239 resultados para Prochilodus lineatus


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O gênero Prochilodus é amplamente distribuído pela América do Sul, incluindo várias espécies que apresenta certo grau de endemismo nas diferentes bacias. Essas espécies alimentam-se basicamente de detritos orgânicos, organismos do benton, e alimentações artificiais. O objetivo deste estudo foi testar três densidades de estocagem (0,5, 0,75, e 1 larva/litro) e dietas contendo dois níveis diferentes de proteína bruta (35 e 40% PB) nos parâmetros do crescimento e na taxa da sobrevivência do curimbatá, Prochilodus scrofa. As larvas foram estocadas em aquários experimentais de 100 litros, mantidos com volume de 60 litros, com o fluxo de água contínuo, proveniente de poço semi-artesiano. A maior média foi proporcionada pela ração com 40% de PB (1,66g ± 0,21). As diferenças foram significativas para os efeitos dos teores de PB sobre o ganho de peso e densidades de estocagem, na sobrevivência das larvas. Para o ganho de peso, as melhores médias foram obtidas com nível de 40% de PB (2,50g ± 0,40) e para a sobrevivência, as melhores taxas foram 94,45% ± 19,32 e 78,87% ± 19,32 nas densidades de 0,5 e 0,75 larvas/litro, respectivamente.

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1. 1. Routine oxygen consumption and blood glucose were determined from freshwater fishes, Prochilodus scrofa and Cyprinus carpio, exposed at high temperatures for 1 hr. 2. 2. Prochilodus scrofa had a significantly higher rate of oxygen consumption at 30°C than at 25°C, and carp higher at 25°C than at 30°C. 3. 3. Blood glucose was significantly higher for Cyprinus carpio than for Prochilodus scrofa at 25 and 30°C; however, after exposure to these temperatures for 1 hr blood glucose did not change significantly for both species. 4. 4. The results suggest that these interspecific variations may be linked to the differences between native and foreign fishes and their way of life. © 1985.

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The seminiferous tubules of Prochilodus scrofa present a coiled morphological arrangement with intertubular anastomoses and unrestricted spermatogonial distribution. The structural pattern of the seminiferous tubules is cystic, with cysts formed by cytoplasmic prolongations of Sertoli cells. Inside the cysts are observed different types of germ cells. The seminiferous tubules open individually on the ventral surface of the main testicular duct present in each testis. Each main testicular duct prolongs as a spermatic duct, fusing with the spermatic duct of the opposite side to form the common spermatic duct which opens into the urogenital papilla. The mature sperm cysts break and extravasate their content into the lumen of the seminiferous tubules from which the seminal fluid and the spermatozoa penetrate the main testicular duct, the spermatic duct and the common spermatic duct for semen ejaculation.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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This research focuses on reproductive biology and pollination ecology of entomophilous angiosperms, with particular concern to reproductive success in small and isolated populations of species that occur at their distribution limits or are endemic. I considered three perennial herbs as model species: Primula apennina Widmer, Dictamnus albus L. and Convolvulus lineatus L. I carried out field work on natural populations and performed laboratory analyses on specific critical aspects (resource allocation, pollen viability, stigmatic receptivity, physiological self-incompatibility, seed viability), through which I analysed different aspects related to plant fitness, such as production of viable seed, demographic structure of populations, type and efficiency of plant-pollinator system, and limiting factors.

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ENGLISH: This study is based on collections of larvae of Thunnus albacares, Euthynnus llneatus, and Auxis sp. obtained from surface and oblique net tows made during seven cruises, each along a comparable track in the entrance of the Gulf of California and each during a different month. Concomitant measurements of surface temperature, salinity, and zooplankton were made at each of the plankton stations. The catches of larval Auxis sp. were examined by analysis of variance techniques to determine which environmental features were associated with the spawning of this tuna as indicated by the distribution of larvae and to gain some insight into the behavior of the larvae themselves. The testing indicated that the spawning of Auxis sp. varied significantly among the different months of the cruises. The testing also indicated that if the larvae were capable of avoiding the sampling apparatus, this ability was not related to features associated with time of day such as light conditions. The analysis did not detect any change in the vertical distribution of the larvae among the months of the experiment. It was concluded that the larvae did not exhibit a diel vertical movement. The measurements of temperature, salinity, and zooplankton volumes were treated as covariates in the analysis. The surface temperature proved to be a highly important factor in explaining the distribution of larvae, but salinity and zooplankton volumes were not. Catches of Thunnus albaeares and Euthynnus lineatus were rare during the course of the study; these are discussed in qualitative terms with respect to the time of the year and the surface temperature. The distribution of larval tunas in the area of study was compared with the distribution of surface water masses. It appeared that these masses had no influence per se on the distribution of larvae. SPANISH: Este estudio está basado en las recolecciones de larvas de Thunnus albacares, Eutbynnus lineatus, y Auxis sp. obtenidas según los arrastres superficiales y oblicuos de la red, realizados durante siete cruceros, cada uno a la entrada del Golfo de California a lo largo de un derrotero comparable, y cada uno durante distintos meses. Las mediciones correspondientes de la temperatura superficial, salinidad y de zooplancton se realizaron en cada una de las estaciones de plancton. Las capturas de larvas Auxís sp. fueron examinadas mediante el análisis de la varianza para determinar cuales características ambientales se encontraban asociadas con el desove de este atún según lo indicaba la distribución de las larvas, y para obtener alguna idea del comportamiento de las larvas en sí mismas. Las pruebas indicaron que el desove de Auxis sp. varió significativamente entre los diferentes meses de los cruceros; indicaron también que si las larvas eran capaces de evitar el aparato de muestreo, esta habilidad no se relacionaba a las características asociadas con la hora del día de acuerdo a las condiciones de luz. El análisis no demostró ningún cambio en la distribución vertical de las larvas durante los meses del experimento. Se determinó que las larvas no exhiben un movimiento vertical diario. Las mediciones de temperatura, salinidad, y de los volúmenes de zooplancton fueron tratadas como covariables en el análisis. La temperatura superficial demostró ser un factor altamente importante en la explicación de la distribución de las larvas, pero la salinidad y los volúmenes de zooplancton no lo fueron. Las capturas de Thunnus albacares y Eutbynnus lineatus fueron pocas durante el curso de este estudio; éstas se discuten en términos cualitativos respecto a la época del año y a la temperatura superficial. La distribución de los atunes larvales en el área de estudio fue comparada con la distribución de las masas superficiales de agua. Parece que estas masas no tienen influencia per se en la distribución de las larvas. (PDF contains 40 pages.)

