830 kcal/kg para el MAD. Se concluye que C. macropomum digiere mejor las fracciones proteicas y energéticas de la HPP. Al mismo tiempo muestra que digiere también la fracción energética del MAD, proveniente de los carbohidratos solubles.

Dynamics and cytochemistry of oogenesis in Astyanax fasciatus (Cuvier (Teleostei, Characiformes, Characidae from Rio Sapucaí, Minas Gerais State, Brazil

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José Antônio Dias Garcia

2001-12-01

Full Text Available Oogenesis involves a set of transformations which are undergone by female germ cells These cells change into oogonias and then into mature oocytes. Sexually mature female fish were collected monthly, during one year, from the Sapucaí River, a tributary of the Rio Grande, which is part of the Furnas Reservoir in the state of Minas Gerais. During the several stages of maturation, we observed small round oogonias with a large nucleus, a single nucleolus, and weakly stained cytoplasm with eosinophilic granules. The primary oocytes showed a large basophilic nucleus, with a developed peripheral nucleolus and a reduced cytoplasm. The previtellogenic oocytes presented voluminous cytoplasm and nucleus with several small peripheral nucleoli. The oocytes underwent vitellogenesis with the development of the zona radiata and the follicle cells. Their cytochemical reactions indicated that the two layers of the zona radiata of A. fasciatus contained proteins and polysaccharides. The initially squamous follicle cells, became cuboidal. In mature oocytes, the nucleus moved toward the periphery, next to the micropyle, and the yolk granules formed by proteins, fulfilled the cytoplasm. The clear unstained vesicles are likely to be the cortical alveoli in the perivitelline region.

Haematological characteristics of Brazilian Teleosts: III. Parameters of the hybrid tambacu (Piaractus mesopotamicus Holmberg x Colossoma macropomum Cuvier (Osteichthyes, Characidae

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Marcos Tavares-Dias

2000-12-01

Full Text Available Fifty six specimens of the hybrid "tambacu" (Piaractus mesopotamicus Holmberg, 1887 male x Colossoma macropomum Cuvier, 1818 female were collected from fishfarm of Guariba, São Paulo, to evaluate their haematology. Fishes presented 400.0 to 3,100.0 g total weight and 20.0 to 52.0 cm total length. Haemoglobin, haematocrit, mean corpuscular haemoglobin content (MCHC and percentage of defense blood cells including leucocytes and thrombocytes, were studied. Statistical analysis showed positive correlation (P<0.01 between haematocrit, MCHC and haemoglobin rate. Nevertheless, thrombocytes and lymphocytes showed negative correlation (P<0.01.

Effects of chromium supplementation on the infrapopulations of Anacanthorus penilabiatus (Monogenoidea and Piscinoodinium pillulare (Dinoflagellida parasites of Piaractus mesopotamicus (Characidae

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Rodrigo Yudi Fujimoto

2010-08-01

Full Text Available This study evaluated the parasitism by Anacanthorus penilabiatus (Monogenoidea and Piscinoodinium pillulare (Dinoflagellida in the gills of "pacu", Piaractus mesopotamicus supplemented with chromium in the diet. Randomised delineation by using factorial scheme (4x2x2 for Monogenoidea and 4x2x3 for Dinoflagellate with four levels of chromium (0, 6, 12, 18mg/kg diet, two stocking densities (4kg/m³ and 20kg/m ³, two classes of length (higher and lower than 17 cm for a period of 7, 60 and 90 days, and four replicates was used. The fishes in low density which received 12 and 18mg/kg showed decreased monogeneoidea values, seven days after the experiment begin. Six, 12 and 18 mg/kg caused reduction in the dinoflagellate number in the fishes maintained at 20kg/m³. It was possible that chromium supplementation (12 e 18mg/kg favoured the fishes health by reducing Monogenoidea and Dinoflagellida number in lower and higher densities, respectively.O objetivo do trabalho foi avaliar a intensidade de parasitismo por monogenóide Anacanthorus penilabiatus e pelo dinoflagelado Piscinoodinium pillulare em pacus Piaractus mesopotamicus, cuja dieta foi suplementada com cromo. Foram utilizados dois delineamentos em esquema fatorial, consistindo de 4 níveis de cromo (0, 6, 12, 18 mgCQC/kg, duas densidades de estocagem (4 kg/m³ e 20 kg/m³ e duas classes de tamanho para monogenóide (maiores e menores de 17cm e/ou 3 períodos de coleta (7, 60 e 90 dias, com quatro repetições. Os peixes que receberam 12 e 18mg CQC/kg apresentaram diminuição de monogenóides após 7 dias de alimentação na menor densidade. Nos peixes na maior densidade, os níveis de 6, 12 e 18 mgCQC/kg ocasionou redução de dinoflagelados. Os resultados demonstraram que a suplementação com cromo (12 e 18 mgCQC/kg promoveu uma melhora na saúde dos peixes na menor e na maior densidade, respectivamente.

Sobre la ecología de Brycon siebenthalae y Mylossoma duriventris (Piscis: Characidae, en el río Cafre, Orinoquia

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Useche L. Carlos

1993-12-01

Full Text Available The ecology of the characids Bryeon siebenthalaey Mylossoma duriventriswas studied in the lower part of the río Cafre, a tributary of was studied the río Guayabero in the upper part of the río Guaviare system in Colombia. These lishes spawn in the early rainy season; theír diet consist mainly 01 Iruits, seeds, flowers and bark.En este trabajo se reportan nuevos aspectos sobre la biología de Bryeon siebenthalae (yamú y de Mylossoma duriventris (palometa. La reproducción de especies está altamente relacionada con la estacionalidad hídrica (lluvias-sequías la palometa desova tan pronto comienzan las lluvias a finales de abril, con un promedio de 125.000 huevos; el yamú desova aproximadamente 231.000 huevos, dos a tres semanas más tarde, mediados de mayo. El alto número de huevos implica que el desove debe efectuarse en niveles de aguas que faciliten su dispersión. Las dos especies comparten los hábitat (cursos del río, planos inundables. Es característico del yamú su mayor desplazamiento al remontar grandes corrientes y raudales, en el desarrollo de su comportamiento migratorio de tipo longitudinal, a diferencia de la palometa cuyos movimientos son preleriblemente de tipo local y lateral a la corriente. En ambas especies predomina un hábito alimenticio macroherbívoro, correspondiente a frutos, semillas, hojas. flores y cortezas: para el yamú en un 93% y para la palometa en 99%.

Two new species of Hyphessobrycon (Teleostei: Characidae from upper rio Tapajós basin on Chapada dos Parecis, central Brazil

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Tiago Pinto Carvalho

Full Text Available Two new species of Hyphessobrycon are described from the upper rio Tapajós basin, Mato Grosso, Brazil. Hyphessobrycon melanostichos is distinguished from its congeners by the combination of a conspicuous longitudinal broad black band beginning on the posterior margin of orbit and reaching the tip of middle caudal fin rays, a distinct vertically elongate humeral spot, and 16 to 18 branched anal-fin rays. Hyphessobrycon notidanos is distinguished from its congeners by the combination of an elongate dorsal fin in mature males, a vertically elongate humeral spot, 2-4 maxillary teeth, iii,8 dorsal-fin rays, and 16 to 21 branched anal-fin rays.

Diet-morphology relationship in the stream-dwelling characid Deuterodon stigmaturus (Gomes, 1947 (Characiformes: Characidae is partially conditioned by ontogenetic development

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Renato Bolson Dala-Corte

Full Text Available ABSTRACT We tested whether interindividual variations in diet composition within a population of Deuterodon stigmaturus can be explained by morphological differences between individuals, and whether diet-morphology relationships are dependent on the ontogenetic development. We analyzed diet of 75 specimens sampled in a coastal stream of Southern Brazil. Variation in stomach content was summarized with a Principal Coordinate Analysis (PCoA. The retained PCoA axes were tested as response to standard length (SL, and to values of intestine length (IL and mouth length (ML independent of body size, using linear mixed-effects models (LMM. The most consumed food items by D. stigmaturus were filamentous algae (41%, terrestrial plants (20.3%, detritus (12%, and aquatic invertebrates (8.8%. The LMMs showed that SL was positively related to consumption of terrestrial plants, whereas IL independent of SL was negatively related to aquatic invertebrates and positively related to filamentous algae. When body sized was held constant, ML was not related to diet variation. Interindividual diet differences conditioned to body size suggest that individuals shift their trophic niche and function in the ecosystem along the ontogenetic development. Relationships between intestine length and diet composition suggest interindividual differences in foraging ability and digestibility of distinct food items.

Morphometric variation between two morphotypes within the Astyanax Baird and Girard, 1854 (Actinopterygii: Characidae) genus, from a Mexican tropical lake.

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Ornelas-García, Claudia P; Bastir, Markus; Doadrio, Ignacio

2014-07-01

Phenotypic variation is important for evolutionary processes because it can allow local adaptation, promote genetic segregation, and ultimately give rise to speciation. Lacustrine systems provide a unique opportunity to study the mechanisms by which sister species can co-occur by means of ecological segregation. The fish genus Astyanax is characterized by high levels of phenotypic variability, providing an excellent model for the study of local specialization. Here, we analyze the morphological specializations through geometric morphometrics of two sympatric species described as different genera: Bramocharax caballeroi endemic to Lake Catemaco, and the widely distributed Astyanax aeneus. Additionally, we assess the correlation between phenotypic and genetic structure, and the phylogenetic signal of morphological variation. We examined body size and shape variation in 196 individuals and analyzed mitochondrial cytochrome b sequences in 298 individuals. Our results confirm the striking morphological divergence among the sympatric characids. Differences between them were mainly found in the body depth and profile and orientation of the head, where B. caballeroi in contrast with the A. aeneus, presented a fusiform body and an upward mouth. Moreover, different growth trajectories were observed among morphotypes, suggesting that a heterochronic process could be involved in the diversification of our study system. Morphological differences did not correspond with the molecular differentiation, suggesting high levels of homoplasy among the lineages of B. caballeroi morphs. © 2014 Wiley Periodicals, Inc.

Feeding dynamics and ecomorphology of Oligosarcus jenynsii (Gunther, 1864) and Oligosarcus robustus (Menezes, 1969) in the Lagoa Fortaleza, southern Brazil.

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Nunes, D M; Hartz, S M

2006-02-01

Oligosarcus jenynsii and Oligosarcus robustus are fishes of Characidae family that occur in Rio Grande do Sul, Uruguay and northern Argentina. This work purported to study the feeding dynamics (repletion and hepatosomatic indexes and condition factor) over time, and to investigate the coexistence of these two species by evaluating the partition of resources using qualitative and quantitative analyses of diet, temporal and spatial segregation throughout the water column and some ecomorphological aspects of the species in the Lagoa Fortaleza. Specimens were sampled monthly, from May 2000 to April 2001 during 24 h/month, using stationary gill nets of different mesh sizes. The records of each individual included total and standard length; total, stomach and liver weight; sex and stomach repletion. The variation of the mean values of repletion index and relative frequencies of stomach repletion stages indicate that O. jenynsii and O. robustus do not present seasonal differences in feeding intensity. The hepatosomatic index shows an allocation of energy to the liver during every period except reproduction, when part of the energy is used for gonad maturation. The estimated condition factor for both species reveals an increase in the reproductive period, evidencing the influence of gonads upon the condition of the fish. The diet analysis revealed that O. robustus is piscivorous, whereas O. jenynsii is a generalist carnivore, tending to piscivory as well. The active period of O. robustus is more concentrated at sunrise and sunset, whereas O. jenynsii is continually active, a characteristic related to hunting for prey. The ecomorphological analysis revealed differences between the two species in the dimensions of the mouth. Evidence suggests that the species coexist, sharing food sources, differing in oral morphology but ingesting similar prey, possibly because food is not a limiting factor in the environment.

Lake size and fish diversity in southern Brazil coastal lagoons

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Lucia Ribeiro Rodrigues

2015-10-01

Full Text Available The coastal plain of Rio Grande do Sul, southern Brazil, presents a series of shallow lagoons with diverse size and morphology. The objective of this study is to determine whether the size of the lagoon is an effective factor for structuring fish diversity. In this regard, nine lagoons with distinct areas were sampled: three with an area up to 40 hectares, three with area between 40 and 80 hectares, and three with an area of over 80 hectares. Each lagoon was sampled once on the littoral and pelagic zones. At each point, fish were captured through a set of gill nets with different mesh sizes. Captured specimens were identified, quantified and evaluated for weight and length. A total of 24 fish species belonging to 10 families was obtained, with Characidae presenting the highest species richness. Cyanocharax alburnus was the only species that occurred in all lagoons. Cyphocharax voga, Astyanax eigenmmaniorum, Oligosarcus jenynsii and O. robustus were also frequent species, present in most of the sampled lagoons. Lycengraulis grossidens was captured in just two lagoons with increased conductivity. The community structure showed the highest species richness in lakes with an area over 40 ha, however the highest mean diversity values were observed in ponds up to 40 ha. Cluster Analysis yielded the formation of two groups: a group formed by just one lagoon and a second one cluster grouping all the other lagoons. This pattern may be associated with the presence of Lycengraulis grossidens as a dominant species in this lagoon clustered apart. The results indicate that lagoons with up to 40 ha present greater homogeneity on the species composition and higher average values of diversity; while intermediate ponds (between 40 and 80 ha have lower average diversity for the fish fauna due to increased heterogeneity in species abundance.

