Checklist comparison and dominance patterns of the fish fauna at Taim Wetland, South Brazil

Alex Moresco,Alexandre M Garcia,David M L Motta Marques,João P Vieira,Marlise A Bemvenuti,Marcelo D M Burns,Mario Vinicius L Condini

doi:10.1590/s1679-62252006000200012

Alex Moresco, Alexandre M Garcia + Show 5 more

Open Access

https://doi.org/10.1590/s1679-62252006000200012

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Abstract

Taim Hydrological System is a unique subtropical wetland in southern Brazil harboring an exceptional biological diversity. In 1978, an ecological reserve was established to protect part of this area from increasing anthropogenic impacts in its surroundings. Fishes have been poorly investigated in this system. Based on a multi-gear sampling study encompassing several years (2001-2005), and on comparisons with previous fish inventories, we provide an up-to-date species list of fishes occurring in the Taim Wetland. In addition, we made the first preliminary description of fish dominance patterns found in the main lakes of the system (Flores, Nicola, Jacaré and Mangueira). Checklist comparison resulted in 62 fish species distributed in 24 families, with Characidae (19 species) and Cichlidae (7) showing the highest species richness. Six species are cited for the first time in the reserve: Trachelyopterus lucenai (Auchenipteridae), Hoplosternum littorale (Callichthyidae), Rineloricaria cadeae (Loricariidae), Eigenmannia trilineata (Sternopygidae), Odontesthes mirinensis and O. perugiae (Atherinopsidae). Apparently, the black catfish T. lucenai invaded the system in the last decade and became one of the dominant species in the pelagic waters. Although differences in gears hindered direct comparisons, differences in species composition and dominance patterns between shallow margins and pelagic waters of lakes seem to occur in the lakes. A more diverse assemblage dominated by small fishes (< 5cm) occurred in the protected, vegetated lakes margins. In contrast, an assemblage with lower species richness comprised of larger fishes (> 15 cm) seemed to dominate in pelagic waters.

Highlights

Taim Hydrological System is a unique freshwater wetland ecosystem in southern Brazil encompassing a variety of habitats such as beaches, dunes, forests, grasslands and, especially, lakes and wetlands
Checklist comparison resulted in 62 fish species occurring at Taim Wetland distributed in 24 families, with Characidae (19 species) and Cichlidae (7) showing the highest species richness (Table 1)
Six species were recorded for the first time in the study area: Trachelyopterus lucenai (Auchenipteridae), Hoplosternum littorale (Callichthyidae), Rineloricaria cadeae (Loricariidae), Eigenmannia trilineata (Sternopygidae), Odontesthes mirinensis and O. perugiae (Atherinopsidae)

Summary

Introduction

Taim Hydrological System is a unique freshwater wetland ecosystem in southern Brazil encompassing a variety of habitats such as beaches, dunes, forests, grasslands and, especially, lakes and wetlands Such heterogeneous and productive landscape harbors an exceptional biological diversity, which, in part, motivated Brazilian federal authorities to consider part of this hydrological system as the Taim Ecological Reserve in 1978 (Motta Marques et al, 2002). Such conservation status has been crucial in protecting this area from increasing anthropogenic impacts in its surroundings, such as water diversion for rice irrigation and fishing activities. Fishes usually represent an important biological component in freshwater wetlands, playing crucial roles in energy flow between lower and higher trophic levels (DeAngelis et al, 2005), in top-down controls via predation (Carpenter, 1985), as important groups sustaining high biological diversity

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