Checklist of free-living microturbellarian flatworms (Turbellaria, Platyhelminthes) in the Suquía River Basin, Córdoba, Argentina

Free-living microturbellarians are a part of lentic and lotic aquatic assemblages and play an important but underestimated role in aquatic ecosystems. Consequently, they are not included in studies on the dynamics of freshwater aquatic invertebrate communities. We report eight new records of microturbellarians from the Suquía River (Córdoba, Argentina): Catenula lemnae Dugès, 1832, Stenostomum arevaloi Gieysztor, 1931, Stenostomum aff. amphotum Marcus, 1945, Macrostomum aff. quiritium Beklemischev, 1951, Macrostomum platensis Adami, Damborenea & Ronderos, 2012, Microstomum sp., and Mesostoma erhenbergii (Focke, 1836). We discuss these results within the geomorphological history of the river basin

The fauna of aquatic invertebrates in the river impacted by wastewaters from the pulp and paper industry (Komi Republic)

Invertebrates are important elements of aquatic ecosystems and play a crucial role in the transformation of matter and energy in continental water bodies. Communities of aquatic invertebrates are characterised by high sensitivity to pollution by nutrients and toxic substances and acidification of water bodies; they serve as good bioindicators of the quality of the aquatic environment and impacts on hydroecosystems. All hydrobionts participate in the processes of self-purification of water bodies. The presented dataset provides information on the aquatic invertebrate community of a large northern river. During 2018-2020, we collected data on changes in the quantitative indicators of the development of benthic and planktonic communities, as well as the species diversity of their fauna. The dataset combines information about the occurrence and abundance of benthic and planktonic invertebrates and summarises data of aquatic invertebrate species found in the Vychegda River in the zone of influence from the pulp and paper mill. The presented dataset is part of a monitoring programme of the river ecosystems in the production area of Mondi Syktyvkar JSC (the European North-East of Russia, Komi Republic). The dataset describes the structure of benthic invertebrate and plankton communities in the Northern Dvina River Basin. The data on the finding and abundance of large taxa of aquatic invertebrates and species of some groups: Oligochaeta, Cladocera, Copepoda, Rotifera, Ephemeroptera, Plecoptera and Trichoptera are presented. In total, the resource includes 8720 findings of invertebrates, of which 6041 are for zoobenthos organisms and 2679 for zooplankton organisms.

Recovery of freshwater invertebrates in alpine lakes and streams following eradication of nonnative trout with rotenone

Nonnative fish eradication via the piscicide rotenone is an effective tool for fisheries management and conservation of native species. However, the long-term effects on non-target organisms, including benthic invertebrates and zooplankton in alpine lakes, are under-studied and are poorly understood. As part of a landscape-scale native fish conservation project, we assessed the effects of 50 ppb rotenone on the aquatic invertebrate community by comparing pre- and post-rotenone treatment density and diversity metrics of benthic invertebrates and zooplankton in 13 alpine lakes and their outlets in Montana, USA. Across study sites, decreases in density and diversity of some invertebrates, including Ephemeroptera, Plecoptera, and Trichoptera taxa, were observed the year following rotenone treatment, and within three years, densities and diversities were similar to and sometimes higher than pre-treatment values. These results demonstrate resilience of aquatic invertebrate communities following rotenone exposure in alpine lakes and streams and informs fisheries managers for planning rotenone projects and monitoring recovery of non-target organisms. Further studies will be useful to evaluate the mechanisms driving invertebrate recovery rates, including downstream drift from nontreated areas and terrestrial adult dispersal.

Invertebrate hydrobiont fauna transformation in the Dombrovskyi pit lake during the period of 2014-2018

The aquatic invertebrate community of Dombrovskyi pit lake was investigated during 2014–2018. 25 species were recorded there. The only permanent component of plankton in the community is rotifer Brachionus plicatilis Müller, 1786; of benthos and neuston is hemipteran Sigara lateralis (Leach, 1817), beetle Hydrobius fuscipes (Linnaeus, 1758), flies Aedes sp., Ochlerotatus lepidonotus (Edwards, 1920), Culicoides salinarius Kieffer, 1914, Ephydra glauca Meigen, 1830 are permanent components of benthos and neuston. The main diversity of invertebrates is concentrated in littoral zone up to 2 m of depth. This is primarily due to the desalination of these areas by surface runoff. Over the last decade the mineralization of the surface water layer has decreased from 120–138 to 25–28 g/l. Combined with the desalination of water, the increase of species diversity of aquatic invertebrates was noticed in spring seasons (from 7 to 17 taxa). The freshwater taxa, which are not tolerant even to low water salinity, appeared in the community in 2018 (7–25 % of the species diversity), among them Hydrometra stagnorum (Linnaeus, 1758), Rhyacophila tristis Pictet, 1834, Coelambus impressopunctatus (Schaller, 1783), Enochrus coarctatus (Gredler, 1863), Hydrophilus caraboides (Linnaeus, 1758). The role of freshwater taxa, which are tolerant to low water salinity (up to 5 g/l), increased from 0–10 % of the species diversity in 2014–2015 to 22–35 % in 2018. Among them Eucyclops serrulatus (Fischer, 1851), Candona sp., Cypris pubera O. F. Müller, 1776, Cloeon dipterum (Linnaeus, 1760), Libellula depressa Linnaeus, 1758, Sympecta fusca Vander Linden, 1820, Paracorixa concinna (Fieber, 1848) was noted in 2018 for the first time. On the contrary, the number of saltwater taxa decreased from 20–29 % (2014–2015) to 5–14 % (2018). The saltwater aquatic invertebrate community of this pit lake has transformed into brakish-freshwater one over time. 83 % taxa of aquatic invertebrate communities from freshwater puddles near reservoir coast are noted in the Dombrovska reservoir. The introduction of species from protective canals of the reservoir is unlikely, as only 5 % of taxa from there are marked in it. The main way of the forming communities of invertebrates in this reservoir is the periodical flooding of freshwater coastal puddles.