Evaluación de la tasa de consumo de oxígeno de Colossoma macropomum en relación al peso corporal y temperatura del agua

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Dennis Tomalá

2014-11-01

Full Text Available Colossoma macropomum es una especie de la región amazónica perteneciente a la familia Characidae, la de mayor diversidad de peces de agua dulce. A nivel de laboratorio, se determinó la tasa de consumo de oxígeno (CO en metabolismo de rutina de C. macropomum a diferentes pesos corporales: 40, 60, 90, 140 y 250 g (expresados por unidad de masa corporal y temperatura del agua de 21, 26 y 31°C. El experimento se diseñó completamente al azar en arreglo factorial (5x3x3, utilizando un respirómetro de 20 L y una bomba de recirculación de agua. Las mediciones del CO fueron realizadas cada 5 min mediante el uso de un oxímetro digital. Los resultados indican que el CO mantiene relación directa con la temperatura del agua e inversa con el peso corporal de los organismos (P < 0,05. Las regresiones entre las variables independientes y el CO se ajustaron a ecuaciones potenciales: CO = 2844,9 P-0,734, CO = 2555,9 P-0,624 y CO = 1945,4 P-0,507 a 21, 26 y 31°C respectivamente; donde P se expresa en kg, obteniéndose altos coeficientes de correlación y determinación. La ecuación resultante del análisis multivariado de regresión lineal múltiple fue: CO = 4,839 - (0,708* P + (9,106* T. Los resultados ofrecen información para estimar la capacidad de un ambiente acuícola en base a la demanda de oxígeno de C. macropomum, aportando al desarrollo de una acuicultura con mayor sustento técnico.

Feeding dynamics and ecomorphology of Oligosarcus jenynsii (Gunther, 1864 and Oligosarcus robustus (Menezes, 1969 in the Lagoa Fortaleza, southern Brazil

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D. M. Nunes

Full Text Available Oligosarcus jenynsii and Oligosarcus robustus are fishes of Characidae family that occur in Rio Grande do Sul, Uruguay and northern Argentina. This work purported to study the feeding dynamics (repletion and hepatosomatic indexes and condition factor over time, and to investigate the coexistence of these two species by evaluating the partition of resources using qualitative and quantitative analyses of diet, temporal and spatial segregation throughout the water column and some ecomorphological aspects of the species in the Lagoa Fortaleza. Specimens were sampled monthly, from May 2000 to April 2001 during 24 h/month, using stationary gill nets of different mesh sizes. The records of each individual included total and standard length; total, stomach and liver weight; sex and stomach repletion. The variation of the mean values of repletion index and relative frequencies of stomach repletion stages indicate that O. jenynsii and O. robustus do not present seasonal differences in feeding intensity. The hepatosomatic index shows an allocation of energy to the liver during every period except reproduction, when part of the energy is used for gonad maturation. The estimated condition factor for both species reveals an increase in the reproductive period, evidencing the influence of gonads upon the condition of the fish. The diet analysis revealed that O. robustus is piscivorous, whereas O. jenynsii is a generalist carnivore, tending to piscivory as well. The active period of O. robustus is more concentrated at sunrise and sunset, whereas O. jenynsii is continually active, a characteristic related to hunting for prey. The ecomorphological analysis revealed differences between the two species in the dimensions of the mouth. Evidence suggests that the species coexist, sharing food sources, differing in oral morphology but ingesting similar prey, possibly because food is not a limiting factor in the environment.

Variações espaciais na assembléia de peixes no Rio Paraíba do Sul (Barra Mansa, Barra do Piraí, Rio de Janeiro, Brasil Spatial variation in fish assemblage in the Paraíba do Sul River (Barra Mansa, Barra do Piraí, Rio de Janeiro, Brazil

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Francisco Gerson Araújo

2001-06-01

Full Text Available The Paraíba do Sul is a major running water system in southeastern Brazil (22º24' -22º26'S; 43º43' -44º16' W, draining one of the most important industrial regions in the country. Because of its location, it has suffered a large amount of alteration due to discharges of urban and industrial effluents with direct influence in the ichthyofauna. The aim of this study is to up-to-date information on fish assemblage structure and its variation in the vicinity of a major industrial effluent outfall at Volta Redonda industrial complex. A standardized fishing sampling program, using seines, casting nets, gill nets and net trays, was carried out from October 1997 to September 1999, at six sites in three zones of the river (upstream, nearby and downstream the industrial complex, aiming to compare variation in fish assemblage due to anthropogenic alteration. Fifty-two species in 13 families were identified in the total of 7286 fish specimens. Characidae was the most diverse family contributing with 28,85% to total number of species, followed by Cichlidae (17,31 %. Overall 15,38% of the species were introduced from other watershed systems, four exotic cichlids (genera Oreochromis Günther, 1862 and Tilapia A. Smith, 1840 and three aloctone (Cichla ocellaris Bloch & Schneider, 1801, Hyphessobricon callistus (Boulenger, 1900 e Metynnis maculatus (Kner, 1860. Lebistes reticulatus (Peters, 1859 was the most abundant fish species contributing to 39,7% of the total number of fish, followed by Geophagus brasiliensis (Quoy & Gaimard, 1824 amounting to 27,4%. Fish abundance was higher in the industrial zone, but only a few very dominant species were captured, while the upstream zone showed the most even community. Species replacement tolerance along the alterations gradient in the three zone seems to be a strategy to use the limited resources in the area.

Influência da primeira alimentação na larvicultura e alevinagem do yamú Brycon siebenthalae (Characidae - DOI: 10.4025/actascianimsci.v25i1.2092 First feeding influence on yamú, Brycon siebenthalae (Characidae larval rearing - DOI: 10.4025/actascianimsci.v25i1.2092

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Sandra Pardo-Carrasco

2003-04-01

Full Text Available Para avaliar a influência da primeira alimentação na alevinagem do yamú, Brycon siebenthalae, no Instituto de Acuicultura/Universidad de Los Llanos (Villavicencio, Colômbia, foram desenvolvidos dois experimentos. No experimento 1, testaram-se, durante vinte e quatro horas, diferentes tipos de alimento vivo como primeira alimentação das pós-larvas (PL de yamú: náuplios de Artemia sp. (NA, zooplâncton silvestre (ZS e larvas de pirapitinga (LP (Piaractus brachypomus. No tratamento controle as pós-larvas foram mantidas em jejum. O alimento que proporcionou melhores resultados em ganho de peso e comprimento total foi larvas de pirapitinga (p Two experiments were carried out at Instituto de Acuicultura de Los Llanos/Universidad de Los Llanos (Villavicencio, Colômbia to evaluate first feeding influence on yamú larval rearing. In the first experiment, the following prey types were tested to first feeding for yamú larvae during 24 hours: Artemia sp. nauplii, wild zooplankton and pirapitinga (Piaractus brachypomus larvae. In the control yamú larvae were subjected to starvation. Pirapitinga larva was the prey item that offered the best results for weight and total length gain (p < 0.05. In the second experiment, yamú larvae performance was compared when stocked into fertilized ponds during 15 days either at the onset feeding or after first feeding with pirapitinga larvae prey item. Survival rate was lower in the larvae that were stocked into rearing ponds at the onset of feeding (13.4% when compared to survival of yamú larvae that were stocked after receiving pirapitinga larvae (74.1%. These results indicate that the use of pirapitinga larvae at first feeding increases performance of yamú larval rearing.

Praziquantel, levamisol e diflubenzuron no controle de Dolops carvalhoi (Crustacea: Branchiura e Anacanthorus penilabiatus (Monogenea: Dactylogyridae em Piaractus mesopotamicus Holmberg, 1887 (Osteichthyes: Characidae Praziquantel, levamisole and diflubenzuron in the control of Dolops carvalhoi (Crustacea: Branchiura and Anacanthorus penilabiatus (Monogenea: Dactylogyridae in Piaractus mesopotamicus Holmberg, 1887 (Osteichthyes: Characidae

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Sergio Henrique Canello Schalch

2009-03-01

Full Text Available Neste trabalho, avaliou-se a eficácia antiparasitária do praziquantel, levamisol e diflubenzuron administrados via oral, adicionados à ração, para pacus (Piaractus mesopotamicus infectados por Anacanthorus penilabiatus e Dolops carvalhoi. Foram utilizadas 19 caixas d'água de 300 L de capacidade, comportando 28 peixes cada. Os tratamentos foram feitos misturando os princípios ativos nas dietas. A intensidade parasitária e eficácia foram avaliadas 1 dia antes e 3, 7 e 15 dias após o início da alimentação com ração contendo diflubenzuron, levamisol e praziquantel isolados ou associados em diferentes concentrações por 7 dias. Os resultados da eficácia terapêutica sugerem que, isoladamente ou associado com levamisol e praziquantel, o diflubenzuron é eficiente contra o crustáceo D. carvalhoi, demonstrando que a eficácia dos tratamentos nos dias 3, 7 e 15 variou de 96,2 a 100%. Contra os monogenóides, as drogas não apresentaram eficácia satisfatória. Os resultados sugerem o uso do diflubenzuron para o controle de D. cavalhoi em peixes de cativeiro e em condições de quarentenário.This assay evaluated the control efficacy of diflubenzuron, praziquantel and levamisole added to the diet of pacu (Piaractus mesoptamicus infected with Anacanthorus penilabiatus and Dolops carvalhoi. 19 water tanks of 300 L capacity were utilized with 28 fish in each one. The treatments were made by mixing the active principles in the diet. The experiment was evaluated in four harvests done 1 day before and 3, 7 and 15 days after the treatment. The medicated feeding was applied for 7 days. The results of efficacy suggest that the diflubenzuron alone or associated with levamisole and praziquantel was efficient against the crustacean D. carvalhoi and the efficacy in the 3, 7 and 15 days evaluations ranged from 96,2 to 100%. Against the monogenean the drugs did not present efficacy. The results suggest the use of diflubenzuron for the control of D. carvalhoi in captive fishes in special conditions.

Biologia reprodutiva e reprodução induzida de duas espécies de Characidae (Osteichthyes, Characiformes da bacia do São Francisco, Minas Gerais, Brasil Reproductive biology and induced breeding of two Characidae species (Osteichthyes, Characiformes from the São Francisco River basin, Minas Gerais, Brazil

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Yoshimi Sato

2006-03-01

Full Text Available Astyanax bimaculatus (Linnaeus, 1758 e Tetragonopterus chalceus Spix & Agassiz, 1829 são duas importantes espécies de peixes forrageiros da bacia do São Francisco. Espécimes destas duas espécies foram submetidos à indução da desova através de hipofisação, para observação de aspectos reprodutivos e obtenção de subsídios para definição de protocolo de reprodução artificial. Machos e fêmeas receberam dose única de extrato bruto de hipófise de carpa comum (6 mg/kg de peixe. A extrusão de ovócitos foi realizada cerca de 12,8 e 11 h após a aplicação da injeção de hipófise, respectivamente para A. bimaculatus e T. chalceus, com a temperatura da água a 26ºC. Mais de 70% das fêmeas das duas espécies responderam positivamente ao tratamento e as taxas médias de fertilização dos ovos foram acima de 70%. Os ovócitos de A. bimaculatus e T. chalceus são esféricos, opacos, demersais, levemente adesivos, de coloração amarela ou parda, e contendo em média respectivamente 4774 e 2563 ovos por grama de ova. O desenvolvimento embrionário nas duas espécies foi rápido, com duração de menos de um dia, estando a temperatura da água entre 24 e 25ºC.Astyanax bimaculatus (Linnaeus, 1758 and Tetragonopterus chalceus Spix & Agassiz, 1829 are two important foraging species occurring at the São Francisco River basin. Specimens from both species were submitted to spawning induction through hypophysation, to study some reproductive features and to obtain subsidiary information for the definition of the artificial reproduction protocol. Males and females were treated with a single dose of crude carp pituitary extract (6 mg/kg. In water at 26ºC, the extrusion of the oocytes was made 12,8 and 11 hours after the hypophisis injection, for A. bimaculatus and T. chalceus respectively. More than 70% of the females of both species showed a positive response to the treatment and mean egg fertilization rates were above 70%. The eggs of A. bimaculatus and T. chalceus are yellow or medium brown, spherical, opaque, demersal, and slightly adhesive. The ova contained 4774 and 2563 eggs (mean values per gram respectively. The embryonic development in both species was fast, lasting less than a day when water temperature was between 24 and 25ºC.

Evaluation of the haematological parameters in Piaractus mesopotamicus Holmberg (Osteichthyes, Characidae with Argulus sp. (Crustacea, Branchiura infestation and treatment with organophosphate

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Marcos Tavares-Dias

1999-06-01

Full Text Available Haematological parameters as erythrocytes, leukocytes and plasma glucose in Piaractus mesopotamicus Holmberg, 1887 were analyzed. Fish were parasitized with Argulus sp. (Crustacea, Branchiura and treated with 0.4 mg of thriclorphon 500/L water. The effects of parasitism and the action of the treatment were evaluated. Parasitized fish showed greater number of monocytes (P>0.05 and special granulocitic cells (P0.05. Organophosphate treatment presented significantly reduction (P>0.05 in red blood cells (RBC and hemoglobin.

Ontogenic changes in the feeding habits of the fishes Agonostomus monticola (Mugilidae and Brycon behreae (Characidae, Térraba River, Costa Rica

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Thiago Cotta-Ribeiro

2009-11-01

Full Text Available Las dietas de los peces varían con respecto a la calidad, la cantidad y el tamaño del alimento. Esta variación puede deberse a factores como la estacionalidad y la fase del desarrollo del individuo. Estudiamos los cambios ontogénicos en los hábitos alimentarios de dos peces dulceacuícolas, Agonostomus monticola y Brycon behreae, de la Cuenca del Río Térraba, Pacífico sur de Costa Rica. Ambas poblaciones son omnívoras, pero con cambios ontogénicos en la cantidad y calidad de los ítemes consumidos. Conforme crecía, A. monticola modificó su dieta de insectívora hacia un mayor consumo de materia vegetal, asociado con un aumento en la longitud relativa del intestino. Aunque mantuvo su dependencia de alimentos vegetales, B. behreae diversificó su dieta de dos formas. Primero, pasó de partes suaves de plantas a semillas, hojas y frutos. Luego, los ítemes cambiaron de insectos hacia una dieta más carnívora (peces y camarones. Estos hallazgos para ambas especies enfatizan la importancia de proteger la vegetación riparia de estos ecosistemas tropicales.Fish diets can vary in food quality, quantity and size. The variation can be caused by several factors, including season and the ontogenic phase of the individual (McCormick 1998. We studied the ontogenic changes in feeding habits of two freshwater fishes, Agonostomus monticola and Brycon behreae, from the Térraba River basin, South Pacific of Costa Rica. Both populations were omnivorous, but displayed ontogenic shifts in terms of quantity and quality of the food items consumed. As it grew, A. monticola modified its diet from insectivorous towards a higher consumption of vegetables, which was accompanied by an increase in relative length of the intestine. While remaining dependent on vegetation as staple food, B. behreae diversified its diet in two ways. Initially, from soft plant parts to seeds, leaves, and fruits. Secondly, prey items changed from insects into a more carnivore diet (fish and shrimp. These findings for both species stress the importance of protecting riparian vegetation in these tropical ecosystems. Rev. Biol. Trop. 57 (Suppl. 1: 285-290. Epub 2009 November 30.

