ESTIMATES OF NON-TANYPODINAE CHIRONOMID PRODUCTION IN THREE NEOTROPICAL HEADWATER STREAMS IN THE BRAZILIAN SAVANNA
Aquatic insects such as midges are important components of freshwater ecosystems. However, measuring their production is difficult due to their short development times and overlapping cohorts. We estimated production of non-Tanypodinae chironomid larvae in three headwater streams in the Brazilian savanna. Biomass was estimated from samples collected between October 2015 – September 2016, and we estimated assemblage-level growth rates (g) using two methods: a published temperature-specific model developed for temperate streams, and direct measurements of individuals placed in growth chambers in streams. For chambers, individual lengths were measured at the beginning, middle (7 days) and end (14 days) of the experiment. When growth values derived from the temperature-specific model and chambers were applied to biomass data, annual production estimates across the three streams ranged from 7.9 - 14.1, and 8.1 - 10.4 g ash-free dry mass m-² y-¹, respectively. Annual production to biomass ratios ranged from 24 - 26 with the temperature-specific model, and 16 - 28 with growth chambers estimates. No statistical difference was found between the two methods. Results suggest that the temperature-specific model developed in temperate streams may be reliably applied to some tropical streams.
José Mello (Primary Presenter/Author), University of São Paulo, firstname.lastname@example.org;
Daniel Abrahão (Co-Presenter/Co-Author), University of São Paulo, email@example.com;
Matt Whiles (Co-Presenter/Co-Author), Southern Illinois University - Carbondale, firstname.lastname@example.org;
Juliano Corbi (Co-Presenter/Co-Author), University of São Paulo, email@example.com;