Ecological role of benthic crustaceans in Chilean north Patagonian lakes and rivers (Araucania region, 39°S)

Abstract

The Chilean north Patagonian inland waters are characterized by their low mineral concentrations. In their original status, many of these ecosystems have native vegetation in their surrounding drainage basins, but in the last decades the native vegetation was replaced by agricultural, urban, and industrial zones, with as a result of these human alterations that those aquatic communities changed. The aim of the present study was to make a literature review about the ecological role of crustaceans in Chilean north Patagonian lakes and rivers. The literature mentioned the presence of amphipods (Hyalella), crayfishes (Samastacus spinifrons), and freshwater crabs (genus Aegla), and many of these species hold a conservation risk due to the consequences of habitat damage and/or their high endemism. These crustaceans are important for the degradation of particulate organic matter originating from the surrounding vegetation, and are prey for native and introduced salmonid fishes. Similar patterns had already been observed for Argentinean Patagonian rivers.

First report of inventory and role of macroinvertebrates and fish in Cautín river (38° S, Araucania region Chile)

“…The literature seems to indicate that benthic invertebrates would have a marked gradient in heterogeneity as a function of the gradient in water conditions of the Cautin river ( Figure 1), as in this aspect it is similar to existing descriptions of other Patagonian rivers (Arenas, 1995;Figueroa et al, 2003Figueroa et al, , 2007Figueroa et al, , 2010Figueroa et al, , 2013Fierro et al, 2012Fierro et al, , 2015Fierro et al, , 2016Encina et al, 2017). Previous reports thus indicate that the taxa Plecoptera, Ephemeroptera and Trichoptera larval stages and Aegla are abundant under turbulent flow, associated with a high oxygen concentration and much particulate matter that makes a food source (Oyanedel et al, 2008;Moya et al, 2009).…”

“…The literature about macroinvertebrates in this kind of rivers is quite fragmented, and mainly describes the presence of Malacostraca such as amphipods of the genus Hyalella (S.I. Smith), freshwater crabs of the genus Aegla (Leach, 1820), and the southern Chilean river prawn, Samastacus spinifrons (Phillippi, 1882) (De los Ríos-Escalante et al, 2012;Jara, 2013;Rudolph, 2013), and Diptera, Trichoptera and Ephemeroptera larval stages (Figueroa, 2000;Figueroa et al, 2003Figueroa et al, , 2007, many of these groups are currently endangered due to human-induced alterations in their habitats and the introduction of alien salmonids species since 1914 (Golusda, 1907(Golusda, , 1927Barros, 1931;Jara et al, 2006;Encina et al, 2017;Vega et al, 2017). The (introduced) salmonids, specifically, constitute non-selective, active predators (Soto et al, 2006(Soto et al, , 2007Fierro et al, 2012Fierro et al, , 2015Fierro et al, , 2016Piedra et al, 2012;Valdovinos et al, 2012;Vargas et al, 2010Vargas et al, , 2015.…”

Standard culture of Paratanytarsus grimmii Schneider, 1885 (Diptera: Chironomidae), for its use in toxicity bioassays.

“…In this scenario, if it is considered that many central Chilean rivers are exposed to pollution to different kinds of human activities (Figueroa et al, 2003(Figueroa et al, , 2007(Figueroa et al, , 2010(Figueroa et al, , 2013. If these ecosystems have many endemic species (Encina et al, 2017c;Vega et al, 2017), it would be necessary first do a specific characterization at species level of species of each site, as previous step for culture (Encina et al, 2017a, b) and bioassays studied compared with standardized species, and finally stablish local ecotoxicological protocols involving native species (Encina et al, 2017a, b).…”

Crustáceos acuáticos en arroyo Maquehue.

“…El presente estudio consistió en colecta de crustáceos bentónicos usando lances con una malla surber de 50 * 50 cm, en los meses de abril y mayo de 2016, el material se identificó en base a las descripciones de Domínguez & Fernández (2009) Los presentes resultados concuerdan con reportes para la literatura para ríos de la región (Correa-Araneda et al, 2010a,b;Encina et al, 2017;Vega et al, 2017), donde es posible encontrar ambas especies en ambientes poco contaminados, si bien la literatura menciona la presencia de Aegla de preferencia en zonas de río con baja intervención antrópica. Por otro lado, la presencia de S. spinifrons en bajas abundancias concordaría con reportes de la literatura que indican que esta especie presenta amenazas en cuanto a sus abundancias por explotación, así como contaminación de los hábitats (Jara et al, 2006).…”