Ontogenic changes in the feeding habits of the fishes Agonostomus monticola (Mugilidae and Brycon behreae (Characidae, Térraba River, Costa Rica

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Thiago Cotta-Ribeiro

2009-11-01

Full Text Available Las dietas de los peces varían con respecto a la calidad, la cantidad y el tamaño del alimento. Esta variación puede deberse a factores como la estacionalidad y la fase del desarrollo del individuo. Estudiamos los cambios ontogénicos en los hábitos alimentarios de dos peces dulceacuícolas, Agonostomus monticola y Brycon behreae, de la Cuenca del Río Térraba, Pacífico sur de Costa Rica. Ambas poblaciones son omnívoras, pero con cambios ontogénicos en la cantidad y calidad de los ítemes consumidos. Conforme crecía, A. monticola modificó su dieta de insectívora hacia un mayor consumo de materia vegetal, asociado con un aumento en la longitud relativa del intestino. Aunque mantuvo su dependencia de alimentos vegetales, B. behreae diversificó su dieta de dos formas. Primero, pasó de partes suaves de plantas a semillas, hojas y frutos. Luego, los ítemes cambiaron de insectos hacia una dieta más carnívora (peces y camarones. Estos hallazgos para ambas especies enfatizan la importancia de proteger la vegetación riparia de estos ecosistemas tropicales.

Temporal distribution and early development of Moenkausia cf. gracilima (Lucena & Soares, 2016 (Osteichthyes, Characidae in the upper Paraná River, Brazil

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Joyce Andreia dos Santos

2017-12-01

Full Text Available Abstract Aim: To analyze temporal distribution of larvae and juveniles and the early development and of Moenkhausia cf. gracilima. Methods Samples were taken quarterly in twenty-five sites in the upper Paraná River floodplain between August 2013 and May 2015. The samples were taken under the water surface at night using 0.5 mm mesh plankton nets. In the laboratory, samples were sorted, identified and separated into larval (preflexion, flexion and postflexion and juvenile periods. Results A total of 248 individuals was collected, mainly in the Saraiva Lagoon, suggesting that the entire life cycle of this species occurs in this environment. The reproductive period takes place between December and April, since the postflexion larvae were found until May. However, the occurrence of juveniles between February and May indicates probable batch spawning. Among the 95 individuals used for ontogenic description, 82 were larvae and 13 juveniles. Larvae may be characterized by irregular pigmentation in the upper region of the head, mouth, and body, increasing throughout development; upper lobe of the caudal fin more pigmented than the lower lobe, only visible in postflexion larvae; terminal mouth; anal opening located anterior to the median region of the body and total number of myomers ranging from 34 to 40 (15 to 20 pre and 16 to 23 postanal, while juveniles have characteristics similar to adults. The total number of fin rays is: P. 11-16, V. 7-11, D, 9-11 and A. 21-23. Conclusions According to the distribution of developmental periods it is possible to conclude that this species reproduces in the summer, preferably in lagoons. Growth analysis indicated important alterations in larval morphology (metamorphosis that may be associated with the ecomorphological characteristics of the species. The morphological separation of larvae of M. cf. gracilima from other larvae of small characids, especially at preflexion and flexion stages may be complicated by the overlap of traits, suggesting the use of other variables, mainly morphometric, for the separation of the species.

The occurence of black spot disease in Astyanax aff. fasciatus(characiformes: characidae in the Guaíba Lake basin, RS, Brazil

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F Flores-Lopes

Full Text Available Black spot disease is common in freshwater fish and is usually caused by the metacercaria stage of digenetic trematodes, normally from the Diplostomidae family. The present study evaluated the prevalence and intensity of this disease in Astyanax aff. fasciatus(Teleostei: Characiformes in the Guaíba Lake basin (RS, Brazil, including body parts assessment and the points of sampling with higher occurrence of black spots. Fish samples were taken seasonally from December 2002 until October 2004. The samples were collected with the use of a seine net at eleven points. The specimens were fixed in 10% formalin and stored in 70% ethanol. Black spot disease showed a low frequency in the Guaíba lake basin (2.07% and no specificity to the species Astyanax aff. fasciatus was observed. A high prevalence among the individuals and high intensity of infection levels was found in the ventral and dorsal regions in relation to other body parts (e.g., pectoral, pelvic and anal regions. Among the sampling points studied, we observed a higher prevalence on samples collected at points Gasômetro, Saco da Alemoa and Sinos, located in open areas with less occurrence of mollusks.

Host-parasite interactions between the piranha Pygocentrus nattereri (Characiformes: Characidae and isopods and branchiurans (Crustacea in the rio Araguaia basin, Brazil

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Lucélia Nobre Carvalho

Full Text Available In the tropics, studies on the ecology of host-parasite interactions are incipient and generally related to taxonomic aspects. The main objective of the present work was to analyze ecological aspects and identify the metazoan fauna of ectoparasites that infest the piranha, Pygocentrus nattereri. In May 2002, field samples were collected in the rio Araguaia basin, State of Goiás (Brazil. A total of 252 individuals of P. nattereri were caught with fishhooks and 32.14% were infested with ectoparasite crustaceans. The recorded ectoparasites were branchiurans, Argulus sp. and Dolops carvalhoi and the isopods Braga patagonica, Anphira branchialis and Asotana sp. The prevalence and mean intensity of branchiurans (16.6% and 1.5, respectively and isopods (15.5% and 1.0, respectively were similar. Isopods were observed in the gills of the host; branchiurans were more frequent where the skin was thinner, and facilitated attachment and feeding. The ventral area, the base of the pectoral fin and the gular area were the most infested areas. The correlations between the standard length of the host and the variables intensity and prevalence of crustaceans parasitism, were significant only for branchiurans (rs = 0.2397, p = 0.0001; chi2 = 7.97; C = 0.19. These results suggest that both feeding sites and body size probably play an important role in the distribution and abundance of ectoparasites.

Biomonitoramento de metais pesados no Córrego do Cravo e Represa Paraíso utilizando Astianax bimaculatus (Linnaeus, 1758 (Characiformes, Characidae

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Samuel Mariano-da-Silva

2012-06-01

Full Text Available As áreas utilizadas como lixões e aterros controlados são focos potenciais de poluição, uma vez que os resíduos sólidos podem conter substâncias químicas com características tóxicas, como os metais pesados por exemplo. Este trabalho teve como objetivo avaliar os teores de cobalto, cádmio, chumbo, cromo, cobre, ferro, manganês e zinco em chorume e em peixes da espécie Astyanax bimaculatus oriundos do córrego do Cravo e da Represa Paraíso, que sofre com a contaminação direta e indireta dos líquidos percolados do aterro controlado de Jataí – GO. Uma amostra de chorume foi extraída da bacia de deposição, situada no lado nordeste do aterro. Outras onze amostras foram coletadas em diferentes pontos de afloramento superficial espontâneo, todos estes localizados sobre o aterro sanitário, totalizando doze amostras de chorume. Os espécimes foram coletados entre os meses de janeiro a março de 2008, utilizando anzol, em toda a extensão (5 km, em 32 pontos do Córrego do Cravo (±130 em 130 metros e em 3 pontos da Represa Paraíso. Foi comprovada a contaminação pelos metais cádmio, chumbo, cromo e ferro, considerando os valores máximos permitidos, indicando que nos compartimentos ambientais estudados está havendo contaminação.

Spatial, seasonal and ontogenetic variation in the diet of Astyanax aff. fasciatus (Ostariophysi: Characidae in an Atlantic Forest river, Southern Brazil

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Luciano Lazzarini Wolff

Full Text Available This study described the feeding habits of the characin Astyanax aff. fasciatus. The diet compositions of specimens from two sites (A and B on a river in Southern Brazil were compared according to the size of individuals and seasonal period. The collections were performed monthly from March 2005 to February 2006, where the stomach contents of 290 specimens were assessed. Food items for A. aff. fasciatus were basically composed of plants and insects, especially leaf fragments, seeds, fruits, filamentous algae, aquatic and terrestrial insects and insect fragments. At site A, the most common items were insect and plant fragments. Conversely at site B, plant fragments were more representative. In general, all items of animal origin showed the highest feeding index values at site A, whereas at site B detritus and grass items were more abundant. The composition of items varied seasonally, with higher diversity of items being recorded during the spring at both sites. Smaller individuals preferred items of animal origin, while the larger ones consumed mainly items of plant origin. According to its size, A. aff. fasciatus in this study may be considered a species with insectivorous tendencies when immature or herbivorous tendencies when adult. Nevertheless, its feeding habits may be flexible according to resource availability, showing wide ontogenetic, besides spatial and temporal variation.

Changes in the fish community of the Kpong Headpond, lower Volta River, Ghana after 25 years of impoundment

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Theodore Quarcoopome

2011-12-01

Full Text Available The Kpong Headpond was the second created on the Volta River after Akosombo Dam, primarily as a source of hydroelectric power generation and potable water supply, and additionally, it has supported some fish production in Ghana since impoundment. The changes in fish community of the Kpong Headpond were studied to provide baseline information for strategies formulation to support the socio-economic development of the reservoir. The study identified changes in the fish community of the reservoir by comparing occurrence, composition, relative abundance and relative importance estimates of fish species, families and trophic groups, from available previous studies in the reservoir. From the collated information all fishes identified in the reservoir were categorised based on occurrence and importance as disappeared, appeared, permanent, declined or important, to show current status. The results indicated that the fish community has experienced a shift in the composition and relative abundance of important species, families and trophic groups in terms of number and weight, while remaining ecologically balanced. Representatives of the families Osteoglossidae, Centropomidae and Characidae have declined while representatives of the families Claroteidae, Cyprinidae and Cichlidae have increased. The aufwuch-detritus and herbivores declined while semi-pelagic omnivores increased resulting in a shift in dominance to benthic and semi pelagic omnivores. The appearance of five species and the disappearance of 25 others indicated a dynamic restructuring of the fish community in the reservoir, as expected. Enforcement of fishing regulations including the use of appropriate gear and fishing methods, fishery access control, promotion of culture-based fisheries and improvement in fisher education are recommended topics for sustainable fisheries in the reservoir. Rev. Biol. Trop. 59 (4: 1685-1696. Epub 2011 December 01.La laguna Kpong se convirtió en la segunda

Fish mercury development in relation to abiotic characteristics and carbon sources in a six-year-old, Brazilian reservoir

Energy Technology Data Exchange (ETDEWEB)

Tuomola, Leena; Niklasson, Terese [Evolutionary Biology Centre and Department of Limnology, Uppsala University, Norbyvaegen 20, S-752 36 Uppsala (Sweden); Castro e Silva, Edinaldo de [Departamento de Quimica, Universidade Federal de Mato Grosso (UFMT), Av. Fernando C. Costa/sn, 78 090-900 Cuiaba-MT (Brazil); Hylander, Lars D. [Department of Earth Sciences, Air, Water and Landscape Science, Uppsala University, Villavaegen 16, S-752 36 Uppsala (Sweden)], E-mail: Lars.Hylander@hyd.uu.se

2008-02-01

Time series on fish mercury (Hg) development are rare for hydroelectric reservoirs in the tropics. In the central-western part of Brazil, a hydroelectric reservoir, called Lago Manso, was completed in 1999 after that background levels of fish Hg concentrations had been determined. The development for the first 3 years was studied in 2002. The objective of the present study was to determine development of fish Hg concentrations for a second three-year period after flooding. The bioaccumulation factor and certain abiotic and biotic factors, possibly affecting the availability and accumulation of Hg, were also examined. The results show that Hg levels in fish from Lago Manso have increased more than five times compared to the background levels observed before construction of the reservoir. At the same time, dissolved organic carbon has increased while dissolved oxygen has decreased indicating enhanced bioavailability of Hg. In the reservoir, Salminus brasiliensis had in average a Hg content of 1.1 {mu}g g{sup -1} f.w., Pseudoplatystoma fasciatum 1.2, Serrasalmus marginatus/spilopleura 0.9, and Brycon hilarii 0.6 {mu}g g{sup -1} f.w. The average fish Hg contents were higher downstream, except for B. hilarii. In the reservoir, the average Hg content of each species was in 2005 always over the consumption limit (0.55 {mu}g total Hg g{sup -1} f.w.) recommended by WHO. Therefore, the people living around Lago Manso should be informed of the health effects of Hg, and fish consumption recommendations should be carried out. The accumulation of Hg varies widely between species as shown by the bioaccumulation factor which ranges between 5.08 and 5.59 log units. The observed variation is explained by differences in diet and trophic position with piscivorous fish exhibiting the highest mean Hg concentration, followed by carnivorous and omnivorous species. Carbon isotope analyses imply that trophic position is not the only cause of the observed differences in Hg levels between

A new species of Philometra Costa, 1845 (Nematoda: Philometridae) from the freshwater fish (red piranha) Pygocentrus nattereri Kner (Characidae) in Amazonia, Brazil

Czech Academy of Sciences Publication Activity Database

Cárdenas, M. Q.; Moravec, František; Fernandes, B. M. M.; Morais, A. M.

