47 research outputs found

    Relaciones longitud-peso y factor de condición estacional y anual de dos especies de Sciaenidos Micropogonias furnieri y Cynoscion guatucupa del Río de la Plata y costa oceánica uruguaya (Atlántico Suroeste)

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    En este trabajo se analizaron las relaciones longitud-peso y el factor de condición de Micropogonias furnieri y Cynoscion guatucupa en diferentes épocas [verano; otoño; invierno, primavera y años (2006, 2007 y 2011)] a partir de muestreos mensuales de desembarques de la flota costera uruguaya que operó en el Río de la Plata y costa oceánica uruguaya. Fueron analizados 9.146 individuos de M. furnieri (entre 15-69 cm de longitud total) y 5.285 individuos de C. guatucupa, (entre 21-54 cm de longitud total). Para ambas especies, el coeficiente de alometría fue negativo (b 3). Para M. furnieri, las pendientes no mostraron diferencias significativas entre el 2006 y 2007, mientras que el 2011 presentó diferencias significativas con ambos años. Para C. guatucupa no se encontraron diferencias significativas entre el 2007 y 2011, pero si cuando ambos años fueron comparados con el 2006. Los mayores valores del factor de condición fueron obtenidos en verano de 2006 y durante el verano y otoño del 2007 para M. furnieri, mientras que para C. guatucupa fueron en invierno 2006 y otoño 2007. Para ambas especies el factor de condición mostró diferencias significativas estacionales y anuales. Este trabajo presenta la primera referencia del factor de condición para estas especies de Sciaenidos en el área de estudio.The present study analyses the seasonal (summer: January, February, March; autumn: April, May, June; winter: July, August, September and spring: October, November, December) and annual (2006, 2007 and 2011) length-weight relationships and condition factors of Micropogonias furnieri and Cynoscion guatucupa from Río de la Plata and the Uruguayan ocean coast from data collected throught monthly landings by the Uruguayan coastal fleet in the Montevideo port (Uruguay). A total of 9,146 individuals of M. furnieri ranging from 15 to 69 cm total length (LT); and 5,285 individuals of C. guatucupa, ranging from 21 to 54 cm LT were analyzed. For both species, the allometry coefficients showed that growth in the majority of seasons were negative (b 3). For M. furnieri, no significant differences among slopes were found between 2006 and 2007 whereas 2011 showed significant differences compared to 2006 and 2007. For C. guatucupa no significant differences among slopes were found between 2007 and 2011, whereas 2006 showed significant differences with other years. The highest values for the condition factor in M. furnieri were recorded in summer 2006, and during the summer and autumn 2007 and for C. guatucupa in winter 2006 and autumn 2007. Significant seasonal and annual differences for condition factors were found for both species. This work provides the first reference regarding condition factor for both sciaenid species in the study area

    Size and sex composition of two species of the genus Atlantoraja (Elasmobranchii, Rajidae) caught by the bottom trawl fisheries operating on the Uruguayan continental shelf (southwestern Atlantic Ocean)

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    In this work we analyzed the spatial and seasonal variation of length distribution, sexual proportion and mature dominance for Atlantoraja cyclophora and A. castelnaui, at the Uruguayan continental shelf. There were significant differences in total length (TL) composition between sexes, being females bigger than males for both species. Atlantoraja cyclophora showed a relatively uniform length distribution between inner and outer shelf. There were no major variations in the sex compositions and in the mature dominance between seasons, suggesting no temporal variation. Atlantoraja castelnaui showed a significant variation in its spatial and seasonal distribution. Individuals were smaller in inner shelf, pointing out the existence of juvenile zone in areas up to 50 m depth. A tendency to capture smaller individuals towards the end of the year was observed. In all seasons over 50% of females were caught below the estimated size at maturity, suggesting that this species is highly susceptible to exploitation.Neste trabalho foi analisada a variação espacial e temporal da distribuição de comprimento, proporções sexuais e dominância de maduros para Atlantoraja cyclophora e A. castelanui, na plataforma continental uruguaia. Houve diferenças significativas na distribução do comprimento total (TL) entre os sexos, sendo as fêmeas maiores que os machos para ambas espécies. Atlantoraja cyclophora mostrou uma distribuição relativamente uniforme de comprimento entre a prataforma interna e externa. Não houviram grandes variações nas composições do sexo e na dominância de maduros entre as estações do ano, sugerindo que não ha variação temporal. Atlantoraja castelnaui mostrou uma variação significativa na sua distribuição espacial e sazonal. Os indivíduos foram menores na plataforma interna, apontando para a existência de uma zona de juvenis em áreas de até 50 m de profundidade. A tendência para a captura de indivíduos menores no final do ano foi observada. Em todas as estações do ano mais de 50% das fêmeas foram capturadas em um comprimento menor ao tamanho estimado de maturidade observado na literatura, sugerindo que esta espécie é altamente suscetível à explotação