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The paper assessed qualitatively the threat status of nigerian freshwater fishes that are presently being exported and those that have potential in aquarium trade using such criteria as rarity, size at maturity, mode of reproduction, human population density, habitat degradation, pollution and range of each species among others. For their conservation captive breeding of these fishes were proffered with information that can assist collectors, exporter and aquaculturists that wants to breed polypterids, Butterfly fish, Knife fish, Elephantfish, Pollymyrus isidori, Arnordichthys spilopterus, Nannaethiops unitaeniatus, Killifishes, Polycentropsis abbreviatta, Cichlids, Ctenpomas, Mastacembelids and Tetraodon lineatus

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The von Bertalanffy growth function is used for length based analysis of growth and mortality patterns for management of fisheries. However, certain fish have growth patterns that the VBGF may not be able to describe adequately.e.g. the Acanthurus lineatus in Samoa. In such cases a two phase VBGF may be a useful approach.

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The microhabitat breadth of Vamanapuram River fish community was studied in detail. The microhabitat variables selected were relative depth, focal point velocity, water column depth, mean water velocity and substrate. Puntius filamentosus had the highest breadth in three dimensions in both stream and river habitats showing a generalistic mode of resource utilization. Garra mullya, Labeo dero and Glossogobius giuris are specialists in the usage of microhabitat variables in the stream habitat while these are G. mullya, Etroplus maculatus and Aplocheilus lineatus in river habitat. Danio aequipinnatus showed extreme variations along focal point velocity variable in both habitats indicating an. opportunistic behaviour.

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Ying-Gui Dai and Jun-Xing Yang (2003) Phylogeny and zoogeography of the cyprinid hemicultrine group (Cyprinidae: Cultrinae). Zoological Studies 42(1): 73-92. The hemicultrine group consists of middle-sized cyprinids in Asia which taxonomically belong to the subfamily Cultrinae in the Cyprinidae (Cypriniformes), but there has been no convincing generic phylogenetic hypothesis proposal so far. On the basis of a morphological study of 65 specimens soaked in formalin and 14 skeletal specimens of 8 species in 6 genera within the hemicultrine group as an ingroup, a 70-character matrix was obtained. The generic phylogenetic relationships of the hemicultrine group are hypothesized with the matrix by the method of cladistic analysis. When the species Rasborinus lineatus or Cultrichthys erythropterus is used as the sole outgroup, the matrix gives the same single most-parsimonious tree of generic phylogenetic relationships within the hemicultrine group which shows that the hemicultrine group forms a monophyletic group. However, when Rasborinus lineatus is used as the sole outgroup and Cultrichthys erythropterus and Paralaubuca barroni are included in the ingroup, the hemicultrine group is validated to represent a paraphyletic group, and the hemicultrine group and the genus Paralaubuca form a monophyletic group. The tree of generic relationships and zoogeography of the monophyletic group comprising the hemicultrine group and the genus Paralaubuca suggest the following: (1) The monophyletic group comprises 2 smaller monophyletic groups: the genera Hemiculterella + Pseudohemiculter + Hainania and the genera Hemiculter + Paralaubuca + Pseudolaubuca + Toxabramis. (2) The sister groups of the monophyletic group show both overlapping and vicariant distribution patterns; therefore the generic distribution pattern of the monophyletic group maybe have resulted from both dispersal and vicariance events. (3) The monophyletic group probably originated on the Asian mainland from the Yangtze River to the Pearl River and on Hainan Island in China. (4) The monophyletic group probably originated after the Japanese Archipelago was separated from the Asian mainland at the beginning of the Quaternary Period in the Cenozoic but before Taiwan, Hainan Island, and Indonesia were completely isolated from the Asian mainland after the ice age in the Quaternary Period. (5) Speciation of the genus Hemiculter should have been the earliest, and those of the genera Paralaubuca, Pseudolaubuca, and Hainania ought to be the latest in the process of evolution of this monophyletic group. http://www.sinica.edu.tw/zool/zoolstud/42.1/73.pdf.