2012-01-01

Roč. 83, č. 2 (2012), s. 137-144 ISSN 0165-5752 R&D Projects: GA ČR GBP505/12/G112 Institutional research plan: CEZ:AV0Z60220518 Keywords : Philometra * Pygocentrus * Brazil Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.260, year: 2012 http://link.springer.com/article/10.1007%2Fs11230-012-9377-4

Influence of spawning procedure on gametes fertilization success in Salminus hilarii Valenciennes, 1850 (Teleostei: Characidae: Implications for the conservation of this species

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Renato M. Honji

2011-06-01

Full Text Available Artificial reproduction and gamete fertilization were evaluated in Salminus hilarii wild and domesticated broodstocks. Wild and domesticated broodstocks were artificially induced to reproduction using a carp pituitary treatment. Four groups were considered: Group 1 (G1, fish caught in the wild maintained for three years in the same conditions as the domesticated broodstocks and spawned naturally; Group 2 (G2, broodstock born and raised in captivity and spawned naturally; Group 3 (G3, wild broodstocks, which were manually stripped for gamete collection and dry fertilization; and Group 4 (G4, domesticated males and females, also manually stripped. Oocytes, eggs, and larvae were sampled at different time intervals throughout embryonic development. Yolk sac absorption occurred approximately 24-29 h after hatching. Twenty-six h after hatching, the larvae mouths opened. Cannibalism was identified just 28-30 h after hatching. There was no morphological difference in embryonic development among all groups. The number of released eggs per gram of female was: G1: 83.3 ± 24.5 and G2: 103.8 ± 37.4; however, the fertilization success was lower in G2 (42.0 ± 6.37 % compared with G1 (54.7 ± 3.02% (P = 0.011. Hand-stripping of oocytes was not successful and the fertilization rate was zero. The reproduction of this species in captivity is viable, but it is necessary to improve broodstock management to enhance fertilization rates and obtain better fingerling production for restocking programs.A reprodução artificial e fertilização dos gametas foram avaliados em reprodutores selvagens e de cativeiro de Salminus hilarii. Reprodutores selvagens e de cativeiro foram induzidos artificialmente à reprodução utilizando hipófise de carpa. Quatros grupos foram considerados: Grupo 1 (G1, peixes capturados na natureza, mantidos por três anos nas mesmas condições de reprodutores de cativeiro e desovados naturalmente; Grupo 2 (G2, reprodutores nascidos e criados em cativeiro e desovados naturalmente; Grupo 3 (G3, reprodutores selvagens que foram extrusados manualmente para a coleta de gametas e fertilização a seco; e Grupo 4 (G4, com machos e fêmeas domesticadas, também extrusados manualmente. Oócitos, ovos e larvas foram amostrados em diferentes intervalos de tempo ao longo do desenvolvimento embrionário. A absorção do saco vitelínico ocorreu aproximadamente 24-29 h após a eclosão. Vinte e seis h após a eclosão, as larvas abriram a boca. O canibalismo foi identificado apenas 28-30 h após a eclosão. Não houve diferença morfológica no desenvolvimento embrionário entre todos os grupos. O número de ovos liberados por grama de fêmea foi: G1: 83,3 ± 24,5 e G2: 103,8 ± 37,4; embora, o sucesso na fertilização tenha sido menor no G2 (42,0 ± 6,37% em comparação com G1 (54,7 ± 3,02% (P = 0,011. A extrusão manual dos oócitos não foi bem sucedida e a taxa de fertilização foi zero. A reprodução em cativeiro desta espécie é viável, mas é necessário um melhor manejo dos reprodutores para aumentar as taxas de fertilização, visando a obtenção de uma melhor produção de alevinos para os programas de repovoamento.

Influence of spawning procedure on gametes fertilization success in Salminus hilarii Valenciennes, 1850 (Teleostei: Characidae: Implications for the conservation of this species

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Renato M. Honji

Full Text Available Artificial reproduction and gamete fertilization were evaluated in Salminus hilarii wild and domesticated broodstocks. Wild and domesticated broodstocks were artificially induced to reproduction using a carp pituitary treatment. Four groups were considered: Group 1 (G1, fish caught in the wild maintained for three years in the same conditions as the domesticated broodstocks and spawned naturally; Group 2 (G2, broodstock born and raised in captivity and spawned naturally; Group 3 (G3, wild broodstocks, which were manually stripped for gamete collection and dry fertilization; and Group 4 (G4, domesticated males and females, also manually stripped. Oocytes, eggs, and larvae were sampled at different time intervals throughout embryonic development. Yolk sac absorption occurred approximately 24-29 h after hatching. Twenty-six h after hatching, the larvae mouths opened. Cannibalism was identified just 28-30 h after hatching. There was no morphological difference in embryonic development among all groups. The number of released eggs per gram of female was: G1: 83.3 ± 24.5 and G2: 103.8 ± 37.4; however, the fertilization success was lower in G2 (42.0 ± 6.37 % compared with G1 (54.7 ± 3.02% (P = 0.011. Hand-stripping of oocytes was not successful and the fertilization rate was zero. The reproduction of this species in captivity is viable, but it is necessary to improve broodstock management to enhance fertilization rates and obtain better fingerling production for restocking programs.

Population structure and reproduction of Deuterodon langei travassos, 1957 (Teleostei, Characidae in a neotropical stream basin from the Atlantic Forest, Southern Brazil

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Jean Ricardo Simões Vitule

2008-12-01

Full Text Available Aspects of the biology of D. langei were studied at different sites along a longitudinal gradient formed by the Ribeirão stream basin, a Neotropical stream of the Atlantic Forest, southern Brazil. Differences were observed in population structure and reproduction along the longitudinal gradient and during the study period. Juvenile fishes occurred in high abundance, mainly in the downstream site after the rainy months. Adults occurred mainly in the intermediate and upstream sites. During their life cycle, adults optimise their reproductive strategy by concentrating the reproductive period with total spawn in a short time interval before summer rains dragged the juvenile, larval forms and/or eggs downstream. The downstream site was characterized by a wide range of microhabitats (ex. submerged grass and shallow flooded area. Thus, the species used different portions of the basin in distinct stages of its life, being ecologically adapted to variation patterns in its temporal and physical environments.Aspectos da biologia de D. langei foram estudados em diferentes locais da bacia do rio Ribeirão, um riacho litorâneo da Floresta Atlântica do sudeste do Brasil. Foram observadas diferenças na estrutura da população e na reprodução, ao longo do gradiente longitudinal da bacia e do período de estudo. Os peixes juvenis ocorreram em grande abundância, principalmente no trecho a jusante da bacia, após os meses mais chuvosos. Adultos ocorreram principalmente nos trechos intermediários e a montante. Não houve diferença significativa na relação sexual entre os locais amostrados, estações do ano, meses e classes de comprimento. O comprimento médio de primeira maturação (L50 foi o mesmo para machos e fêmeas, entre 6,1 e 7,0 cm de comprimento total (Lt. O período reprodutivo foi curto (entre o final da primavera e início do verão, antes dos meses mais chuvosos, com desova total. O Índice de Atividade Reprodutiva (IAR indicou que D. langei reproduz em toda a bacia, porém a atividade reprodutiva é mais intensa nos trechos mais a montante da bacia. O período chuvoso e as chuvas torrenciais se mostraram fatores abióticos muito importantes para a dinâmica da população. Durante seu ciclo de vida os adultos maximizam sua estratégia reprodutiva concentrando o período reprodutivo, com desova total em um curto espaço de tempo antes das chuvas de verão que carregam juvenis, formas larvais e/ou ovos para as regiões a jusante onde existe uma ampla quantidade de micro-ambientes (gramíneas submersas e áreas rasas e calmas. Desta forma a espécie estudada utilizou diferentes porções da bacia em distintos estágios de seu ciclo de vida, demonstrando estar ecologicamente adaptada às variações temporais e físicas do ambiente.

Knodus shinahota (Characiformes: Characidae a new species from the río Shinahota, río Chapare basin (Mamoré system, Bolivia

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Katiane M. Ferreira

Full Text Available Knodus shinahota, new species, is described from río Shinahota, a tributary of the upper rio Mamoré basin, Província de Tiraque, Cochabamba State, Bolivia. The new species can be distinguished from all congeners except K. chapadae and K. geryi by having six rows of scales between the lateral line and the dorsal-fin origin (vs 4 or 5 rows of scales in the other species. Knodus shinahota differs from K. chapadae by possessing more rows of scales between the lateral line and the pelvic-fin origin (5 vs 3½ or 4, respectively and more lateral line scales (38-41 vs 36-38, respectively. It differs from K. geryi by possessing more rows of scales between the lateral-line and the pelvic-fin origin (5 vs 4, respectively; fewer branched anal-fin rays (17-20 vs 15-17, respectively, and by lacking the two symmetric, large, dark, blotches on the basal portions of the caudal-fin lobes that characterize K. geryi.

A new Hasemania Ellis from the upper rio Paraná basin, with the redescription of Hasemania crenuchoides Zarske & Géry (Characiformes: Characidae

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Jane Piton Serra

Full Text Available A new Hasemania species is described from the headwaters of the rio Uberaba, rio Grande basin, State of Minas Gerais, Brazil. The new species is distinguished from its congeners by a combination of a black, vertically-elongate humeral spot, a single ossification in the position primitively occupied by infraorbitals four and five, four teeth on the inner series of premaxilla, and scales covering the anal-fin base. Hasemania crenuchoides is redescribed and its known geographic distribution is extended; it can be differentiated from other species of the genus by the combination of a black vertically-elongate humeral spot, ii,8 dorsal-fin rays, 11-14 branched anal-fin rays, the presence of separate infraorbitals four and five, and the presence of scales covering the anal-fin base. Phylogenetic relationships of H. crenuchoides and the new species within Hasemania are discussed.

ANÁLISIS FILOGENÉTICO Y BIOGEOGRÁFICO DE LAS ESPECIES DEL GÉNERO BRYCONAMERICUS (CHARACIFORMES, CHARACIDAE DE LA BAJA AMÉRICA CENTRAL

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Román Cesar

2009-12-01

Full Text Available Se presenta una hipótesis preliminar de monofi lia para las especies de Bryconamericusde la baja América Central, basada en caracteres moleculares de ADNmt, que resultaen el siguiente arreglo de relaciones fi logenéticas: (B. emperador (B. gonzalezoi(B. bayano, (B. terrabensis, B. scleroparius. Esta hipótesis es preliminar en elcontexto fi logenético del género, sin embargo, aumenta la probabilidad de que estegrupo se constituya en un grupo natural. Se halla concordancia entre la hipótesisde relaciones presentada para las especies de Bryconamericus analizadas aquí y loshallazgos con base en caracteres morfológicos. A través de biogeografi a cladística,cladogramas de áreas, cladogramas resueltos de áreas y Análisis de Dispersión-Vicarianza (DIVA se comprueba que la hipótesis biogeográfi ca para las especiesde Bryconamericus está relacionada con un proceso de dispersión desde el noroestede América del Sur, que permitió colonizar la baja Centroamérica. Simultáneamenteocurrieron extinciones, y como producto de la reorganización geológica y aislamientogeográfi co de las poblaciones, aparece la vicarianza.

Feeding and social behavior of the piabanha, Brycon devillei (Castelnau, 1855 (Characidae: Bryconinae in the wild, with a note on following behavior

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Pedro G Azevedo

Full Text Available Knowledge concerning the behavior of wild freshwater fishes in Brazil is restricted to a few studies, despite such studies being able to answer fundamental questions about conservation. Species of Brycon are amongst the most threatened in the Neotropics, particularly in southeast Brazil, due to anthropogenic activities in this region. This study investigated the feeding and social behaviors of the endangered fish, Brycon devillei in the Preto River, Jequitinhonha basin, Minas Gerais State, Brazil. Behavioral data were collected by snorkeling with four spatially separated groups (habituated, and direct observations of shoals were made using an underwater video camera (a total of 448 hours of observations. This species showed diverse tactics to obtain food. However, the species proved to be predominately a specialist surface-picker, which adopted alternative tactics to find food at certain times of the year, most notably when food items on the water surface became low. Feeding frequency was shown to be negatively correlated to agonistic behavior between conspecifics. Feeding associations were also recorded between the anostomid Leporinus garmani, acting as a nuclear species, and B. devillei, as follower species. The data presented here showed the importance of conserving the riparian environment to protect B. devillei populations. Furthermore, the present study included rare observations of nuclear-follower feeding association among freshwater fishes, especially between medium-sized characiforms, being the first observations of such kind in a Cerrado stream.

Variación morfológica de los peces Hemibrycon boquiae y Hemibrycon rafaelense (Characiformes: Characidae en el Río Cauca, Colombia

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César Román-Valencia

2009-09-01

Full Text Available Analizamos la variación morfológica y osteológica en Hemibrycon boquiae y H. rafaelense en la cuenca del río Cauca. Los análisis multivariados determinan poblaciones de H. boquiae en las quebradas: Boquiae, Honda, Las Águilas, Doña Juana, Villa Paola, Portachuelo, La Víbora, Aimes y Ramírez y poblaciones de H. rafaelense en las quebradas: Canceles, La Clara, San Rafael y San José. No hay diferencias en la morfometría entre las poblaciones de H. boquiae y H. rafaelense. Se presentan discrepancias merísticas significativas para las poblaciones de H. boquiae (n= 277 y H. rafaelense (n= 121 en: número de escamas entre la línea lateral y la aleta anal, y número de escamas entre la línea lateral y la aleta pélvica. La distancia de similaridad del análisis de agrupamiento ("cluster" para los caracteres osteológicos, al igual que el número de escamas predorsales, apoyan la existencia de dos grupos discretos que corresponden a H. boquiae y H. rafaelense.Morphological variation in populations of Hemibrycon boquiae and H. rafaelense from Rio Cauca, Colombia. We analyzed the variation in morphological and osteological characteristics of Hemibrycon boquiae and Hemibrycon rafaelense in the Cauca River. The multivariate analysis determined populations of H. boquiae in nine streams: Boquier, Honda, Las Aguilas, Doña Juana, Villa Paola, Portachuelo, The Snake, Aimes and Ramirez, and populations of H. rafaelense in four streams: Canceles, Clara, San Rafael and San Jose. There were morphometric differences among populations of H. boquiae (n= 277 and H. rafaelense (n= 121. Nevertheless, there were significant meristic discrepancies among populations of both species: number of scales between lateral line and anal fin, and number of scales between lateral line and pelvic fin. The absence of bilateral symmetry was observed in the number of maxillary teeth in H. boquiae. The cluster analysis distance for osteological characters, including the number of predorsal scales, separated H. boquiae and H. rafaelense in two defined groups. Rev. Biol. Trop. 57 (3: 541-556. Epub 2009 September 30.

Fish assemblage in a semi-arid Neotropical reservoir: composition, structure and patterns of diversity and abundance.

