This study was developed as a research of first order streams fish assemblages located in two Conservation Units in Northwestern Paraná, 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 Conceição stream, Astyanax aff. paranae (14%) and P. harpagos (12%) from Jurema stream, and Melanorivulus apiamici (9%) from Conceição 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 Paraná River basin.
The aim of this study was to identify the population structure of the ichthyofauna in an urban stream within an environmental protection area in southern Brazil. Quarterly samplings were conducted between October 2009 and August 2010. Poecilia reticulata was the most abundant species, followed by Hypostomus ancistroides and Rhamdia quelen. It was found a higher proportion of adults instead of juveniles from P. reticulata and R. quelen populations, while the opposite was recorded for H. ancistroides. Sex ratio of 1:1 was found for H. ancistroides, but differed significantly for P. reticulata and R. quelen. Females of P. reticulata and R. quelen reached higher length than males in the smaller and higher length-classes, while H. ancistroides females were only longer in initial length-classes. It was recorded higher occurrence of mature and maturing individuals. Mature individuals of H. ancistroides were sampled in October, and P. reticulata and R. quelen throughout the sampling period. Despite adverse environmental conditions, the occurrence of juveniles indicates reproductive activity for these species. Population structure studies in degraded systems are urgent, since life-history features of species may suffer changes due to anthropic impacts. Providing such information contributes to decision making and management of degraded systems.
Conservation Units (CU) aim to contribute to the balance between human and environmental demand, by protecting natural resources and biological communities. In this study we examined the differences in the attributes of the fish community in four stretches of an urban stream, two inside and two outside the CU, without vegetation cover, and tested the hypothesis that the presence of riparian vegetation is positively reflected in the attributes of fish fauna. Five species were caught, distributed into four orders and five families. Attributes like richness, abundance, dominance, Shannon-Wiener diversity, and evenness were estimated and significant differences were detected for continuous stretches considering stream flow direction. The first stretches (URBI and UCI) presented a lower diversity that increased gradually until the last stretch, and an inverse result was found for dominance. These changes occurred regardless the location of the stretch, in-or outside the CU. The importance of Conservation Units within urban areas is severely affected by the lack of continuity of forested areas, especially riparian vegetation. Therefore, we suggest the effective recovery of permanent preservation areas and of riparian vegetation in order to mitigate the impacts of human activities.
A classificação das espécies em guildas tróficas tem sido amplamente utilizada em estudos sobre interações ecológicas. No entanto, o grande número de definições utilizado e a sobreposição de termos têm dificultado a padronização das mesmas para peixes exploradores de fundo. Neste contexto, o presente estudo objetivou quantificar, cienciometricamente, a produção científica envolvendo espécies de peixes exploradores de fundo e as guildas tróficas nas quais elas são classificadas, discutindo, ainda, as definições empregadas. Para tanto, utilizou-se as bases Web of Knowledge e Scopus na análise de publicações quanto a guilda trófica, ano de publicação, país de origem do autor, clima, periódico de publicação, abordagem utilizada, assunto tratado e as definições para as referidas guildas. Constatou incremento no número de publicações a partir de 1990. As regiões com maior número de publicações foram as de clima Tropical e Temperado, com destaque para Estados Unidos, Brasil e Holanda em número de trabalhos publicados. As investigações, principalmente observacionais, foram desenvolvidas, em ambientes de água doce, com foco aos estudos de dieta. Evidenciou-se a ocorrência de diferentes definições para as guildas tróficas dos peixes exploradores de fundo, sendo que os critérios de classificação se basearam, principalmente, no item alimentar e local de alimentação. Em relação aos invertívoros e bentófagos, muitas publicações trazem apenas um dos termos, e o critério de classificação e a descrição dos itens alimentares em ambas as guildas muitas vezes se sobrepõe. O uso da expressão "explorador de fundo" pode ser utilizado quando o objetivo for apenas descrever o local de alimentação dos peixes. Enquanto os termos detritívoro, bentófago, iliófago, invertívoro e comedor de sedimento devem ser utilizados quando referem se especificamente a dieta dos peixes. Palavras-chave: bentófagos; classificação trófica; detritívoros; iliófagos; invertívoros.
This study aimed to characterize the reproductive strategies of fish from first order streams. Samplings were performed every three months from June 2008 to March 2009, using electric fishing at three streams: Conceição, Scherer and Jurema, located in the municipalities of Diamante do Norte and Amaporã, Paraná State, Brazil. We obtained the total weight (g), standard or total length (cm), sex and maturation stage for each specimen. Limnological data were obtained with portable equipments. The minimum length at first maturation was established for each population, and reproduction period was determined by analyzing the distribution of maturation stages. The sex ratio was obtained and tested (X 2) for significant differences. Eight species were analyzed and they responded differently to environmental pressures, reflected in the ratio between males and females, and in different reproductive strategies adopted. The streams were used as spawning ground in September and rest and recruitment areas in December and March, due to changes in the limnological parameters that signalize favorable periods for reproduction. We conclude that the protection provided by preserved riparian vegetation encourage the uptake of food by fishes and maintain their general physical characteristics, promoting the diversification in tactics found.
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