    Novel host report for Catadiscus uruguayensis Freitas & Lent, 1939 (Trematoda, Diplodiscidae) infecting Austrolebias Costa, 1998 species from Uruguay

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    The genus Catadiscus Cohn, 1904 has a total of 16 known species that infect the intestinal tract of reptiles, amphibians, and mollusks. However, Catadiscus has never been found in teleosts. The annual fish Austrolebias prognathus (Amato, 1986) and A. cheradophilus (Vaz-Ferreira, Sierra de Soriano & Scaglia de Paulete, 1965) were collected from temporary ponds in the southeast of Uruguay. The specimens found in the intestinal tract of these hosts were morphologically identified as Catadiscus uruguayensis Freitas & Lent, 1939, which until now were only known to infect amphibians. This work represents the first report of the genus Catadiscus infecting and developing in a fish host

    Long term fish assemblages as units of management in a temperate estuary (Rio de La Plata - SW Atlantic Ocean)

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    Demersal fish assemblages from trawl surveys in the Rio de la Plata estuary and its inner continental shelf were analyzed from 1975 to 1995. The first two factors of Principal Component Analysis explained 48% of the variance in species distribution, and they are consistent with the results of a cluster analysis. The analysis indicated the existence of three spatially and temporally distinct fish assemblages: internal and external estuarine and inner continental shelf (Uruguayan coastal assemblages). These assemblages were persistent considering the environmental characteristics and their species composition. Despite the changes registered in the species density during the period surveyed, the fish assemblages tend to persist over time. It was demonstrated that the assemblages can be considered as open systems and that there exists a reciprocal flow of organisms between adjacent associations. However, each assemblage showed high spatial and temporal persistence in accordance with the environmental characteristics of the system analyzed. Therefore, and according to the multispecies fisheries operating in the system, each assemblage defined could be considered a unit of management.Foram analisadas as associações dos peixes demersais provenientes de arrastos de prospecção no estuário do Rio de la Plata e sua plataforma interna no período de 1975 a 1995. Os dois primeiros fatores da Análise de Componentes Principais explicaram 48% da variância na distribuição das espécies sendo consistentes com os resultados da análise de agrupamento. Os resultados mostraram a existência de três associações de peixes espacial e temporalmente distintas: uruguaia costeira, estuarina externa e estuarina interna. Essas associações foram consistentes quanto às características ambientais e de composição de espécies. A despeito das mudanças registradas na densidade das espécies ao longo do período analisado, as associações de peixes foram persistentes ao longo do tempo. No presente trabalho foi demonstrado que embora as associações sejam consideradas um sistema aberto, um fluxo recíproco de organismos acontece entre associações adjacentes. Contudo, cada associação apresenta diferentes graus de estabilidade, dependentes da estabilidade física e temporal do habitat, e das interações das espécies nas associações. No entanto, cada associação mostrou alta persistência espacial e temporal, apesar da variabilidade ambiental no sistema analisado. Nesse sentido, e de acordo com a pesca multiespecífica que opera neste sistema, cada associação poderá ser considerada como uma unidade de gestão

    Novel host report for Catadiscus uruguayensis Freitas & Lent, 1939 (Trematoda, Diplodiscidae) infecting Austrolebias Costa, 1998 species from Uruguay

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    The genus Catadiscus Cohn, 1904 has a total of 16 known species that infect the intestinal tract of reptiles, amphibians, and mollusks. However, Catadiscus has never been found in teleosts. The annual fish Austrolebias prognathus (Amato, 1986) and A. cheradophilus (Vaz-Ferreira, Sierra de Soriano & Scaglia de Paulete, 1965) were collected from temporary ponds in the southeast of Uruguay. The specimens found in the intestinal tract of these hosts were morphologically identified as Catadiscus uruguayensis Freitas & Lent, 1939, which until now were only known to infect amphibians. This work represents the first report of the genus Catadiscus infecting and developing in a fish host.Centro de Estudios Parasitológicos y de Vectore

    Genetic and morphometric analyzes of Paralichthys species confirm the presence of P. brasiliensis in the Uruguayan waters

