Chironomidae as indicators of water pollution in Pesquería River (México)

Despite their potential as indicators of water quality and key role in river ecosystems, Chironomidae is still poorly studied Neotropical rivers. This lack knowledge especially relevant for rivers subjected to intense human activities, such many Mexico. The aim this investigation contribute the midges Pesquería River (Mexico) along its main courses relate composition abundance health. Thirty samples were collected during two different periods (August 2015 February 2016) using a D-frame kick sampling. Thirty-five taxa found total, with four more than 50% sites 19 only once. Midges accounted total macroinvertebrate abundance. Chironomus gr. plumosus, Rheotanytarsus spp. Cricotopus bicinctus most abundant species. Collector-gatherers dominated August (71% individuals), whereas collector-filterers (43,2%). major factor explaining midge distribution pollution, while structure riparian area does not explain much richness. likely related organic pollution coming from untreated or treated sewage city Monterrey surroundings. Three sectors are distinguished river: i) upper part section higher biodiversity presence intolerant taxa; ii) middle polluted large red very tolerant (Chironomus, Dicrotendipes); iii) lower agricultural zone where community by red, small (Rheotanytarsus). Overall, our study shows that can be useful better when genera species levels used instead family subfamily, usually papers on pollution.