Ecological Indicators 75 (2017) 279–285 Contents lists available at ScienceDirect Ecological Indicators j o ur na l ho me page: www.elsevier.com/locate/ecolind Original Articles Invasive bivalves increase benthic communities complexity in neotropical reservoirs Marden Seabra Linares a,∗,1 , Marcos Callisto a,1 , João Carlos Marques b a Laboratório de Ecologia de Bentos, Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, CP 486, CEP31270-901 Belo Horizonte, MG, Brazil b MARE-Marine and Environmental Sciences Centre, Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, Portugal a r t i c l e i n f o Article history: Received 19 September 2016 Received in revised form 23 December 2016 Accepted 27 December 2016 Keywords: Eco-exergy Ecosystem engineers Invasive species Thermodynamic ecological indicators a b s t r a c t Invasive bivalves often act as ecosystem engineers, generally causing physical alterations in the ecosys- tems in which they establish themselves. However, the effects of these physical alterations over benthic macroinvertebrate communities’ structure are less clear. The objective of this study was to characterize the ecological effects of the invasive bivalves Corbicula fluminea and Limnoperna fortunei on the structure of benthic macroinvertebrate communities in neo-tropical reservoirs. Three hypotheses were tested: (1) invasive bivalves act as facilitator species to other benthic macroinvertebrates, resulting in communities with higher number of species, abundance and diversity; (2) invasive bivalves change the taxonomic composition of benthic macroinvertebrate communities; (3) invasive bivalves increase the complex- ity of benthic macroinvertebrate communities. For that it was used data from 160 sampling sites from four reservoirs. We sampled sites once in each area, during the dry season from 2009 to 2012. The first hypothesis was rejected, as the presence of invasive bivalves significantly decreased the host ben- thic communities’ number of species and abundance. The second hypothesis was corroborated, as the composition of other benthic macroinvertebrates was shown to be significantly different between sites with and without invasive bivalves. We observed a shift from communities dominated by common soft substrate taxa, such as Chironomidae and Oligochaeta, to communities dominated by the invasive Gas- tropoda Melanoides tuberculata. The biomass data corroborated that, showing significantly higher biomass of M. tuberculata in sites with invasive bivalves, but significantly lower biomass of native species. Benthic macroinvertebrate communities presenting invasive bivalves showed significantly higher eco-exergy and specific eco-exergy, which corroborate the third hypothesis. These results suggest that while the presence of invasive bivalves limits the abundance of soft bottom taxa such as Chironomidae and Oligochaeta, it enhances benthic communities’ complexity and provide new energetic pathways to benthic communities in reservoirs. This study also suggests a scenario of invasion meltdown, as M. tuberculata was facilitated by the invasive bivalves. © 2016 Published by Elsevier Ltd. 1. Introduction Invasive species are considered the second highest cause of bio- diversity loss at a global scale (Ricciardi, 2007; Thomaz et al., 2015; Vitousek, 1997). Freshwater ecosystems are especially vulnerable, due to widespread human disturbance, such as channelization, pol- lution and dam and reservoir construction (Havel et al., 2005; Turak et al., 2016). ∗ Corresponding author. E-mail addresses: mslx@hotmail.com (M.S. Linares), callistom@ufmg.br (M. Callisto), jcmimar@ci.uc.pt (J.C. Marques). 1 http://lebufmg.wixsite.com/bentos Invasive bivalves are among the most successful invasive species in freshwater ecosystems (Oliveira et al., 2011; Paschoal et al., 2015; Ricciardi, 2007). As most successful invasive species, inva- sive bivalves are typically r-selected species, adapted to colonize a wide range of aquatic environments and exhibiting high fecundity, rapid growth and broad physiological tolerance to several abiotic factors (Nakano et al., 2015). Such characteristics allow them to become dominant species, exhibiting high densities and constitut- ing a major fraction of the benthic macroinvertebrates community biomass (Karatayev et al., 2007b). Most of the impacts on benthic communities caused by invasive bivalves are a direct result on their function as ecosystem engi- neers, which cause environmental physical modifications (Jones et al., 1994; Sousa et al., 2009 Zaiko and Daunys, 2015). Actually, bivalve shell production, filter feeding and bioturbation, result in http://dx.doi.org/10.1016/j.ecolind.2016.12.046 1470-160X/© 2016 Published by Elsevier Ltd.