Tupinambás T H, Pompeu P S, Gandini C V, Hughes R M, Callisto M
Departamento de Biologia Geral, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
Departamento de Biologia, Universidade Federal de Lavras, Lavras, MG, Brazil.
Braz J Biol. 2015 Jan-Mar;75(1):157-64. doi: 10.1590/1519-6984.09913.
The choice of sampling gears to assess benthic macroinvertebrate communities depends on environmental characteristics, study objectives, and cost effectiveness. Because of the high foraging capacity and diverse habitats and behaviors of benthophagous fishes, their stomach contents may offer a useful sampling tool in studies of benthic macroinvertebrates, especially in large, deep, fast rivers that are difficult to sample with traditional sediment sampling gear. Our objective was to compare the benthic macroinvertebrate communities sampled from sediments with those sampled from fish stomachs. We collected benthic macroinvertebrates and fish from three different habitat types (backwater, beach, riffle) in the wet season, drying season, and dry season along a single reach of the Grande River (Paraná River Basin, southeast Brazil). We sampled sediments through use of a Petersen dredge (total of 216 grabs) and used gill nets to sample fish (total of 36 samples). We analyzed the stomach contents of three commonly occurring benthophagous fish species (Eigenmannia virescens, Iheringichthys labrosus, Leporinus amblyrhynchus). Chironomids dominated in both sampling methods. Macroinvertebrate taxonomic composition and abundances from fish stomachs differed from those from sediment samples, but less so from riffles than from backwater and beach habitats. Macroinvertebrate taxa from E. virescens stomachs were more strongly correlated with sediment samples from all three habitats than were those from the other two species. The species accumulation curves and higher mean dispersion values, compared with with sediment samples suggest that E. virescens is more efficient than sediment samples and the other fish studied at collecting benthic taxa. We conclude that by analyzing the stomach contents of benthophagous fishes it is possible to assess important characteristics of benthic communities (dispersion, taxonomic composition and diversity). This is especially true for studies that only sample fish assemblages to evaluate aquatic ecosystem impacts. Therefore, this approach can be useful to amplify assessments of human impacts, and to incorporate additional bioindicators.
选择用于评估底栖大型无脊椎动物群落的采样工具取决于环境特征、研究目标和成本效益。由于食底栖生物鱼类的觅食能力强、栖息地多样且行为各异，它们的胃内容物可能为底栖大型无脊椎动物研究提供一种有用的采样工具，尤其是在难以用传统沉积物采样工具进行采样的大型、深水、湍急河流中。我们的目标是比较从沉积物中采样的底栖大型无脊椎动物群落与从鱼胃中采样的群落。我们在巴西东南部巴拉那河流域格兰德河的一个河段，于雨季、枯水期和旱季从三种不同的栖息地类型（回水湾、海滩、浅滩）采集了底栖大型无脊椎动物和鱼类。我们使用彼得森采泥器对沉积物进行采样（共采集216次），并用刺网对鱼类进行采样（共采集36个样本）。我们分析了三种常见食底栖生物鱼类（绿 Eigenmannia virescens、唇须鲇 Iheringichthys labrosus、钝吻兔脂鲤 Leporinus amblyrhynchus）的胃内容物。在两种采样方法中，摇蚊科均占主导地位。鱼胃中的大型无脊椎动物分类组成和丰度与沉积物样本不同，但与浅滩栖息地相比，与回水湾和海滩栖息地的差异较小相比，来自 Eigenmannia virescens 胃中的大型无脊椎动物分类单元与所有三种栖息地的沉积物样本的相关性比来自其他两种鱼类的更强。与沉积物样本相比，物种积累曲线和更高的平均离散值表明，Eigenmannia virescens 在收集底栖分类单元方面比沉积物样本和其他研究的鱼类更有效。我们得出结论，通过分析食底栖生物鱼类的胃内容物，可以评估底栖群落的重要特征（离散度、分类组成和多样性）。对于仅对鱼类群落进行采样以评估水生生态系统影响的研究尤其如此。因此，这种方法有助于扩大对人类影响的评估，并纳入额外的生物指标。
