Patricia Almeida Sacramento

Fishes from first order streams of lower Paranapanema and Ivaí rivers, upper Paraná River basin, Paraná, Brazil

This study was developed as a research of first order streams fish assemblages located in two Conservation Units in Northwestern Parana, Brazil, with the purpose of providing information about ichthyofauna composition of these water bodies while they are still under protection. There were captured 2,557 individuals belonging to six orders, nine families and 10 species in three streams. The most abundant species were Phalloceros harpagos (44%) from Conceicao stream, Astyanax aff. paranae (14%) and P. harpagos (12%) from Jurema stream, and Melanorivulus apiamici (9%) from Conceicao stream. Trichomycterus sp. could not be identified into a specific level, meaning it can represent an undescribed species to science, registered for the first time at the upper Parana River basin.

Diet-tissue discrimination factors (Δ13C and Δ15N) and turnover rate in somatic tissues of a neotropical detritivorous fish on C3 and C4 diets

In this study, diet-tissue discrimination factors and turnover rates were determined from the somatic tissues of a detritivorous fish Prochilodus lineatus. The carbon (Δ(13) C) and nitrogen (Δ(15) N) diet-tissue discrimination factors varied for all feed rations with a range of Δ(13) C values between -1·9 and 3·6‰ and Δ(15) N between 3·3 and 5·7‰. Carbon turnover rate in the blood was 23·1 days for the C3 ration and 34·7 days for the C4 ration, in the liver was 9·9 days under the C3 ration and nitrogen turnover rate was the same (23·1 days) in the liver for both C4 and C3 -C4 rations, and 13·9 days in the muscle for C3 -C4 ration.

DYNAMICS OF LEAF FALL FROM RIPARIAN VEGETATION AND THE ACCUMULATION IN BENTHIC STOCK IN NEOTROPICAL STREAMS1

Considerando a importância de folhas da vegetacao riparia como fonte energetica para riachos de pequeno porte, este estudo teve por objetivo avaliar a contribuicao de biomassa de folhas para o sistema e a dinâmica de aporte temporal. Para tanto, amostras mensais de julho de 2008 a junho de 2009 foram coletadas utilizando quatro amostradores instalados em tres riachos, a fim de coletar os aportes vertical, lateral e terrestre e o estoque bentonico. Foram testadas as hipoteses de que: (1) o aporte de biomassa de folhas e maior apos periodos de estresse hidrico; e (2) a biomassa do estoque bentonico aumenta com o incremento dos aportes lateral e vertical. As folhas representaram, em media, 71,9% de todo o material aloctone amostrado, com variacao sazonal significativa ao longo do ano. Os picos de entrada de folhas foram registrados em setembro-outubro, apos um periodo de aumento na pluviosidade, e tambem em janeiro, apos decrescimo na pluviosidade. A maior entrada de folhas se deu pelo aporte lateral.

Caloric content of leaves of five tree species from the riparian vegetation in a forest fragment from South Brazil

Abstract Aim: The measurement of the caloric content evidences the amount of energy that remains in the leaf and that can be released to the aquatic trophic chain. We assessed the energy content of leaves from five riparian tree species of a forest fragment in south Brazil and analyzed whether leaf caloric content varied between leaf species and between seasons (dry and wet). The studied sites are located in Northwest of Parana State, inside a Semi-Deciduous Forest fragment beside two headwater streams. Methods Sampling sites were located along the riparian vegetation of these two water bodies, and due to its proximity and absence of statistical differences of caloric values, analyzed as one compartment. Results Caloric content varied significantly among species and among all pairs of species, with exception of Nectandra cuspidata Ness and Calophyllum brasiliensis Cambess. Two species presented significant differences between seasons, Sloanea guianensis (Aubl.) Ben and Calophyllum brasiliensis Cambess. Conclusions The absence of significant seasonal differences of energy content for some species may be due to the characteristics of the tropical forest, in which temperature did not varied dramatically between seasons. However, the energy differed between species and seasons for some species, emphasizing the necessity of a preliminary inspection of energy content, before tracing energy fluxes instead of using a single value to all species from riparian vegetation.