Science.gov (United States)

Novaes, J L C; Moreira, S I L; Freire, C E C; Sousa, M M O; Costa, R S

2014-05-01

The aim of this study was to analyse the composition, structure and spatial and temporal patterns of diversity and abundance of the ichthyofauna of the Santa Cruz Reservoir in semi-arid Brazil. Data were collected quarterly at eight sampling locations on the reservoir between February 2010 and November 2011 using gillnets from 12- to 70-mm mesh that were left in the water for 12h00min during the night. We evaluated the composition, structure and assemblage descriptors (Shannon-Wiener diversity index and equitability, respectively) and catch per unit effort by the number (CPUEn) and biomass (CPUEb) of the ichthyofauna. The 6,047 individuals (399,211.6 g) captured represented three orders, ten families and 20 species, of which four belonged to introduced species. The family Characidae was the most abundant with a total of 2,772 (45.8%) individuals captured. The species-abundance curve fit the log-normal model. In the spatial analysis of diversity, there were significant differences between sampling sites in the lacustrine and fluvial regions, and the highest values were found in the lacustrine region. In the temporal analysis of diversity, significant differences were also observed between the rainy and dry seasons, and the higher values were found during the dry season. Equitability followed the same spatiotemporal pattern as diversity. The Spearman correlation was significantly negative between diversity and rainfall. A cluster analysis spatially separated the ichthyofauna into two groups: one group formed by sampling sites in the fluvial region and another group formed by the remainder of the points in the lacustrine region. Both the CPUEn and CPUEb values were higher at point 8 (fluvial region) and during the rainy season. A two-way ANOVA showed that the CPUEn and CPUEb values were spatially and temporally significant. We conclude that the spatial and temporal trends of diversity in the Santa Cruz reservoir differ from those of other Brazilian reservoirs but that

The Canal da Piracema at Itaipu Dam as a fish pass system

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Sérgio Makrakis

Full Text Available The Canal da Piracema is the longest (nearly 10 km fish pass system in the world. The construction of this fish pass was somehow controversial, because it connected two distinct ichthyofaunistic provinces. This study evaluated the ichthyofauna present in the Canal da Piracema and the abundance and distribution of long-distance migratory fish species along this fish pass system (evaluated possible selectivity. The Canal da Piracema was shown to be difficult to sample because of its environmental heterogeneity: artificial ponds, ladders and nature-like fish pass. To solve this problem, we used several fishing gears, adequate for the several biotopes present (unstructured and structured littoral were sampled with seining nets and electrofishing; lentic were sampled with gillnets and longlines (deeper areas; and rapid water areas were sampled with cast nets. The ichthyofauna of the Canal da Piracema followed the pattern for South America and the Paraná River, with a predominance of Characiformes and Siluriformes. The most representative families were Characidae, Anostomidae, Pimelodidae and Loricariidae. We captured 116 species (17 were long-distance migratory during the period studied. Small-sized species were predominant in unstructured and structured littoral areas, especially Bryconamericus exodon and Apareiodon affinis.The most abundant species was Hypostomus spp. in lentic areas, followed by Iheringichthys labrosus. Hoplias aff. malabaricus predominated in deeper lentic areas. Long-distance migratory species were abundant in rapid waters; they were Prochilodus lineatus and Leporinus elongatus. The sharp reduction in the number of species, including migratory ones, is an indication that the Canal da Piracema is selecting the species that ascend it. Therefore, the search for information on the efficiency of the various fish passes present in the Canal da Piracema is fundamental, to facilitate upward movements of fish. If this is reached, this

Composição e estrutura da comunidade de peixes de um afluente do rio Tietê, bacia do Alto rio Paraná.

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Jane Piton Serra

2014-09-01

Full Text Available A América do Sul contém a mais rica e variada ictiofauna de água doce do mundo, porém, muito dessa diversidade ainda é desconhecida, tanto na sua composição, quanto em aspectos ecológicos, biológicos e taxonômicos. Essa riqueza, entretanto tem sido afetada pelas alterações antrópicas dos ambientes naturais. Assim, o objetivo do presente trabalho foi determinar a composição e estrutura da ictiofauna do ribeirão Borá, afluente do rio Cubatão, drenagem do rio Tietê, bacia do alto rio Paraná. O local estudado foi um trecho de quinta ordem e aproximadamente 80 m de extensão do ribeirão, localizado no município de Nova Aliança, São Paulo. O ribeirão Borá apresenta características de ambiente antropizado, como pouca vegetação marginal e pontos poucos profundos com sedimento predominantemente arenoso. Foram realizadas 10 coletadas diurnas entre Novembro de 2002 e Março de 2004. O tempo de coleta e os equipamentos utilizados foram padronizados. Foram coletadas 41 espécies de peixes, pertencentes a 15 famílias e cinco ordens, totalizando 1.459 exemplares. A ordem Characiformes apresentou maior riqueza, seguida por Siluriformes. A família Characidae foi a mais rica, seguida por Loricariidae e Cichlidae. Os maiores valores para riqueza e abundância foram encontrados na estação chuvosa. Os resultados obtidos neste trabalho constituem uma forma importante de conhecimento da ictiofauna e reforçam a importância de estudos sobre a composição e estrutura das comunidades de peixes, tanto em ambientes ainda não modificados, quanto naqueles com intenso processo de degradação, como subsídio para conservação e recuperação dos ambientes aquáticos.

Comparative study on hematological parameters of farmed matrinxã, Brycon amazonicus Spix and Agassiz, 1829 (Characidae: Bryconinae with others Bryconinae species Estudo comparativo sobre parâmetros hematológicos de matrinxã Brycon amazonicus Spix e Agassiz, 1892(Characidae: Bryconinae criados em cativeiro, com outras espécies de Bryconinae

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Marcos Tavares-Dias

2008-12-01

Full Text Available The aim of this study was not only to determine the red blood cells parameters, thrombocyte and leukocyte counts in farmed Brycon amazonicus (matrinxã, to compare these parameters among Bryconinae species from literature, and also to investigate the presence of special granulocytic cells in these fish. The results of the blood cells parameters here established for farmed B. amazonicus, a species of great economic importance in Brazilian aquaculture, could help a better understanding of the blood features in natural populations of this Amazon species. Blood parameters varied between Bryconinae species investigated, mainly the red blood cell counts, hemoglobin, hematocrit and mean corpuscular volume (MCV. The presence of the blood granulocytes, neutrophils and heterophils in matrinxã suggest that both leukocytes can be a characteristic for Bryconinae family. Furthermore, it indicates that the existence of special granulocytic cells in the blood of Bryconinae species from literature is an artifact, and this was herein discussed.O objetivo deste estudo foi determinar os parâmetros eritrocíticos, as contagens de trombócitos e de leucócitos de espécimes de Brycon amazonicus (matrinxã, criados em cativeiro e compará-los com aqueles descritos na literatura para outras espécies de Bryconinae. Além disso, foi ainda investigada a presença de células granulocíticas especiais nestes peixes. Os resultados dos parâmetros sangüíneos apresentados para B. amazonicus podem ajudar a entender melhor as características sangüíneas em população natural desta espécie de grande importância para a aqüicultura brasileira. Os parâmetros sangüíneos das espécies de Bryconinae investigadas apresentaram variação interespecíficas principalmente a contagem de eritrócitos, hemoglobina, hematócrito e volume corpuscular médio (VCM. A presença dos granulócitos sangüíneos, neutrófilos e heterófilos em matrinxã sugere que esta pode ser uma característica das espécies pertencentes à subfamília Bryconinae. Além disso, indica que a existência de células granulocíticas especiais no sangue de espécies de Bryconinae da literatura é um artefato, e isto foi aqui discutido.

Morfologia do trato digestório e dieta de larvas de Bryconamericus aff. iheringii (Boulenger, 1887 (Osteichthyes, Characidae - DOI: 10.4025/actascibiolsci.v28i1.1059 Morphology of Digestive tract and diet of Bryconamericus aff. iheringii larvae (Boulenger, 1887 (Osteichthyes, Characidae - DOI: 10.4025/actascibiolsci.v28i1.1059

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Keshiyu Nakatani

2006-03-01

Full Text Available Este trabalho teve como objetivo analisar alguns aspectos da alimentação de larvas de Bryconamericus aff. iheringii, capturadas nos meses de julho e novembro de 2001, nas regiões limnética e litorânea do reservatório de Santa Maria, rio Piquiri, Estado do Paraná. As larvas apresentaram boca subterminal durante todo o seu desenvolvimento. O tubo digestório se diferenciou em estômago e intestino apenas no estágio de pós-flexão. As larvas consumiram, principalmente, algas e microcrustáceos, o que permitiu caracterizá-las como planctófagas. A intensa modificação morfológica no trato digestório nos indivíduos em pós-flexão coincidiu com o aumento na abundância de algas em relação aos itens de origem animal; porém, de forma geral, a ocorrência aumentou para todos os itens. A análise do grau de digestão dos itens alimentares sugeriu que indivíduos em pré-flexão alimentaram-se, possivelmente, durante o dia, e os mais desenvolvidos, durante o entardecer e no período noturnoThe aim of this study was to analyze some feeding treats of Bryconamericus aff. iheringii larvae, sampled in both the limnetic and littoral regions of the Piquiri River, in Santa Maria reservoir, between July and November 2001. The larvae presented sub-terminal mouth in larval period. The digestive tract differentiated in terms of stomach and intestine only in the postflexion larvae. The larvae fed mainly on algae and microcrustacea allowing to characterize them as planktivorous. The intense morphologic shift in the digestive tract in the postflexion larvae coincided with an increase in the abundance of algae in relation to animals items; however, in general, all the items had their occurrence increased. Analysis of the digestion stage suggested that preflexion larvae, possibly, fed themselves during the day, and those more developed, at dusk and night

Influência de diferentes níveis de vitamina C na ração sobre parâmetros hematológicos de alevinos de Piaractus mesopotamicus Holmberg (Osteichthyes, Characidae Influence of different levels of vitamin C in the ration on the haematological parameters of Piaractus mesopotamicus Holmberg (Osteichthyes, Characidae fries

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Maurício Laterça Martins

1995-09-01

Full Text Available Haematological changes in ascorbic acid deficient fishes, observed by some authors, awoked the interest in the haematological response of pacu, Piaractus mesopotamicus. The present work studied the influence of different levels of ascorbic acid (vitamin C in the ration on the haematological parameters of pacu. Fishes at the beginning of the experiment, presented average body weight 8.64±1.62g and 6.15±0.33cm standard length, were fed with diets containing 0. 50, 100 and 200mg ascorbic acid/kg dry ration. The present work was developed for a period of 24 weeks at the Fish Nutrition Laboratory of Aquaculture Center of Universidade Estadual Paulista (Unesp, Jaboticabal (São Paulo. The fishes were distributed by the completely randomized design in 20 aquaria of 100 liters capacity with six animals in each and five fold treatment. Condutivity, alcalinity. pH and oxigen were measured weekly and temperature daily. The blood colect was done in 60 anesthetized fishes with 50mg MS-222/1. The results suggests that 50mg ascorbic acid/kg dry ration improved the mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration and decreased haematocril in unsupplemented fishes, although not differing significantly (P>0.05. The erytrocyte diameter indicated the presence of macrocytic cells in unsupplemented fishes (P<0.05 and the regression analysis showed too reduced neutrophils in unsupplemenled ones, 50mg ascorbic acid/kg dry ration supplementation was enough to development and haematological responses. Furthtermore, the optimum level to the growth is 139mg vitamin C/kg dry ration (P<0.05.

A new species of Hemigrammus Gill, 1858 (Characiformes: Characidae from the rio Madeira and rio Paraguai basins, with a redescription of H. lunatus

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Rafaela P. Ota

Full Text Available A new Hemigrammusis described from the rio Paraguai and rio Madeira basins, Mato Grosso and Rondônia States, Brazil. The new species is characterized by possessing a wide dark horizontal stripe across the eye, a vertically elongated humeral blotch, and 4-5 gill-rakers on upper branch and 9-10 on lower. The new species can be easily diagnosed from H. lunatus, the sympatric and morphologically most similar congener, by the shape of humeral blotch and the number of gill rakers. Data of the type material of both Hemigrammus lunatus and H. maxillaris, as well as extensive examination of specimens, allowed us to conclude that H. maxillarisis a junior subjective synonym of H. lunatus. A redescription of H. lunatus, as well as a formal restriction of its type locality, is provided. A putative monophyletic group within Hemigrammus, composed by H. barrigonae, Hemigrammus lunatus, H. machadoi new species, and H. ulreyi, named Hemigrammus lunatus group, is proposed based on overall body morphology and color pattern. Additionally, a discussion on the biogeographical relationships between the rio Paraguai and rio Guaporé basins is provided.

Ecología trófica de la Sabaleta Brycon henni (Pisces: Characidae en el río Portugal de Piedras, Alto Cauca, Colombia

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Alvaro Botero-Botero

2011-04-01

Full Text Available Objetivo. Estudiar la ecología trófica de la sabaleta (Brycon henni en el río Portugal de Piedras, cordillera Oriental, departamento del Valle del Cauca. Materiales y métodos. Desde octubre de 2008 hasta junio de 2009 se realizaron pescas exploratorias y se determinaron parámetros físico y químicos del hábitat. Los ejemplares capturados fueron eviscerados y el contenido estomacal fue determinado hasta el mínimo taxón posible. Resultados. La especie presenta una dieta generalista que incluye 35 categorías alimenticias, con tendencia al consumo de larvas y ninfas de insectos acuáticos entre los cuales se destacan tricópteros, dípteros y odonatos; también, consume organismos alóctonos al cauce como hormigas (Hymenoptera, escarabajos (Coleoptera y material vegetal: frutos, semillas y hojas. La relación longitud intestino (LI vs. longitud estándar (LS indican que la especie presenta características propias de una especie carnívora (LI = -13.8728 + 1.02377*LS, r= 0.35, n= 22, a su vez, el peso total (PT depende directamente de la longitud total (LT y LS del pez (PT = -49.308 + 0.609962*LT; r= 0.92 n=30; PT = -41.6011 + 0.672529*LS; r= 0.89, n=30, respectivamente. Conclusiones. La sabaleta (Brycon henni presentó caracteristicas de una especie carnivora.

