Abstract The Cautin river is located in the 137 years old Araucania region, Chile (38°S), and is characterized by alterations through human interference due agriculture and towns in its surrounding basin, the presence of salmonids, and by its mixed regime, originated from snow melting in summer and rains in winter. The aim of the present study was to make a review of the inventory and ecological role of the benthic inland water macroinvertebrates of the River Cautin, in order to understand their importance in the ecosystem of the river. The fauna of this river includes a fauna composed of endemic and introduced fish, which has, however, been only poorly studied until now. The literature revealed the presence of abundant populations of Diptera, Trichoptera and Ephemeroptera larval stages, and few crustaceans specifically amphipods and freshwater crabs along the river’s course. Many of these macroinvertebrates are prey for both introduced salmonids and native fishes. Similar results have been reported for other southern Argentinean and Chilean Patagonian rivers.

Viral antigens are key in the development of vaccines that prevent or eradicate infections caused by these pathogens. Bioinformatics tools are modern alternatives that facilitate the discovery of viral antigens, reducing the costs of experimental assays. We developed a bioinformatics tool called VirVACPRED, which is highly efficient in predicting viral antigens. In this study, we obtained a model based on the gradient boosting classifier, which showed high performance during the training, leave-one-out cross-validation (accuracy = 0.7402, sensitivity = 0.7319, precision = 0.7503, F1 = 0.7251, kappa = 0.4774, Matthews correlation coefficient = 0.4981) and testing (accuracy = 0.8889, sensitivity = 1.0, precision = 0.8276, F1 = 0.9057, kappa = 0.7734, Matthews correlation coefficient = 0.7941). VirVACPRED is a robust tool that can be of great help in the search and proposal of new viral antigens, which can be considered in the development of future vaccines against infections caused by viruses.

No abstract

Daphnia pulex is a freshwater planktonic crustacean, allegedly a cosmopolitan species, which is found in lentic ecosystems. The aim of this study was to conduct a literature review of D. pulex related to its life history and genetic variability, in order to mark a route for future studies. We noted that D. pulex is a model species on which ecological studies have been carried out, as well as molecular studies, in which its molecular diversity has been characterized and such in specimens from different environments: both pristine and under human influence. In particular those studies are highlighted, in which molecular tools have been used to construct phylogenetic trees for study intraspecific differences. Also, in some of these molecular studies, analyses of genetic, inter- and intraspecific diversity have been performed. In addition, analyses of protein expression in D. pulex and related species seem promising in evaluating the detailed role of this species.

Lately, agriculture, livestock, forestry, and aquaculture activities have been greatly developed in Chilean North Patagonia, negatively impacting the balance of the environmental conditions in lakes and affecting the development and survival of several native species. The aim of this study was to assess the anthropic impact on a zooplankton community in two North Patagonian lakes. We collected samples from four sites belonging to Lake Icalma and Lake Llanquihue, including four replicates per site. Water samples were analyzed for physicochemical characteristics and zooplankton communities. We focused on the presence of Daphnia pulex, a species of zooplanktonic crustacean that performs a key role in capturing energy from primary producers to deliver it to final consumers such as fish. We found that Llanquihue showed higher total phosphorus, nitrogen, copper, iron, manganese, total dissolved solids (TDS), and conductivity (EC) than Icalma. Furthermore, ecological variables were greatly decreased due to total P, total N, manganese, copper, total dissolved solids, and conductivity, which changed the species dominance of the zooplankton community in Llanquihue, indicating some degree of anthropization. This study provides fundamental information on the anthropogenic impact on water quality, as well as on zooplankton diversity, highlighting the importance of monitoring the health of these North Patagonia freshwater ecosystems.

No abstract

Aquatic insect communities in inland waters of Chile are characterised by the presence of certain species depending on water quality, but there is little information on statistical ecology in the structure of insect communities. The aim of the present study was to apply null models to explain the structure of aquatic insects in the middle zone of the Loa River, in the Atacama Desert (Antofagasta Region, Chile; 23°S). The results of the null models of species co-occurrence showed that species associations are random, while niche sharing showed that species share ecological niches and consequently there is interspecific competition. The reported taxa are similar to communities for other North Patagonian rivers in terms of community structure.

No abstract