ABSTRACT. Temporal changes in the abundance and diversity of the fish fauna in the shallow infralittoral of a beach, southern Brazil. Abundance and diversity of the fish fauna in the shallow infralittoral region of Atami Beach, Paraná, Brazil, were studied through monthly collections between July 1998 and June 1999. A total of 7553 fishes from 70 species and 26 families, mainly juvenile forms, was captured in the area. The mean captures in number of species, number of fish and biomass were larger from the end of spring to the middle of autumn; seasonal tendency in richness, diversity (number) and equitability indices were not observed. The largest mean dissimilarity in the composition of the ichthyofauna occurred between June and May in comparison to the period between July and October. The species that contributed most to this dissimilarity were Selene setapinnis (Mitchill, 1815), Conodon nobilis (Linnaeus, 1758) and Stellifer rastrifer (Jordan, 1889). Three great groups reflecting patterns of temporal occurrence of the most abundant species were identified.

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Annual variation in the fish assemblage characteristics on a tidal flat was studied in coastal Paraná, in southern Brazil. Fish were collected between August 1998 and July 1999, during the diurnal high tide and diurnal and nocturnal low tide of the syzygial (full moon) and quadrature (waning moon) tides, to characterize temporal change in assemblage composition. A total of 64,265 fish in 133 species were collected. The average number of species and individuals, biomass, species richness, diversity (mass) and equitability varied significantly over time . The dissimilarity of the assemblage was greatest in August, September and October in contrast with the period from November to January, with the lowest dissimilarity. The combined action of water temperature, salinity and wind intensity had a great influence over the structure of the fish assemblage.
Os peixes de uma planície de maré da praia Balneário de Pontal do Sul, Paraná, foram coletados, na preamar diurna e na baixa-mar diurna e noturna das marés de sizígia e de quadratura, visando caracterizar as mudanças temporais entre agosto de 1998 e julho de 1999. As coletas totalizaram 64.265 peixes de 133 espécies. Foram observadas diferenças significativas na captura média em número de espécies e de peixes, peso total e nos índices de riqueza, diversidade (H' peso) e eqüitatividade entre os meses de coleta. A dissimilaridade da ictiofauna foi maior entre os meses de agosto, setembro e outubro em comparação com o período de novembro a janeiro. A ação combinada da temperatura da água, salinidade e intensidade do vento, influenciaram mais sobre a estrutura da assembléia de peixes

ABSTRACT. Fishes were sampled by beach seine during the day and night at the high and low sygygy tides, on asandy beach at the southeast coast ofBrazil. The quantitative results appear to indicate a larger concentration of fish in the surf zone of this beach, in low tides at the start and end of the day. Only eight from the 17 most abundant taxa, appeared to have been influenced singly or in combination by the factors ofthe moon, day, night and tide.

Despite its importance, most ichthyoplankton studies in the South

The fish assemblage in a mangrove tidal creek was studied in monthly collections between August 1998 and July 1999 in the quadrature low tide and high tide, using a fyke net of 30 m x 1.5 m and meshes of 8 and 10 mm. Simultaneously with the biological collections, temperature, salinity, pH, water transparency, and current speed data were obtained. The collections resulted in the capture of 36,873 fish representing 22 families and 52 species. Immature individuals abounded (63.8%), and among the adult specimens there was a larger number of females. The species Anchoa parva, Harengula clupeola, Genidens genidens, and Bairdiella ronchus, contributed to 84.9% of the total capture of fish, however the contribution in mass was of 55.2%, indicating a predominance of small individuals. A smaller number of fish and species seem to occupy the area in the period between August and December, in comparison to the period between February and July, when the larger aggregations appear, mainly of the species Anchoa parva, Harengula clupeola, Opisthonema oglinum, Genidens genidens, Diapterus rhombeus, and Bairdiella ronchus. The environmental factors, pH, water transparency, and rainfall seem to have an influence in the structure of the observed biological patterns.Key words: tidal creek, fishes, diversity, abundance, temporal variation. RESUMO Um estudo sobre a estrutura da comunidade de peixes de um rio de maréA comunidade de peixes em um rio de maré de mangue foi estudada em coletas mensais entre agosto de 1998 e julho de 1999 na baixa-mar e preamar de quadratura, utilizando-se uma rede fixa tipo "fyke" com 30 m x 1,5 m e malhas de 8 e 10 mm. Simultaneamente às coletas biológicas, foram registrados dados de temperatura, salinidade, pH, transparência da água e velocidade da corrente. As coletas resultaram na captura de 36.873 peixes, representando 22 famílias e 52 espécies. Predominaram indivíduos imaturos (63,8%) e as fêmeas, entre os adultos. As espécies Anchoa parva, Harengula clupeola, Genidens genidens e Bairdiella ronchus constituíram 84,9% da captura total de peixes, no entanto, a participação em peso foi de 55,2%, indicando o predomínio de indivíduos de pequeno porte. Um menor número de peixes e espécies parece ocupar a área no período entre agosto e dezembro, comparado ao período entre fevereiro e julho, quando aparecem os maiores agregados, principalmente das espécies Anchoa parva, Harengula clupeola, Opisthonema oglinum, Genidens genidens, Diapterus rhombeus e Bairdiella ronchus. O pH, a transparência da água e a pluviosidade parecem influenciar a estruturação dos padrões biológicos observados.Palavras-chave: rios de maré, peixes, diversidade, abundância, variabilidade temporal.

ABSTRACT. A total of6,575 larvae in the pre flexion, flexion and post-flexion stages of 15 families, 26 genera and 29 species were captured in the surf zone of Pontal do Sui beach, Parana, Brazil. Samples of the families Gerreidae and Scianidae predominated and larvae of Eucinostomus argenteus (Baird&Girard, 1854) (Agassiz, 1829) were the most dominant species. Greater abundance of larvae was observed during the summer, followed by winter and in a less extent during spring and autumn. The number of species was greater in the summer, and there were no significant differences in the rest of the seasons.

The planet Earth is made up of a large percentage of water, being only 3% of fresh water. Of this fresh water, approximately 0.3% is available to be used by the planet's inhabitants. For the evaluation of the health conditions of the water, bacteria of the coliform group are use, being their presence in the aquatic environment a potential indicative of pollution, as well as of the risk for presence of pathogenic organisms. Brazil has the highest availability of water on the planet, but in several parts of the country, many rivers are polluted. The objective of the study was to perform the microbiological analysis of the Bacacheri River water, located in the city of Curitiba, Paraná, which is included in the section of fresh waters, aimed at preserving the natural balance of aquatic communities, in order to determine the level of pollution in five pre-determined points, following the growth of colonies of fecal coliforms and total coliforms, through the membrane filter technique. The results show proliferation of fecal and total coliforms in values above the limit proposed by CONAMA no. 357/2005 Brazilian determination in all harvest points observed. In addition, points # P1, # P2, and # P5 are the most affected ones, whereas points # P3 and # P4 seem to be less affected, probably due to the presence of ciliary forest, as well as the channeling of the banks and the bottom of the river.