Lophiobrycon weitzmani, a new genus and species of glandulocaudine fish (Characiformes: Characidae from the rio Grande drainage, upper rio Paraná system, southeastern Brazil

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Ricardo M. C. Castro

Full Text Available A new genus and species of glandulocaudine, Lophiobrycon weitzmani, is described based on specimens collected in headwater tributary streams of the rio Grande, upper rio Paraná system, State of Minas Gerais, southeastern Brazil. The inclusion of the new species in the phylogeny of the subfamily Glandulocaudinae proposed by Weitzman & Menezes (1998, reveals a sister group relationship between the new genus and the monophyletic group composed of Glandulocauda and Mimagoniates that currently form the tribe Glandulocaudini. The new species can be readily distinguished from all other species of the tribe by the autapomorphic presence in adult male individuals (with more than 23.9 mm standard length of an adipose-fin whose base extends for almost the entire distance between the posterior terminus of the base of the dorsal fin and the base of the upper lobe of the caudal fin and averages approximately 25% standard length, along with the presence of globular expansions formed by the lepidotrichia and hypertrophied soft tissue in the middle portions of the first and second pectoral-fin rays. The diagnosis of the tribe Glandulocaudini is modified to accommodate the new genus.

Hematologia de teleósteos brasileiros com infecção parasitária. I. Variáveis do Leporinus macrocephalus Garavelo e Britski, 1988 (Anostomidae e Piaractus mesopotamicus Holmberg, 1887 (Characidae Haematology of parasitized Brazilian teleost fishes. I. Parameters of Leporinus macrocephalus Garavelo and Britski, 1988 (Anostomidae and Piaractus mesopotamicus Holmberg, 1887 (Characidae

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Dilermando Perecin

1999-07-01

Full Text Available Espécimes de Leporinus macrocephalus (piauçu e de Piaractus mesopotamicus (pacu foram colhidos em piscicultura do município de Franca (SP para avaliação dos efeitos da infecção parasitária sobre a taxa de hemoglobina e de hematócrito, a concentração de hemoglobina corpuscular média (CHCM, o fator relativo de condição (Kn e a distribuição percentual de células sangüíneas de defesa orgânica (leucócitos e trombócitos. Ambas as espécies apresentavam-se parasitadas por monogenea ou por monogenea e outros parasitas: monogenea e Trichodina sp; monogenea e Lernaea cyprinacea; monogenea e Piscinoodinium pillulare; monogenea e Ichthyophthirius multifiliis; monogenea, I. multifiliis e Trichodina sp. Os resultados demonstraram que os parâmetros estudados em L. macrocephalus e em P. mesopotamicus não foram significativamente (p > 0,05 alterados pelo parasitismo. A análise de regressão linear mostrou correlação negativa (p > 0,05 entre linfócitos e trombócitos em L. macrocephalus e correlação positiva (p > 0,01 da taxa de hemoglobina com o peso e com o comprimento total em P. mesopotamicus.Specimens of cultivated Leporinus macrocephalus (piauçu and Piaractus mesopotamicus (pacu were collected in a fishfarm at Franca, SP. Effects of parasite infection upon hemoglobin, hematocrit, mean corpuscular hemoglobin concentration (MCHC, condition factor (Kn and differential count of defense cells (leucocyte and thrombocyte were evaluated. Both fish species were parasitized by monogenean; monogenean and Trichodina sp; monogenean and Lernaea cyprinacea; monogenean and Piscinoodinium pillulare; monogenean and Ichthyophthirius miltifiliis; monogenean, I. multifiliis and Trichodina sp. Parasitism did not influence (p > 0.05 the studied haematological characteristics in L. macrocephalus and P. mesopotamicus. Linnear regression showed negative correlation (p > 0.05 between lymphocytes and thrombocytes in L. macrocephalus and positive correlation (p > 0.01 of the hemoglobin rate with fish weight and fish length in P. mesopotamicus.

Reproducción y dinámica poblacional de Cheirodon interruptus (Ostariophysi: Characidae en el arroyo El Portugués, alta cuenca del río Samborombón, Argentina Reproduction and population dynamics of Cheirodon interruptus (Ostariophysi: Characidae in El Portugués, a stream in the upper watershed of the Samborombon River, Argentina

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Ricardo A Ferriz

2011-01-01

Full Text Available Se determinó el período reproductivo de Cheirodon interruptus mediante el análisis de 1.658 especímenes capturados mensualmente en el arroyo El Portugués, Argentina, desde mayo 2004 hasta abril 2005. En base a los estadios de madurez y del índice gonodosomático (IGS de las hembras se determinaron dos etapas de desove, una en primavera y otra en otoño. Se encontró una correlación significativa entre el IGS medio mensual de los machos con la profundidad. El IGS de las hembras presentó una correlación significativa con el fotoperíodo y la profundidad. El resto de las variables ambientales, incluyendo temperatura, pH, conductividad y precipitación mensual, no mostró una correlación con la media mensual del IGS. La primera madurez sexual en hembras y machos se observó en la clase 24-26 mm de longitud estándar. La fecundidad absoluta media fue de 448 ovocitos (DE = 217,8 y la fecundidad relativa media fue de 0,33 (DE = 0,097 ovocitos por miligramo de peso corporal, siendo un desovante del tipo parcelado. El diámetro de los ovocitos varió entre 0,05 y 0,70 mm, con una media de 0,48 mm (DE = 0,16.The reproductive period of Cheirodon interruptus was determined by analyzing 1658 individuals collected monthly in the stream El Portugués, Argentina, from May 2004 to April 2005. Two prolonged spawning seasons, one in spring and another in autumn, were observed based on the maturity stages and gonadosomatic índex (GSI of female specimens. The mean monthly GSI of males was significantly correlated with depth. In females, the GSI exhibited a significant correlation with photoperiod and depth. The remaining environmental variables, including temperature, pH, conductivity, and monthly rainfall, did not show a correlation with the mean monthly GSI. The first sexual maturity in females and males was reached within the 24-26 mm standard length class. The mean absolute fecundity was 448 oocytes (SD = 217.8, and the mean relative fecundity was 0.33 (SD = 0.097 oocytes per milligram of body weight; this species is a múltiple spawner. The oocyte diameter ranged from 0.05 to 0.70 mm, with a mean of 0.48 mm (SD = 0.16.

Chrysobrycon eliasi, new species of stevardiine fish (Characiformes: Characidae from the río Madre de Dios and upper río Manuripe basins, Peru

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James Anyelo Vanegas-Ríos

Full Text Available Chrysobrycon eliasi is described from several drainages of río Madre de Dios and upper río Manuripe basins, río Madeira basin, Peru. The new species is distinguished from its congeners by the maxillary teeth, which are tricuspidate, bicuspidate and conical, and the terminal lateral-line tube developed between caudal-fin rays 10-11. Other characters that help to recognize C. eliasi are the possession of maxilla with 6-15 (usually 11 teeth occupying more than 70% of the length of the maxilla in adults, predorsal scales 18-22, dorsal-fin to hypural complex length 36.32-41.17% of standard length (SL, gill-gland length in males 3.57-5.05% SL, maxillary length 33.76-38.75% of head length, and branched anal-fin rays 24-30. The discovery of C. eliasi allows us to extend the geographic distribution of the genus to the southeast, into the río Madeira basin.

Auriculostoma astyanace n. gen., n. sp. (Digenea: Allocreadiidae), from the banded astyanax, Astyanax fasciatus (Characiformes: Characidae), from Nicaragua, with a reevaluation of neotropical Crepidostomum spp

Czech Academy of Sciences Publication Activity Database

Scholz, Tomáš; Aguirre-Macedo, M. L.; Choudhury, A.

2004-01-01

Roč. 90, č. 5 (2004), s. 1128-1132 ISSN 0022-3395 R&D Projects: GA AV ČR IAA6022404 Institutional research plan: CEZ:AV0Z6022909 Keywords : Digenea * Allocraediidae * Auriculostoma Subject RIV: EG - Zoology Impact factor: 1.439, year: 2004

Variações ecomorfológicas e de uso de habitat em Piabina argentea (Characiformes, Characidae da bacia do Rio das Velhas, Minas Gerais, Brasil

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Cecília G. Leal

2013-09-01

Full Text Available O presente estudo teve como objetivo investigar os padrões local e regional de uso de habitat de Piabina argentea Reinhardt, 1867 em quatro diferentes rios da bacia do rio das Velhas. Os habitat amostrados foram caracterizados quanto à velocidade da água, profundidade e tipo de substrato. Para a análise ecomorfológica, foram calculados 17 atributos ecomorfológicos de 40 exemplares de cada rio. Embora estas populações tenham se sobreposto no espaço ecomorfológico, a Análise Discriminante Canônica mostrou haver diferença significativa entre elas, principalmente da população do rio das Velhas em relação às demais. A separação se deu em termos do índice de compressão, altura relativa do corpo e índice de achatamento ventral. Os padrões locais de seleção de habitat não foram congruentes em todos os rios, mas em geral, houve predomínio do padrão regional: habitat lênticos, profundidade entre 20 e 40 cm e 60 e 80 cm e substrato areia, silte+argila e banco de folhas. Considerando as características físicas de cada rio e o padrão regional da espécie, a maior parte dos seus requerimentos de habitat é contemplada nos quatro rios. Entretanto, um corpo d'água assoreado como o trecho do rio das Velhas, tende a ter maiores velocidades da água, menores profundidades e substrato finos, o que atende em parte à seleção de habitat da espécie estudada.

Efecto de diferentes niveles de proteína de la dieta sobre el crecimiento de juveniles del pez neón Paracheirodon innesi (pisces:characidae

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Jorge Luna-Figueroa

2016-03-01

Full Text Available Se evaluó el efecto de alimentos con diferente concentración de proteína (53,5%, 50,0%, 41,6% y 30,0% sobre las tasas de crecimiento absoluto (TCA, relativo (TCR y específico (TCE de juveniles de P. innesi. El incremento en peso y en longitud total, así como las tasas de crecimiento fueron mayores en los peces alimentados con la dieta I (53,5% proteína y decrecieron conforme disminuyó la concentración de proteínas en el alimento (P<0,05. Las diferencias porcentuales promedio referentes al peso fueron 65,15% TCA, 63,69% TCR y 45,85% TEC, mientras que para la longitud total fueron 57,41% TCA, 59,00% TCR y 52,25% TCE mayores (P<0,05 en los peces alimentados con la dieta I respecto de la II, III y IV. Finalmente, los resultados de la presente investigación indican que el nivel de proteína de la dieta que produce máximo crecimiento en P. innesi es 53,5%.

Estrutura morfológica do fígado de tambaqui Colossoma macropomum (Cuvier, 1818

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Gerlane de Medeiros Costa

2012-09-01

Full Text Available Este trabalho teve como objetivo descrever macro e microscopicamente o fígado do Tambaqui Colossoma macropomum, Teleósteo de água doce da Família Characidae, de grande interesse econômico da bacia Amazônica. Foram utilizados seis (6 exemplares jovens com idade entre seis meses e um ano, oriundos da Chácara Esteio, Alta Floresta, MT, que desenvolve principalmente a prática da piscicultura. O órgão foi fotodocumentado in situ e descrito macroscopicamente, em seguida procedeu-se a retirada de fragmentos deste, que foram processados pelas técnicas histológicas rotineiras para inclusão em parafina e coloração de HE. O fígado localizou-se ventral à bexiga natatória e craniodorsalmente ao estômago, apresentou coloração amarronzada a vermelho, constituído por três lobos hepáticos, o lobo lateral direito, o lobo lateral esquerdo e o lobo ventral. Microscopicamente, o parênquima era constituído por hepatócitos com formato que variou do arredondado irregular hexagonal ao redondo com núcleo grande e central, arranjados em cordões lineares limitados por sinusóides que irradiam para veias centrais, e com ausência de lóbulos hepáticos. As veias centrais estavam distribuídas pelo parênquima, enquanto que o espaço porta, na maioria das vezes, era constituído apenas por uma veia hepática e o ducto biliar, em outros locais foi observado, uma artéria e um ducto. Não foi observada a formação de tríades portais. Foram frequentemente observados melano macrófagos centrais dispersos pelo parênquima. O estudo morfofuncional do Aparelho Digestório de peixes da bacia Amazônica, se faz pertinente com vistas ao conhecimento do aproveitamento de ganho de peso e produção em alta escala para consumo humano e preservação da espécie, além da importância de estarem sendo utilizados como bioindicadores atualmente.

The fish fauna of Anambra river basin, Nigeria: species abundance and morphometry

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Gregory Ejikeme Odo

2009-06-01

Full Text Available The fish yields of most Nigeria inland waters are generally on the decline for causes that may range from inadequate management of the fisheries to degradation of the water bodies. Sustainable exploitation requires knowledge of the ichthyofaunal composition in the water bodies. We did a survey of fish species in Anambra river basin for 22 months. Fish samples were collected using four different gears -hook and line of size 13, caste nets, gill nets, and cages of mesh sizes of 50mm, 75mm, and 100mm each. We recorded 52 fish species belonging to 17 families: 171, 236, and 169 individuals at Ogurugu, Otuocha, and Nsugbe stations respectively. Two families, Characidae, 19.5 %, and Mochokidae, 11.8%, constituted the dominant fish families in the river. The dominant fish species were Citherinus citherius, 9.02%, and Alestes nurse, 7.1%. Other fish species with significant abundance were Synodontis clarias 6.9%, Macrolepidotus curvier 5.7%, Labeo coubie 5.4%, Distichodus rostrtus 4.9%, and Schilbe mystus 4.5%. The meristic features of the two most abundant fish species caught are as follows: Citharinus citharius dorsal fins 20, anal fins 30, caudal fins 21, pectoral fins, 9 and 8 ventral fins, and Alestes nurse 10 dorsal fins, 14 anal fins, 31 caudal fins, 7 pectoral fins and 6 ventral fins. The morphometric features of the two most abundant fish species are Citharinus citharius total length 300mm, standard length 231mm, head length 69mm, body length 101mm, body girth 176 mm, body weight 900mg. Alestes nurse total length 200, standard length 140mm, head length 60mm, body length 80mm, body girth120mm, body weight 400mg. The most abundant animal utilizing the basin was Ardea cinerea(D3 with 22.2% occurrence (D4 and this was followed by Caprini with 13.51%, and Varanus niloticus, 10.04%. The least abundant animals utilizing basin were Chephalophus rufilatus, and Erythrocebus patas, with 0.58% each of occurrence. Rev. Biol. Trop. 57 (1-2: 177-186. Epub

Tropical fish community does not recover 45 years after predator introduction.

