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| Baumgartner,Gilmar; Nakatani,Keshiyu; Gomes,Luiz Carlos; Bialetzki,Andréa; Sanches,Paulo Vanderlei; Makrakis,Maristela Cavicchioli. |
| The purpose of this study was to evaluate the role of abiotic factors on fish larvae occurrence. Samplings were carried out monthly at 12 stations (grouped in four areas) in the Amambaí, Ivaí and Paraná rivers and in the Itaipu Reservoir (upper Paraná River basin), from October 1994 to January 1995 (spawning season). Simultaneously, we obtained water temperature, pH, electrical conductivity, dissolved oxygen, water level, water velocity, and rainfall. Principal Component Analyses (PCA) and Detrended Correspondence Analyses (DCA) were applied to summarize abiotic and larvae density data, respectively. Amambaí River differed significantly from the other areas in relation to abiotic factors. Itaipu Reservoir differed significantly from the other areas... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Larval ecology; Spatial distribution; Floodplain; Itaipu reservoir; Larval drift. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252008000400002 |
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| Nakatani,Keshiyu; Baumgartner,Gilmar; Baumgartner,Maria do Socorro T. |
| The aim of the present study was to characterize the larval development of Plagioscion squamosissimus (Heckel, 1840) morphometrically, collected at Itaipu reservoir from March 1988 to April 1990. It was obtained the samples monthly, with a conic-cylindrical plankton net with 0.5mm mesh. The morphological description of the larvae of P. squamosissimus was based on different stages of development. The specimens less than 6mm long present a moderate sized head and those that are larger than this length, present a large head. The pectoral fins are in an elevated position, near the operculum bones, and the ventral fins are in thoracic positions, the body has a moderate height, the eyes are small to moderate and the mouth is large with caniniform teeth. This... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Plagioscion squamosissimus; Fish larvae; Morphology; Larval development; Itaipu. |
| Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81751997000100003 |
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| Bialetzki,Andréa; Nakatani,Keshiyu; Baumgartner,Gilmar; Bond-Buckup,Georgina. |
| Studies on the occurrence, temporal distribution and nychthemeral variation of Macrobrachium amazonicum (Heller, 1862) were undertaken in Leopoldo's Inlet, upper Paraná River, Porto Rico, Paraná, Brazil. Seventeen thousand and sixty specimens (11,786 larvae and 5,274 juveniles) were captured with a conicalcylindrical plankton net of mesh 0.5mm in monthly samples between February 1991 and February 1992. Results show that the greatest densities of larvae (301.83 larvae/10m³) and juveniles (168.8/10m³) of this species were caught in December 1991. Largest captures were made during the night. With regard to abiotic factors water temperature ranged from 20º to 30ºC, pH ranged from 5.66 to 7.37 and electric conductivity ranged from 51.83 to 65.33µS/cm.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Decapoda; Palaemonidae; Macrobrachium amazonicum; Temporal distribution; Nychthemeral variation; Paraná River. |
| Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81751997000200011 |
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| Baumgartner,Gilmar; Nakatani,Keshiyu; Cavicchioli,Maristela; Baumgartner,Maria do Socorro Tenório. |
| The spatial and temporal distribution and nychthemeral variation of fish larvae in six stations (Ivinhema, Patos, Paraná, Cortado, Baía and Guaraná) in the floodplain of the high Paraná river are provided. The paper also provides the relationship of this distribution to some environmental factors. From March 1992 to February 1993 ichthyoplanktonic samples were collected by conic cylindrical nets, with 0.5mm of mesh size and fluxometer attached, in 10-minute hauls at the surface and bottom during nychthemeral cycles. At the same time water samples were taken to determine environmental factors. During the above period 5,672 larvae were collected: 57,6% from Cortado station and 13,2% from Ivinhema and Paraná stations. The greatest densities were recorded... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fish larvae; Ecology; Distribution; Floodplain; Paraná river. |
| Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81751997000300005 |
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| Bialetzki,Andréa; Sanches,Paulo Vanderlei; Baumgartner,Gilmar; Nakatani,Keshiyu. |
| With the purpose of characterizing morphologicaly the larvae and juveniles of Apareiodon affinis (Steindachner, 1879) and to verify their temporal distribution monthly samples were taken at Leopoldo's Inlet, upper Paraná River. The specimens were captured with a conic-cylindrical plankton net of mesh size 0,5mm from March 1991 to February 1992. Soon after identification, the specimens were separeted according to their development (prefle-xion, flexion, posflexion and juvenile) and then the moiphometric analyses were performed. The results showed that the larvae were captured from August 1991 to February 1992, with greatest densities in November 1991. The specimens occured in every timetable, however, larvae in pretlexion and flexion were captured during... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Apareiodon affinis; Morphological development; Temporal distribution; Upper Paraná River. |
| Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81751998000400021 |
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| Bialetzki,Andréa; Sanches,Paulo Vanderlei; Cavicchioli,Maristela; Baumgartner,Gilmar; Ribeiro,Ricardo Pereira; Nakatani,Keshiyu. |
| Analysis of drift of ichthyoplankton in two channels in the River Paraná, Brazil, were made. Sampling was undertaken from October 1995 to April 1996 during nychthemeral cycles. Water samples were collected to determine several environmental variables. Eggs densities largely differed to layers, times of day and months. In both the channels, highest occurrence of eggs was detected between January and March; greater concentrations at the bottom, during night. With regard to larvae, densities were significantly different in channels, times of days and months. Maximum occurrences were seen in the right channel, in both layers, with largest capture between January and March. Surface of the both channels presented highest density of larvae during night. Water... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Drift; Ichthyoplankton; Paraná River. |
| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89131999000100008 |
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