A new species of Boehlkea (Characiformes: Characidae: Stevardiinae) from the rio Japurá, Amazon basin, Brazil

ABSTRACT A new species of Boehlkea is described from rio Japurá, Amazon basin. The new species differs from B. fredcochui by the presence of a vertically elongate humeral spot (vs. absence), complete lateral line (vs. incomplete), four rows of scales below lateral line (vs. three), and lower number of branched anal-fin rays (17-21 vs. 22-25), and from B. orcesi by the higher number of maxillary teeth (13-14 vs. 5-12), greater head length (27.9-29.9% vs. 24.3-27.5% of SL), and by the color pattern (basal half of dorsal-fin, distal portion of pelvic-fin, lower caudal-fin lobe and anal-fin with black chromatophores vs. absence of black chromatophores in the fins)

Mercury levels in birds and small rodents from Las Orquideas National Natural Park, Colombia

Mercury (Hg) is a heavy metal known as one of the most toxic elements on the planet. The importance of Hg on living organisms resides on its biomagnification ability. Artisanal gold extraction activities release substantial amounts of this metal, polluting the ecosystems. To assess the impact of gold mining in Las Orquideas National Natural Park (Colombia), total Hg (T-Hg) levels were evaluated from 37 bird and 8 small rodent species collected at two sites within the boundaries of the Natural Park (Abriaqui and Frontino municipalities) that have experienced some gold-extraction history. The mean concentration of T-Hg in bird feathers from both sites was 0.84 ± 0.05 µg/g fw. Differences between species were found according to diet. Total Hg levels were greater on insectivorous (1.00 ± 0.08 µg/g fw), followed by nectarivorous (0.73 ± 0.07 µg/g fw) and frugivorus (0.57 ± 0.09 µg/g fw) species. These Hg levels were greater than those found in feathers from a control sample belonging to the species Penelope perspicax (0.53 ± 0.03 µg/g fw), a frugivorous species living at the Otun Quimbaya Fauna and Flora Sanctuary, a forest without known gold mining. Mercury concentrations in the livers of small rodents were greater in specimens from Frontino (0.15 ± 0.01 µg/g fw) than those from Abriaqui (0.11 ± 0.01 µg/g fw), but levels were not different between species. These results indicate that Hg in birds depends mainly on their diet, but geographical location may affect Hg concentration in rodents. Moreover, Hg sources in natural parks of Colombia may not rely solely on gold mining, atmospheric deposition, among others factors, could be influencing its accumulation in biota. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature