The lab’s latest Ph.D. candidate, Diego Simeone Ferreira da Silva, submitted his thesis in April 2021 and was recently approved, obtaining an average grade of 9.75 (Excellent). Congratulations, Diego! The examining committee members were Daniel Pereira (Lótica P&D Consultoria Ambiental, Rio Grande do Sul), Igor Christo Miyahira (Universidade Federal do Estado do Rio de Janeiro, Rio de Janeiro), Cleidson Paiva Gomes (Federal Institute of Pará) and Marcus E. B. Fernandes (Federal University of Pará).

Diego’s thesis is an extension of his Master’s Dissertation, published in Freshwater Biology that looked at freshwater mussels and other invertebrates in meander habitats in the Caeté river. In his Ph.D., Diego investigated the freshwater mussels Castalia ambigua and Anodontites elongatus in a more diverse range of habitats, using various complex hydraulic variables to characterize the habitat. Diego’s thesis is divided into four main research topics, integrated by an introductory chapter and concluding remarks. The first topic deals with the ecological functions associated with freshwater mussels (filtration and biodeposition) and their influence on macroinvertebrate abundance and diversity, and habitat functioning, now published in Hydrobiologia. The second topic looks at the effect of mussel density on the abundance and diversity of other associated macroinvertebrates, and habitat quality, by comparing exploited and non-exploited mussel beds that differ in density, and is available online in Ecological Indicators. The third topic relates to the occurrence and longitudinal distribution of Castalia ambigua and Anodontites elongatus associated with hydraulic variables, and the effect of landscape modifications on the density of these two mussel species at the sub-catchment and riparian buffer spatial scales, currently submitted to Ecology and Evolution. The fourth topic investigates patterns in the shape of the shell of Castalia ambigua associated with a longitudinal gradient in hydraulic energy, using elliptical Fourier analysis, and is currently in preparation for submission.

Diego’s work is helping to draw more attention to the importance of freshwater mussels and the benefits of their interactions with other aquatic organisms and habitat in Brazil. Diego will certainly continue to investigate diversity and function in freshwater mussels, and we are hoping to upscale his work in order to rapidly evaluate suitable habitat and prioritize conservation efforts in rivers in the eastern Amazon region and beyond.