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    Paralichthys species have high commercial value and constitute a resource for demersal fisheries in the Southwestern Atlantic Ocean. Although six species have been described based on morphological characters for the Uruguayan and Argentinean waters, only the presence of three species is accepted, being their distribution still uncertain. Genetic tools are useful for species identification as a complement of morphological characters. This paper determines the genetic and morphometric variation between three species of Paralichthys that inhabiting Uruguayan waters. The interorbital width (IN) and the length from the mouth to the dorsal fin base (SD) of P. patagonicus differed significantly from the other two species (P. orbignyanus and P. brasiliensis). From a morphological perspective, individuals identified as P. orbignyanus formed two different groups. Clade Po_A included those belonging to oceanic coastal waters of Uruguay and deeper waters of the Rio de la Plata together with individuals of P. brasiliensis from ItajaÃ, Santa Catarina (Brazil). Individuals collected in the Rio de la Plata coastal and beach zone formed the clade Po_B group. Genetic analysis confirmed for the first time the presence of P. brasiliensis in Uruguayan and Rio de la Plata shelf waters and extends its known distribution area further south. Discriminant scores for P. orbygnianus separate individuals in two groups corresponding to the presence of two species. Molecular and morphological analysis showed individuals in the clade Po_A includes those collected in Uruguayan waters together with those collected in northern Brazilian waters belonging to the species P. brasiliensis

    Seksualni razvoj i reproduktivni ciklus raže okatice Atlantoraja cyclophora (Regan, 1903), (Chondrichthyes: Rajidae: Arhynchobatinae) u južnom Brazilu

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    Specimens of Atlantoraja cyclophora were collected monthly from commercial fishing landings at Guarujá, São Paulo State, Brazil, from March 2005 to April 2006 at depths between 10 and 146 m. Males ranged from 13.3 to 58.5 cm TL (n = 396). Both the smallest mature male and the largest immature male were 47.0 cm long. Males’ size-at-50% maturity was calculated to be 46.3 cm. Females ranged from 11.5 to 68.0 cm (n = 401). The smallest mature and the largest immature female were 51.6 and 53.0 cm long respectively. For the females, size-at-50% maturity was calculated to be 53.2 cm. In the males the hepatosomatic and gonadosomatic indices varied between 0.48 (August) and 3.54 (November) and between 0.15 (November) and 1.45 (June) respectively, with no significant variation for the fourteen-month period. In the females the hepatosomatic and gonadosomatic indices varied from 1.55 and 6.30 3.54 (both for April 2006) and from 0.08 (December) to 4.41 (October) respectively, with no significant difference among months. Egg-bearing females were found in all months with proportions varying from 0.03 (March) to 0.67 (April). Both males and females undergo an annual cycle, with slight seasonal variations in reproductive activity and a peak in the proportion of egg bearing females between April and July.Jedinke raže okatice, Atlantoraja cyclophora prikupljene su mjesečno iz gospodarskih lovina u Guarujáu, država São Paulo, Brazil, od ožujka 2005. do travnja 2006. na dubinama od 10 do 146 metara. Duljina mužjaka kolebala je od 13.3 do 58.5 cm TL (n=396). Najmanji spolno zreli mužjak i najveća spolno nezrela ženka bili su dugi 47.0 centimetara. Izračunata dužina mužjaka pri stadiju 50% zrelosti populacije je iznosila 46.3 cm. Dužina ženki se kretala u rasponu od 11.5 do 68.0 cm (n=401). Najmanja spolno zrela i najveća nezrela ženka su bile dugačke 51.6 cm, odnosno 53.0 cm. Izračunata dužina ženki pri stadiju 50% zrelosti populacije je iznosila 53.2 cm.Kod mužjaka su hepatosomatski i gonadosomatski indeks kolebali od 0.48 (kolovoz) i 3.54 (studeni) i između 0.15 (studeni) i 1.45 (lipanj) bez značajnih kolebanja tijekom razdoblja od četrnaest mjeseci. Kod ženki su hepatosomatski i gonadosomatski indeks kolebali od 1.55 do 3.54 (oba u travnju 2006.) i između 0.08 (prosinac) i 4.41 (listopad), bez značajnijih mjesečnih kolebanja. Ženke s jajima su bile nazočne tijekom svih mjeseci u razmjerima koji su kolebali od 0.03 (ožujak) do 0.67 (travanj). I mužjaci i ženke prolaze kroz svoj godišnji ciklus, sa neznatnim sezonskim kolebanjima u reproduktivnoj aktivnosti i maksimumom u proporciji ženki s jajima između travnja i srpnja

    Focused ultrasound to diagnose HIV-associated tuberculosis (FASH) in the extremely resource-limited setting of South Sudan: a cross-sectional study

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    Our cross-sectional study aimed at evaluating the diagnostic performance of Focused Assessment with Sonography for HIV-associated tuberculosis (FASH) to detect extrapulmonary tuberculosis in extremely resource-limited settings, with visceral leishmaniasis as a differential diagnosis with overlapping sonographic feature
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