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Sharpe, D M T; De León, L F; González, R; Torchin, M E

2017-02-01

Predation is considered to be an important factor structuring natural communities. However, it is often difficult to determine how it may influence long-term, broad-scale, diversity patterns, particularly in diverse tropical systems. Biological introductions can provide powerful insight to test the sustained consequences of predation in natural communities, if pre-introduction data are available. Half a century ago, Zaret and Paine demonstrated strong and immediate community-level effects following the introduction of a novel apex predator (peacock bass, Cichla monoculus) into Lake Gatun, Panama. To test for long-term changes associated with this predator introduction, we followed up on their classic study by replicating historical sampling methods and examining changes in the littoral fish community at two sites in Lake Gatun 45 years post-introduction. To broaden our inference, we complemented this temporal comparison with a spatial analysis, wherein we compared the fish communities from two lakes with and one lake without peacock bass. Comparisons with historical data revealed that the peacock bass remains the most abundant predator in Lake Gatun. Furthermore, the collapse of the littoral prey community observed immediately following the invasion has been sustained over the past 45 years. The mean abundance of native littoral fish is now 96% lower than it was prior to the introduction. Diversity (rarefied species richness) declined by 64% post-introduction, and some native species appear to have been locally extirpated. We observed a similar pattern across invaded and uninvaded lakes: the mean abundance of native fishes was 5-40 times lower in lakes with (Gatun, Alajuela) relative to the lake without peacock bass (Bayano). In particular, small-bodied native fishes (Characidae, Peociliidae), which are common prey of the peacock bass, were more than two orders of magnitude (307 times) less abundant in Gatun and one order of magnitude (28 times) less abundant in

Características hematológicas, bioquímicas e biométricas de Piaractus mesopotamicus Holmberg, 1887 (Osteichthyes: Characidae oriundos de cultivo intensivo - DOI: 10.4025/actascibiolsci.v26i2.1647 Hematological, biochemical and biometric characteristics of Piaractus mesopotamicus Holmberg, 1887 (Osteichthyes: Characidae, reared in captivity - DOI: 10.4025/actascibiolsci.v26i2.1647

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Marcos Tavares Dias

2004-04-01

Full Text Available O estudo das características sangüíneas pode fornecer subsídios importantes para o diagnóstico e prognóstico das condições mórbidas em populações de peixes e, contribuir para a compreensão da fisiologia comparativa, relação filogenética, condições alimentares e outros parâmetros ecológicos. Foram estudados no teleósteo Piaractus mesopotamicus o eritrograma, leucograma, trombograma, a glicemia, o cortisol, a relação hepatosomática e a relação esplenosomática. Os valores da relação hepatosomática variaram de 0,67% a 2,79%, a relação esplenosomática de 0,011% a 0,108%, número de eritrócitos de 1,870 a 4,590 x 106/µL de sangue, concentração de hemoglobina de 5,7 a 12,1g/dL, hematócrito de 24,0% a 40,0%, volume corpuscular médio de 98,0 a 174,0fL, concentração da hemoglobina corpuscular média de 19,1 a 34,2g/dL, glicose plasmática de 40,6 a 89,2mg/dL e cortisol plasmático de 4,73 a 110,5ng/dL. O número de trombócitos totais variou de 12160,0 a 89280,0/µL de sangue e leucócitos de 2019,0 a 47473,0/µl de sangue. Na contagem diferencial de leucócitos foram observados 54,1% de linfócitos; 10,9% de neutrófilos; 10,3% de monócitos; 9,9% de leucócitos granulares PAS-positivos (LG-PAS; 6,7% de eosinófilos; 0,3% de basófilos e 7,8% de leucócitos imaturos. Variações intraespecíficas foram observadas em todas as características estudadas, podendo ser consideradas como normais, no que tange aos peixes. Não se deve esperar, portanto, que as características biológicas em peixes apresentem- se distribuídas normalmenteHematological characteristics are important tools for diagnosis and prognostic features in fish population and they contribute to the comprehension of comparative physiology, phylogenetic relation, food habit and other ecological parameters. Red blood cell count (RBC, white blood cell count (WBC, thrombocytes counts, glucose, cortisol, hepatosomatic and splenosomatic relation were evaluated in Piaractus mesopotamicus. The values of hepatosomatic relation varied from 0.67% to 2.79% and splenosomatic relation from 0.011% to 0.108%. RBC 1.870 to 4.590 x 10,sup>6/µL, hemoglobin concentration 5.7 to 12.1g/dL, haematocrit 24.0% to 40,0%, mean corpuscular volume 98.0 to 174.0 fL, mean corpuscular haemoglobin concentration 19.1 to 34.2g/dL, glucose 40.6 to 89.2mg/dL and cortisol 4.73 to 110.5ng/dL. The number of total thrombocytes was 12,160.0 to 89,280.0/µL and WBC 2,019.0 to 47,473.0/µL. Differential count of leucocytes showed 54.1% limphocytes, 10.9% neutrophils, 10.3% monocytes, 9.9% PAS-positive granular leukocytes (PAS-GL, 6.7% eosinophils, 0.3% basophils and 7.8% immature leucocytes. Variation of these haematological characteristics in the same fish species was observed, being considered as the normal variation in the fish concerned. Hence it is incorrect to assume that biological characteristics in fishes are distributed normally

Análise qualitativa da alimentação e o coeficiente intestinal de Metynnis cf. roosevelti Eigenmann (Characidae, Myleinae, da Lagoa Redonda, Nízia Floresta, Rio Grande do Norte, Brasil Quantitative analysis of feeding and the intestinal coefficient in Metynnis cf. roosevelti Eigenmann (Characidae, Myleinae, from Lagoa Redonda, Nízia Floresta, Rio Grande do Norte, Brazil

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Hélio de Castro Bezerra Gurgel

1994-01-01

Full Text Available This species showed feeding activily ali year long. Although zooplancton, protozooplancton and other organisms have been found in the stomaches, this species can be considered, broadly speaking, herbivorous since a great amount of seaweed was found in its diet. Fulness of the stomachs was not associated with sex difference. Full stomachs were found throughout the period. Variations according to the estimated periods were not found.

Molecular variants in populations of Bryconamericus aff. iheringii (Characiformes, Characidae in the upper Paraná river basin - doi: 10.4025/actascibiolsci.v35i2.11451

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Alberto José Prioli

2013-05-01

Full Text Available There are evidences that Bryconamericus aff. iheringii represents a species complex. DNA molecular markers have been effective in studies on phylogeny, taxonomy, and identification of cryptic species. In this study, partial sequences of genes of ATPase 6 and 8 were used to assess genetic diversity within and among populations of B. aff. iheringii of sub-basins of Tibagi, Pirapó and Ivaí rivers, belonging to the Upper Paraná river basin. The analysis of the sequences of genes pointed out high genetic diversity in B. aff. iheringii from the sub-basins studied with genetic distance values comparable to those found among different species. There was a division of the individuals into five groups. The comparison with other species of Bryconamericus that have sequences available in GenBank confirmed that the individuals studied have relevant values of genetic distance, found among different species. Nevertheless, with the available data it is not possible to refute the hypothesis that the populations correspond to a group resulting from hybridization or that there might have been introgression of mitochondrial DNA among different species.

Histología de branquias, hígado y riñón de juveniles del pez neotropical Colossoma macropomum (Characiformes, Characidae expuesto a tres temperaturas

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Luz-Marina Rojas

2013-06-01

Full Text Available Colossoma macropomum es uno de los peces tropicales de agua dulce con mayor éxito en el cultivo en aguas continentales tropicales. Se realizó una evaluación histológica de branquias, hígado y riñón de este pez expuesto a tres temperaturas (T18, T29 y T35ºC. Se utilizaron 18 ejemplares juveniles con índices biométricos de 17.87±7.88cm y 87.69±34.23g. Los análisis histológicos fueron hechos de acuerdo a técnicas previamente descritas. Se encontró que las branquias, el hígado y el riñón de los peces T29 presentaron citoarquitectura normal. Por el contrario, en las branquias de los peces T18, se observaron gotas lipídicas inmersas en el tejido branquial; los peces T35 presentaron desorganización en la estructura del tejido branquial y necrosis celular. El hígado de los peces T18, mostró hepatocitos claros y oscuros y el de T35, presentó células con granulaciones citoplasmáticas y daño en la membrana plasmática. En el riñón de los T18, se observaron alteraciones en la distribución del tejido hematopoyético. La característica más resaltante en el riñón de los peces T35, fue la desorganización del tejido glomerular. En conclusión, la temperatura de 18°C se puede considerar crítica para la cachama y la de 35ºC severa. De los tres órganos evaluados, el hígado y las branquias resultaron ser los más sensibles a los daños inducidos por las temperaturas en esta especie.

Ontogenetic, spatial and temporal variations in the feeding ecology of Deuterodon langei Travassos, 1957 (Teleostei: Characidae in a Neotropical stream from the Atlantic rainforest, southern Brazil

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Jean R. S. Vitule

Full Text Available Information related to the diet of one species always contributes to the knowledge of its bionomy and the functioning of the ecosystem in which the species lives. Therefore, understanding the feeding ecology of one fish population and its ontogenetic, spatial and temporal aspects help to understand the structure of fish assemblages and river communities. Knowledge of this structure is essential for habitat management and biodiversity conservation. The feeding ecology of Deuterodon langei Travassos, 1957 was studied through analyses of diet composition, sharing of resources, feeding strategy and contribution of food items to the width of its niche. The analysis included an assessment of ontogenetic, spatial and seasonal variations. The species was considered omnivorous with great plasticity caused by seasonal variation in food availability throughout the river basin, but mainly through ontogeny. The diet of smaller individuals revealed a predominance of insects and other arthropods, while the diet of larger specimens showed allochthonous plant items as the main components. The low intestinal quotient (IQ values for the smaller individuals were accounted for their mainly insectivorous diet. The greater relative length of the intestine can account for the greater plasticity of the adult diet, enabling them to use diet items of larger size and more difficult digestion, such as plant items. Therefore, shifts in feeding ecology during growth are confirmed in this omnivorous tropical river fish, strengthening the concept that, when comparing food habits among species, fish size must be taken into account. This study also provides needed information regarding the feeding ecology of fishes intrinsically associated with the Atlantic rainforest, one of the most threatened and biodiverse ecosystems of the planet.

Distribuição, dominância e estrutura de tamanhos da assembleia de peixes da lagoa Mangueira, sul do Brasil Distribution, dominance and sizes structure of the fish assemblage in the Mangueira lake, southern Brazil

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Luiz G. S Artioli

2009-12-01

Full Text Available Este estudo apresenta a composição de espécies, os padrões de distribuição e dominância, e a estrutura de tamanhos da assembleia de peixes em diferentes unidades de hábitat (zonas litoral, profunda e limnética costeira da lagoa Mangueira, no extremo sul do Brasil. As amostras foram obtidas no norte, centro e sul da lagoa, entre os anos de 2001 e 2007 utilizando-se de diversos amostradores (rede de emalhe, tarrafa, rede de arrasto de praia, puçá e rede de arrasto de fundo. Um total de 52 espécies foi identificado, 46 na zona litoral, 33 na limnética costeira e 26 na profunda, distribuídas em 17 famílias, das quais, Characidae, Cichlidae, Loricariidae e Atherinopsidae foram as mais diversas. As espécies dominantes somaram 91,1 %, 92,9 % e 82,7 % dos indivíduos capturados nas zonas litoral, profunda e limnética costeira respectivamente. A zona litoral é constituída de pequenos peixes, quase 70 % entre 25 e 50 mm de comprimento. Os padrões de dominância mostraram que, nesta zona, 19,5 % das espécies foram dominantes, embora quatro dessas também predominaram nas demais zonas. Na zona profunda, 7,6 % das espécies capturadas foram dominantes, com tamanhos semelhantes aos da zona litoral. Para as demais espécies, os tamanhos se assemelham aos da zona limnética costeira. A zona limnética costeira é constituída de peixes de maior porte, a maioria entre 150 e 200 mm de comprimento total, tais como os grandes caracídeos, o birú e os peixes-rei. Observou-se uma maior diferença na composição de espécies entre as zonas litoral e limnética costeira, com as espécies Jenynsia multidentata, Bryconamericus iheringii, Hyphessobrycon luetkenii e Gymnogeophagus gymnogenys dominando exclusivamente no litoral, e as espécies Oligosarcus jenynsii, Cyphocharax voga, Odontesthes perugiae e Astyanax fasciatus dominando exclusivamente a zona limnética costeira. A zona litoral apresentou diferenças na composição e dominância das esp

Mapping of the 18S and 5S ribosomal RNA genes in Astyanax altiparanae Garutti & Britski, 2000 (Teleostei, Characidae from the upper Paraná river basin, Brazil

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Carlos Alexandre Fernandes

2006-01-01

Full Text Available Fluorescence in situ hybridization (FISH was undertaken in order to determinate the chromosomal distribution pattern of 18S and 5S ribosomal DNAs (rDNA in four populations of the characid fish Astyanax altiparanae from the upper Paraná river basin, Brazil. The 18S rDNA probe FISH revealed numerical and positional variations among specimens from the Keçaba stream compared to specimens of the other populations studied. In contrast to the variable 18S rDNA distribution pattern, highly stable chromosomal positioning of the 5S rDNA sites was observed in the four A. altiparanae populations. Divergence in the distribution pattern of 18S and 5S rDNA sites is also discussed.

Range extension of Moenkhausia oligolepis (Günther,1864 to the Pindaré river drainage, of Mearim river basin, and Itapecuru river basin of northeastern Brazil (Characiformes: Characidae

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Erick Cristofore Guimarães

2016-08-01

Full Text Available The present study reports range extansion of Moenkhausia oligolepis to the Pindaré river drainage, of the Mearim river basin, and Itapecuru river basin, Maranhão state, northeastern Brazil. This species was previously known only from Venezuela, Guianas, and the Amazon River basins. In addition, we present some meristic and morphometric data of the specimens herein examined and discuss on its diagnostic characters.

