Geographic range extension of Elachistocleis corumbaensis Piva, Caramaschi & Albuquerque, 2017 (Anura, Microhylidae) with new records in ecotonal zones in the state of Mato Grosso, Brazil

Elachistocleis corumbaensis was documented in 2017 in the central region of the Brazilian Pantanal and no other record of the species has since been reported. In this study, we report on the extension of the geographic range of E. corumbaensis based on 4 new records found in the riparian forests of the Paraguay River, in the state of Mato Grosso. Of these, 1 specimen was collected in a protected area in the Pantanal. We also report on the presence of this species in the ecotones between the Pantanal, Cerrado, and Amazonia, which suggests that E. corumbaensis is associated with seasonally flooded forests but more widely distributed in western Brazil than previously reported

Cyanobacteria as regulators of methylmercury production in periphyton

Biotic mercury (Hg) methylation appears to depend on factors such as microbial activity and the concentration and bioavailability of Hg 2+ to the Hg-methylating organisms. Recently, the presence of cyanobacteria has been linked with high methylmercury (MeHg) concentrations. The aim of this work was to test MeHg production in microcosms, in relation to the amount of periphytic cyanobacteria, dissolved organic matter (DOM) and phosphorus concentrations, as well as periphytic primary production rates. Water and periphyton samples were collected for cultivation and isolation of cyanobacteria from the Guaporé River floodplain, Brazil. We cultivated the periphyton in microcosms with different concentrations of cyanobacteria, total phosphorus and DOM. The highest net MeHg production (6.8 to 24.6% of added Hg d −1 ) occurred in the microcosm with added cyanobacteria, followed by microcosms with added phosphorus (6.1 to 11.4%) and added DOM (6.4 to 9.1%). Positive correlations were found between MeHg production, addition of cyanobacteria, phosphorus and DOM and periphytic primary productivity. Our results bring the first direct experimental evidence of the relevance of cyanobacteria and primary production as regulators of MeHg production in periphyton. These findings have numerous implications for the management of natural and engineered wetlands. © 2019 Elsevier B.V.This work was supported by the Rede Bionorte “Project Biodiversity Conservation, use and bio-prospection in the Meridional Amazon-Mato Grosso, under the auspices of MCTI/CNPq/FAPEMAT, grant n. 554330/2010-5 , CNPq grant n. 205983/2011 , and project CNPq/ INPeTAm . JRDG is a CNPq research fellow and has a CNE FAPERJ grant 202.954/2015.Peer reviewe

Predation record of Rhinella marina (Linnaeus, 1758) (Anura: Bufonidae) by Cerdocyon thous (Carnivora: Canidae) using camera trap in Vale do Paraíso, Rondonia, Brazil

The crab-eating fox (Cerdocyon thous) is a Neotropical canid with a generalist and opportunistic diet that includes a wide variety of food items. On this note, we report the first record of predation on Rhinella marina by Cerdocyon thous in the state of Rondonia, Brazil, based on camera trap footage. For the state of Rondonia, there is no study reporting the prey of C. thous. Therefore, this report approaches important ecological knowledge of the crab-eating fox, portraying behaviors and diet of the species

New insights on the use of bill sheath as a biomonitoring tool for mercury in two kingfisher species: A comparison with different tissues

Bird species have been widely used as suitable bioindicators of environmental mercury (Hg). However, there is still some debate about the most suitable tissue to indicate Hg body burden in birds. For a long time, blood and feathers have proved to be relevant to monitor Hg at different time scales, and recently, bill sheath has been suggested as a potential tissue to this end. In the present study, we evaluated THg in muscle, liver, feathers, claws, and bill sheath in two waterbird species (i.e. the ringed and the Amazon kingfishers) from the Teles Pires, Juruena and Paraguay rivers. Considering all species and sites, feathers (5.47 ± 2.15 μg/g) and bill sheath (3.39 ± 1.37 μg/g) had mean THg concentrations about 2-, 3- and 10-times higher than claws, liver and muscle, respectively. When bird species were segregated, the ringed kingfisher showed THg values 1.8 times higher than the Amazon kingfisher in all tissues. Moreover, results showed that the Amazon kingfisher from the Juruena and Teles Pires rivers was clearly separated from the Paraguay River (control site), and was associated with higher THg values in the claws and feathers. Results obtained for the THg concentrations in bill sheath, muscle and liver tissues of the Amazon kingfisher using multivariate analysis of canonical variates (CVA) showed a pattern of segregation between the sampling areas, being the highest THg values in Teles Pires River samples. The largest bill sheath vector in the CVA suggests that this tissue is a key variable in the segregation of the samples. Overall, feathers may be useful for effects monitoring or spatial patterns, whereas bill sheath, which are more invasive, may be advantejous for temporal trends and retrospective studies of Hg pollution.G. de Medeiros Costa would like to express her gratitude to Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES/Brazil) for a scholarship under the Programa de Doutorado Sanduiche no Exterior (PDSE), file 88881.189396/2018–01. The authors would also like to acknowledge the CYTED (Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo), for financing the MercuRed Network (420RT0007).Peer reviewe

New records amplify the geographical distribution of Rondonops biscutatus Colli et al., 2015 (Squamata, Sauria, Gymnophthalmidae) into the Paraguay river basin, Mato Grosso, Brazil

Rondonops biscutatus is a gymnophthalmid litter-lizard which occurs in the Amazon rainforests and the transitional areas between Amazonia and Cerrado. This species’ distribution is strongly biased by a lack of data, possibly because it was recently described, small-bodied, and living in cryptic habits. Here, we present occurrence data of six specimens from four locations in transitional areas between forests in Amazonia and Cerrado (central Brazil), in the upper Paraguay River, at the northern end of the Pantanal, midwestern Brazil. We expand the distribution of this species 507 km east from its original range.