RESUMEN La pesca de arrastre de camarón afecta directamente a la especie de interes y a otras que no lo son, pero tambien quedan atrapadas, alterando los micro-hábitats y las vías tróficas marinas. Así, el presente estudio tuvo como objetivo analizar los hábitos alimentarios de Paralonchurus brasiliensis, como herramienta para evaluar el impacto de la pesca de arrastre sobre las cadenas alimentarias en ambientes marinos, en el Atlántico sur de Brasil. Se disecaron 1219 estómagos de P. brasiliensis capturados con "bycatch" del camarón Xiphopenaeus kroyeri, en Penha, litoral centro-norte de Santa Catarina, Brasil. El número de estómagos fue suficiente para la descripción de los hábitos alimentarios de P. brasiliensis, caracterizándola como una especie carnívora, predominantemente invertívora. Los resultados revelaron además que esta especie posee una dieta diversificada y constante, con mayor consumo de poliquetas, crustáceos y ofiuroides, entre otros componentes del macrobentos, todos íntimamente relacionados al sedimento. Se constató también que la especie de interes X. kroyeri no es una presa importante en la dieta de P. brasiliensis, a pesar de ocupar el mismo hábitat. De acuerdo con el presente estudio, P. brasiliensis puede ser caracterizada como una especie demersal bentónica, predadora, oportunista y de amplio espectro trófico. Este trabajo contribuye a la comprensión de las cadenas tróficas de los ecosistemas costeros, utilizando el caso de P. brasiliensis como modelo.

ABSTRACT Shrimp trawling directly impacts target species and non-target species, altering micro-habitats and marine trophic webs. Thus, the objective of the present research was to analyze the feeding habits of Paralonchurus brasiliensis as a tool to evaluate the impact of trawling on the food chains in marine environments, in the South Atlantic of Brazil. One thousand and nineteen stomachs of P. brasiliensis were dissected after being captured as bycatch of shrimp Xiphopenaeus kroyeri, in Penha, on the north central coast of Santa Catarina, Brazil. The number of stomachs was enough to describe the feeding habits of P. brasiliensis, characterizing it as a carnivorous species and predominantly invertivorous. They also revealed that this species has a diversified and constant diet, with greater consumption of polychaetes, crustaceans, and ofiuroides, among other components of the macrobentos, all closely related to the sediment. It was also found that the target species X. kroyeri is not an important prey in the diet of P. brasiliensis, despite occupying the same habitat. According to the present study, P. brasiliensis can be characterized as a demersal-benthic species, predator, opportunistic and broad trophic spectrum. This work contributes to the understanding of trophic chains of the coastal ecosystems, using the P. brasiliensis as a model.

Abstract Bathygobius soporator (popularly known as “Maria da toca”) is a species that, although abundant, is little studied in aspects regarding growth, feeding and reproduction in southern Brazil. Studies on trophic ecology still raise questions on the species’ actual diet, especially in the context of algae participating as a food resource or an accidental intake. Thus, this study aims to fill this gap, evaluating the growth, feeding, and reproduction of this species. Monthly samples from two periods (1997-1998 and 2005-2006) were analyzed for growth, feeding, and reproduction parameters, totalizing 1177 individuals evaluated. Our results demonstrate that Bathygobius soporator is a species of fast development, reaching the age of first maturation before the first year of life. It presents a sexual dimorphism, being males larger than females. Reproductive peaks occur in the spring and summer months. The species presented a broad trophic spectrum, including algae as the main food resource, not just an accidental intake. The omnivorous-opportunistic trophic ecology of this species is emphasized, agreeing with the information of previous studies.

Abstract The Land uses and occupations around small watersheds generate negative impacts such as deterioration of water quality, environmental simplification, reduced availability of habitats for species, and loss of biodiversity. Benthic macroinvertebrates are an important aquatic community and are widely used in environmental monitoring actions in aquatic ecosystems, including urban streams, which are still little studied in Brazil. In our study, an urban headwater basin (Monjolinho River Basin) was studied on the benthic community structure, together with the physical and chemical variables of the water, as an environmental monitoring tool calculated by RHDEP, TSI, BMWP indexes and abundance-biomass curves. The results showed a gradient of environmental quality, where the best environments are a consequence of preserving the vegetation cover. These environments (Espraiado and Canchim) present groups sensitive to environmental degradation (Ephemeroptera, Plecoptera and Trichoptera), greater diversity and a better structure in the respective benthic macroinvertebrate assemblages. Among the streams sampled, one is very clean, four are moderately polluted, and one is severely polluted. Thus, considering that these streams’ waters are essential for public supply, actions to clean up and recover degraded environments are urgent and a priority.

Os fatores de condição relativo (Kn) de Astyanax paranae, Phalloceros harpagos e Poecilia reticulata foram utilizados como ferramenta para avaliar a influência da qualidade ambiental sobre o bem estar de sub-populações destas espécies, visando utilizá-las como bioindicadoras de distúrbios em córregos afluentes do rio Monjolinho, no município de São Carlos - SP. A curva potencial gerada pela relação peso-comprimento indicou um crescimento do tipo alométrico positivo para as três espécies estudadas. No geral, a análise de correspondência canônica (CCA) correlacionou positivamente o Kn médio da espécie A. paranae com ambientes bem oxigenados e oligotróficos, característicos de áreas preservadas ou próximas do estado natural. Para o valor médio do Kn obtido para a espécie Phalloceros harpagos, não ocorreram diferenças significativas entre áreas naturais e perturbadas. Entretanto, a CCA correlacionou positivamente o Kn médio da espécie Poecilia reticulata a ambientes impactados, com maior grau de trofia, o que sugere que o fator de condição relativo desta espécie pode ser utilizado como indicador de distúrbios, neste caso, ocasionado pela poluição orgânica.

The relative condition factors (Kn) of the fishes Astyanax paranae, Phalloceros harpagos and Poecilia reticulata were used as a means of assessing the influence of environmental conditions on the well-being of sub - populations of these species, with the eventual aim of using them as bioindicators of disturbance in tributary streams of the Monjolinho River, in São Carlos - SP. The power-law curve generated by the length-weight relationship indicated a positive allometric growth for the three species studied. Overall, the canonical correspondence analysis (CCA) positively correlated average Kn of A. paranae with well oxygenated and oligotrophic environments, typical of conserved areas or near the natural state. For the average value of Kn obtained for Phalloceros harpagosspecies, there was no significant difference between natural and disturbed areas. However, the CCA positively correlated the mean Kn of the speciesP. reticulata from similar environments with higher trophic level, suggesting that this species is indicative of disturbance.