EVALUACIÓN DE NUEVA TECNOLOGÍA PARA MITIGAR LAS ESPINAS INTRAMUSCULARES EN FILETES DE CACHAMA Piaractus brachypomus (Pisces: Characidae EVALUATION OF NEW TECHNOLOGY TO MITIGATE INTRAMUSCULAR THORNS IN CACHAMA FILLETS

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Héctor Suárez Mahecha

2009-06-01

Full Text Available La presencia de espinas intramusculares en filetes de cachama dificulta la comercializacion y demanda por parte de los consumidores. Hasta el momento no existen tecnologías que permitan ofrecer filetes de cachama que garanticen condiciones de seguridad frente a las espinas. El objetivo del presente trabajo fue evaluar una nueva tecnología para mitigar la presencia de espinas en filetes de cachama Piaractus brachypomus empacados al vacío y almacenados durante 30 días a 3±0,5 °C. A filetes en presentación lateral interna fueron realizados cortes profundos, paralelos y perpendiculares al eje longitudinal, a una distancia de 3 mm entre cada corte, en sentido dorso-ventral. Fueron realizados análisis microbiológico, fisicoquímico y sensorial. El análisis microbiológico muestra condiciones aceptables para el final del periodo de almacenamiento. Los valores obtenidos para este periodo, fueron de log UFC/g 7,07; 4,7 y 1100 NMP, 18 NMP para organismos psicrotrofilos, mesófilos, coliformes totales y coliformes fecales, respectivamente. No fue determinada presencia de Salmonella ni de organismos sulfito reductores. El análisis fisicoquímico mostró valores de 39,36 para BVT-N; 6,22 pH; 3,3% de pérdida de humedad 1,52; ácido tiobarbitúrico mg MA/kg. El efecto del sajado no incrementó los valores de oxidación de ácidos grasos, ni aumentó las BVT que pudiesen indicar degradación de la proteína. En el análisis sensorial los filetes sometidos a cocción fueron rechazados solamente a partir del día 25 del periodo de almacenamiento, para los atributos aroma y sabor. Durante la evaluación los panelistas no encontraron presencia de espinas, mostrando que la temperatura de cocción utilizada y los cortes en las espinas, permiten degradar la espina intramuscular evitando que sea detectada.The presence of pin bones in cachama fillets makes marketing and demand difficult by the consumers. So far, there are no technologies to provide cachama fillets to ensure security conditions about thorns. This work had as objective to assess a new technology to mitigate the presence of thorns in cachama fillets Piaractus brachypomus vacuum packed and stored for 30 days at 3±0.5 °C. To fillets in lateral internal presentation were made deep cuts, parallel and perpendicular to the longitudinal axis, at a distance of 3 mm between each court, in a back-ventral. Microbiological, physicochemical and sensory analysis were made. Microbiological analysis shows acceptable conditions at the end of storage period. The obtained values for this storage period were 7.07x106 CFU mL, 4.7x106 CFU mL, 1100 NMP, 18 NMP for psychrotrophics organisms, mesophiles, total and fecal coliforms, respectively. There was no presence of Salmonella nor sulphite reductor organisms. Physicochemical analysis showed values of 39.36 for BVT-N; 6.22 pH; 3.3% of moisture loss; 1.52 thiobarbituric acid mg MA/kg. Cutting effect did not increase oxidation values of fatty acids, nor increased the BVT that could indicate protein degradation. In sensory analysis, fillets subjected to cooking were rejected only since the day 25 of storage period for aroma and flavor attributes. During the assay panelists found no presence of thorns, showing that cooking temperature used and cuts in thorns, allow degrade pin bones avoiding their detection.

Parâmetros populacionais e simulação do rendimento por recruta de Salminus brasiliensis (Cuvier, 1816 do alto rio Paraná - DOI: 10.4025/actascibiolsci.v26i3.1593 Population parameters and simulation of the yield per recruit of Salminus brasiliensis (Cuvier, 1816 from the upper Paraná River - DOI: 10.4025/actascibiolsci.v26i3.1593

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Angelo Antonio Agostinho

2004-04-01

Full Text Available O dourado Salminus brasiliensis é uma espécie explorada por todos os tipos de pesca na bacia do rio Paraná e sua captura tem sido diminuída nos últimos anos. Nesse contexto, o presente trabalho tem por objetivo simular o rendimento por recruta de S. brasiliensis partindo da necessidade de rever a regulamentação de pesca, na tentativa de conservar os estoques da espécie. Para realizar o trabalho, foram usados os dados de captura junto aos pescadores profissionais do município de Porto Rico, Estado do Paraná, no período de outubro de 1986 a setembro de 1988, amostrados com redes de espera, com linha e anzol, com espinhéis e com anzóis de galho. A simulação do rendimento por recruta foi realizada considerando diversos cenários de mortalidade por pesca e comprimentos mínimos de captura, a partir do modelo de rendimento de equilíbrio de Beverton e Holt, modificado por Jones. A simulação mostrou um incremento no rendimento por recruta para os comprimentos mínimos de 60 e de 65cm, sugerindo que mudanças na legislação em vigor devem ser consideradas. Além disso, sugerimos mudanças nos procedimentos operacionais das barragens, na época de reprodução da espécie, e proteção da pesca nos locais de desova e nos criadouros naturaisThe “dourado” Salminus brasiliensis (Characidae is caught in all types of fisheries conducted in the upper Paraná River. However, a decline has been observed in the quantity of S. brasiliensis harvested in recent years. In this paper, we deal with simulation of yield per recruit, in order to evaluate ongoing fishery regulation. We expect to generate information that guides the conservation of this species. Data from the artisanal fishery were gathered from October 1986 to September 1988, in the city of Porto Rico. In that region, to catch the “dourado”, fishers use gillnets, hook and line, long lines and branch hooks. Simulations of yield per recruit were performed under diverse scenarios of

Determinação da razão ótima de espermatozóides por ovócitos de piabanha Brycon insignis (pisces - characidae Determination of the optimum ratio of spermatozoa per oocyte of the piabanha Brycon insignis

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E. Shimoda

2007-08-01

Full Text Available Determinou-se a razão ótima de espermatozóides por ovócitos da piabanha Brycon insignis, utilizando-se dois machos e duas fêmeas da espécie, submetidos ao procedimento de desova induzida. Os gametas foram extrusados manualmente 200 horas-grau após a aplicação do extrato bruto de hipófise. Os ovócitos foram misturados e deste pool retiraram-se amostras com 2g de ovócitos (701 ovócitos/g. O sêmen do pool foi diluído em solução de NaCL 1,2% de tal forma que, após a adição de 1ml do sêmen diluído aos ovócitos, fossem obtidas as seguintes razões espermatozóides por ovócitos em cada tratamento: T1=86.662, T2=173.324, T3=259.986, T4=346.648 e T5=433.310. A taxa de fertilização do sêmen não diluído usado como controle foi de 65,3%. Após ativação espermática com NaHCO3 1% e fecundação, os ovos foram transferidos para as incubadoras e nelas foram observadas as seguintes percentagens de fertilização em relação à do grupo-controle: T1=35,7%, T2=53,1%, T3=79,1%, T4=93,4% e T5=87,8%. A percentagem de fertilização (em relação ao controle aumentou de forma linear, segundo a equação de regressão: Y=15,55+0,0002297X (PThe optimum spermatozoa:oocyte ratio of piabanha Brycon insignis was studied. Two males and two females were induced to spawn, and the gametes were stripped after 200 hourgrades starting from the application of carp pituitary gland. Oocytes from two females were mixed, and samples of 2g (701 oocytes/g were collected from the obtained pool and placed into plastic cups. The semen from the two males, after mixed to compose a pool, was diluted in NaCl solution (1.2% so that, after the addition of 1ml of diluted sperm into the oocytes, the following spermatozoa:oocyte ratios (tri-replicated were obtained: T1=86,662, T2=173,324, T3=259,986, T4=346,648 and T5=433,310. After the activation using 1% NaHCO3 and fertilization, the eggs were transferred to incubators, and observed the percentages of fertilization relative to the control. T1=35.7%, T2=53.1%, T3=79.1%, T4=93.4% and T5=87.8%. Undiluted semen was used as "control", which showed 65% of fertilization. The percentage of fertilization (relative to the control increased linearly according to the regression Y= 15.55 + 0.0002297X (P<0.01; R²=0.98, until the proportion of 314,481 spermatozoa per oocyte, and, from this point, the fertilization rate maintained at 88%.

Histología de branquias, hígado y riñón de juveniles del pez neotropical Colossoma macropomum (Characiformes, Characidae expuesto a tres temperaturas Histology of gill, liver and kidney in juvenile fish Colossoma macropomum exposed to three temperatures

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Luz-Marina Rojas

2013-06-01

Full Text Available Colossoma macropomum es uno de los peces tropicales de agua dulce con mayor éxito en el cultivo en aguas continentales tropicales. Se realizó una evaluación histológica de branquias, hígado y riñón de este pez expuesto a tres temperaturas (T18, T29 y T35ºC. Se utilizaron 18 ejemplares juveniles con índices biométricos de 17.87±7.88cm y 87.69±34.23g. Los análisis histológicos fueron hechos de acuerdo a técnicas previamente descritas. Se encontró que las branquias, el hígado y el riñón de los peces T29 presentaron citoarquitectura normal. Por el contrario, en las branquias de los peces T18, se observaron gotas lipídicas inmersas en el tejido branquial; los peces T35 presentaron desorganización en la estructura del tejido branquial y necrosis celular. El hígado de los peces T18, mostró hepatocitos claros y oscuros y el de T35, presentó células con granulaciones citoplasmáticas y daño en la membrana plasmática. En el riñón de los T18, se observaron alteraciones en la distribución del tejido hematopoyético. La característica más resaltante en el riñón de los peces T35, fue la desorganización del tejido glomerular. En conclusión, la temperatura de 18°C se puede considerar crítica para la cachama y la de 35ºC severa. De los tres órganos evaluados, el hígado y las branquias resultaron ser los más sensibles a los daños inducidos por las temperaturas en esta especie.Water temperature is an important factor that affects growth and antioxidant enzyme activities in fish, and when adverse, it may trigger diseases in fish populations. C. macropomum is a freshwater neotropical fish widely distributed in South America and abundant in river basins as the Amazon and Orinoco. It is highly used for intensive aquaculture development and is a very important product for the local riverside economy in Venezuela. The purpose of our study was to examine the water temperature effect on gills, liver and kidneys of juvenile fishes of C. macropomum. Eighteen juveniles with biometrical index of 17.87±7.88cm and 87.69±34.23g were respectively exposed to three culture temperatures (T18, T29 and T35ºC during a period of 21 days. Histological analyses on gills, liver and kidney were made according to standard methodologies. Our results showed that these tissues exhibited normal citoarchitecture at T29. On the contrary, T18-gills displayed brachiallipid droplets inside brachial epithelium; and disorganization in the brachial tissue was observed at T35. Furthermore, we observed two kinds of hepatocytes (dark and light on T18°C-liver. The T35-liver samples showed cytoplasmatic granulation and damages in cytoplasmatic membrane. Kidney samples from T18 observed alterations in the cellular distribution of the hematopoietic tissue; while, at T35, the most important feature observed was the disorganization of the glomerular structure. We concluded that T18 and T35 are respectively critical and severe temperatures to C. macropomum; besides, the most sensible tissues to changes induced by temperature in this species were the liver and gills.

Variação espaço-temporal na distribuição e abundância de Moenkhausia sanctaefilomenae (Characiformes: Characidae em lagoas da planície de inundação do rio Cuiabá, Pantanal, Brasil=Spatial-temporal variation of the distribution and abundance of Moenkhausia sanctaefilomenae at lagoons of the Cuiaba river floodplain, Pantanal, Brazil

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Jerry Penha

2012-01-01

Full Text Available Identificar os fatores bióticos e abióticos que determinam a variação na distribuição e abundância das populações, tornou-se nos últimos anos um grande desafio para os ecologistas. Assim neste estudo foram avaliados o efeito das variáveis abióticas e a abundância de predadores sobre a abundância de Moenkhausia sanctaefilomenae, a variação no comprimento médio dos indivíduos entre lagoas e períodos e o efeito das variáveis abióticas e da abundância de predadores sobre a estrutura em comprimento. Foram amostradas 16 lagoas da planície de inundação do rio Cuiabá, no período de junho (vazante, setembro (seca e dezembro (enchente de 2005 e março (cheia de 2006. Para M. sanctaefilomenae, a distribuição é mais ampla e a abundância é maior no final da vazante, início da seca, reduzindo-se gradualmente ao longo dos períodos de seca, enchente e cheia. Adicionalmente, o período afeta a estrutura em tamanho das populações, que são espacialmente homogêneas. Indivíduos menores foram capturados no final do período de vazante e os maiores ao início da enchente. Durante o final da vazante/início da seca, a variação espacial na abundância da população foi relacionada positivamente com o pH, o oxigênio dissolvido e cobertura de macrófitas e área da lagoa, mas, não com a abundância local de predadores na zona litorânea das lagoas.Identifying the biotic and abiotic factors that determine the variation in the distribution and abundance of populations has become a great challenge for the field of ecology in recent years. Thus, in this study we evaluated the effect of abiotic variables and the abundance of predators on the abundance of Moenkhausia sanctaefilomenae, the variation in the average length of the individuals between lakes and periods, and the effect of the abiotic variables and abundance of predators on the structure in length of that species. Sixteen lakes of the Cuiabá river flood plain were sampled in June (drying period, September (dry period and December (flooding period 2005 and March (flood period 2006. For M. sanctaefilomenae, the distribution is ampler and the abundance is greater at the end of the drying period, beginning of dry season, reducing gradually over the periods of dry, drying and flood season. Additionally, the period affects the structure in size of the populations that are spatially homogeneous. Smaller individuals were captured at the end of the drying period and the larger individuals at the start of flooding. During the end of the drying period and in the beginning of the dry season, the spatial variation in the abundance of the population was positively related with pH, dissolved oxygen and macrophyte cover and area of the lake, but not with the local abundance of predators in the littoral zone of the lakes.