, DE LOS RIOS ESCALANTE, PATRICIO RENE, Figueroa-Muñoz, Guillermo, Retamal, Marco Antonio, De Los Ríos Escalante, Patricio R., Esse, Carlos, Pérez-Schultheiss, Jorge, Vega-Aguayo, Rolando, Boyero, Luz, Correa-Araneda, F. J.

The marine ecosystem of the Chilean Patagonia is considered structurally and functionally unique, because it is the transition area between the Antarctic climate and the more temperate Pacific region. However, due to its remoteness, there is little information about Patagonian marine biodiversity, which is a problem in the face of the increasing anthropogenic activity in the area. The aim of this study was to analyze community patterns and environmental characteristics of scavenging crustaceans in the Chilean Patagonian Sea, as a basis for comparison with future situations where these organisms may be affected by anthropogenic activities. These organisms play a key ecological role in marine ecosystems and constitute a main food for fish and dolphins, which are recognized as one of the main tourist attractions in the study area. We sampled two sites (Puerto Cisnes bay and Magdalena sound) at four different bathymetric strata, recording a total of 14 taxa that included 7 Decapoda, 5 Amphipoda, 1 Isopoda and 1 Leptostraca. Taxon richness was low, compared to other areas, but similar to other records in the Patagonian region. The crustacean community presented an evident differentiation between the first stratum (0 50 m) and the deepest area in Magdalena sound, mostly influenced by Pseudorchomene sp. and a marked environmental stratification. This species and Isaeopsis sp. are two new records for science. The discovery of undescribed species evidences that this region needs further studies exploring its biodiversity, which is most likely being already impacted by anthropogenic pressure. © 2020 Elsevier B.V., All rights reserved.

, DE LOS RIOS ESCALANTE, PATRICIO RENE, De Los Ríos Escalante, Patricio R., Woelfl, Stefan, Acevedo-Aránguiz, Patricio S., Castro, Manuel

North Patagonian lakes are characterized by their oligotrophic or oligo-mesotrophic status. These conditions bring with them, respectively, the presence of abundant mixotrophic ciliates and a low species number of crustacean zooplankton under oligotrophic status, and low numbers of mixotrophic ciliates and a high species number of zooplankton under oligo-mesotrophic status. The aims of the present study are, (1) to use remote sensing techniques for determining abundances of mixotrophic ciliates and crustacean zooplankton, and (2) to characterize these mixotrophic and zooplankton communities by using null models. The sensing was accomplished from a satellite, i.e., by measuring the reflectance of the sunlight on a waterbody, which result will vary according to the contents of the water column. The results of Principal Component Analysis (PCA) revealed that sites with low reflectance of all bands have a high abundance of Stentor accompanied by low zooplankton absolute abundance, whereas a markedly opposite situation was observed under high reflectance, where Stentor has low abundance in conjunction with high zooplankton absolute abundances. The null models revealed that the communities in the studied sites do not have structured species associations, and that there is an overlap of niches. These results obtained agree with similar observations for Argentinean Patagonian lakes. © 2020 Elsevier B.V., All rights reserved.