Data on taxa composition of freshwater zooplankton and meiobenthos across Arctic regions of Russia

We present the presence/absence species list (Table 1) of rotifer, cladoceran, and copepod (Calanoida, Harpacticoida, and Cyclopoida) fauna from seven Arctic regions of Russia (the Kola Peninsula, the Pechora River Delta, the Bolshezemelskaya tundra, the Polar Ural, the Putorana Plateau, the Lena River Delta, and the Indigirka River Basin) based on our own and literature data. Our own records were obtained by analyzing samples of zooplankton, meiobenthos, and two cores of bottom sediments (from the Kola Peninsula and the Bolshezemelskaya tundra lakes) that we collected once in July or August in 1992, 1995–2017. To supplement the list, we used relevant literature with periods of research from the 1960s to the 2010s. The list is almost identical to “Dataset 2: Zooplankton and Meiofauna across Arctic Regions of Russia”, which was analyzed but not published in [1]. The detailed analysis of this list revealed the specific composition of the aquatic fauna associated with the climatic and geographical factors [1]. The data provide information on the current state of biodiversity and species richness in Arctic fresh waters and can serve as the basis for monitoring these environments and predicting how they are likely to change in the future.


a b s t r a c t
We present the presence/absence species list (Table 1) of rotifer, cladoceran, and copepod (Calanoida, Harpacticoida, and Cyclopoida) fauna from seven Arctic regions of Russia (the Kola Peninsula, the Pechora River Delta, the Bolshezemelskaya tundra, the Polar Ural, the Putorana Plateau, the Lena River Delta, and the Indigirka River Basin) based on our own and literature data. Our own records were obtained by analyzing samples of zooplankton, meiobenthos, and two cores of bottom sediments (from the Kola Peninsula and the Bolshezemelskaya tundra lakes) that we collected once in July or August in 1992, 1995-2017. To supplement the list, we used relevant literature with periods of research from the 1960s to the 2010s. The list is almost identical to "Dataset 2: Zooplankton and Meiofauna across Arctic Regions of Russia", which was analyzed but not published in [1] . The detailed analysis of this list revealed the specific composition of the aquatic fauna associated with the climatic and geographical factors [1] . The data provide information on the current state of biodiversity and species richness in Arctic fresh waters and can serve as the basis for monitoring these environments and predicting how they are likely to change in the future.
© 2021 The Author(s

Value of the Data
• The data provide information on the current state of biodiversity and species richness in fresh waters of seven Arctic regions of Russia and can serve as the basis for monitoring these environments. They are related to the research article: [1] (Fefilova et al.), and are important for better understanding of the analyses performed in [1] . • The data are valuable for scientists who study biogeography of freshwater micro-invertebrates.
They may be used in applied sciences for estimation of regional resources for natureconservation measures . • These data are valuable for future analysis, i.e. for detailed and in-depth analysis of the distribution of certain species or groups (Rotifera, Cladocera, Copepoda), analysis of their range, etc. • It is believed that the fauna of aquatic invertebrates in the Russian part of the Arctic has been poorly studied. This opinion is also supported by the limited access to raw data (mostly unpublished). Thus, these data enrich the fundamental knowledge about the composition of zooplankton and meiobenthos in the high latitudes of Russia.

Data Description
The presence/absence list of micro-invertebrate taxa from planktonic and benthic samples collected in inland continental waterbodies of seven regions in the Russian Arctic is provided in Supplementry Table 1 . The Table contains a compiled list of the lower-rank taxa of microinvertebrates (Rotifera, Cladocera and Copepoda) for the regions, which summarizes taxa from our own studies and additional species from literature marked by the number of Reference. This is freshwater fauna of chiefly lentic inland waters, based on modern taxonomy of the groups under study. Each column of Table 1 corresponds to one region: the Kola Peninsula (Region I), the Pechora River Delta (Region II), the Bolshezemelskaya tundra (Region III), the Polar Ural (Region IV), the Putorana Plateau (Region V), the Lena River Delta (Region VI), and the Indigirka River Basin (Region VII). The detailed analysis of the list of taxa is given in [1] , where it is called "Dataset 2: Zooplankton and Meiofauna across Arctic Regions of Russia". Here we publish this Dataset for the first time ( Table 1). The number of species (species richness) in this Table 1 is equal to the number of species in Table 1 in [1] from Dataset 2 except the number of Cyclopoida species in Region II (15 versus 14, respectively), for which one species, Thermocyclops oithonoides , was omitted in Dataset 2. Note that this list is not suitable for analyzing temporal trends in species composition, they have been analyzed in [1] in separate regions, for example, III and VI.

Data sources and study design
Our study area encompasses seven inland Arctic regions of Russia: the Kola Peninsula (Region I), the Pechora River Delta (Region II), the Bolshezemelskaya tundra (Region III), the Polar Ural The list of species of zooplankton and meiofauna contains our own findings and literature data chiefly for the period from the 1960s to the 2010s (1960-2017). Our own findings were obtained by analyzing samples of zooplankton, meiobenthos, and two cores of bottom sediments (from Regions I, Lake Antyuh-Lambina, and III, Lake Kharbey) that we collected once in summer (in July or August).
Specifically, the data for Region I included our sediment core information from one lake (Antyuh-Lambina) obtained in 2015 and lists of the species of zooplankton and benthic microcrustaceans in waterbodies on the Kola Peninsula [2][3][4] . Data set for Region II included our own list of planktonic and benthic micro-fauna species of the Pechora River Delta based on 60 plankton samples collected in 2016 and 2017. For Region III, we used our data on more than 55 lentic waterbodies (lakes, ponds and pools), previously partly published in [9,10] , our unpublished data on lentic and lotic waters, and lists of planktonic and benthic micro-fauna of the Bolshezemelskaya tundra provided by other authors [5][6][7] , for the entire period of 1960-2013; the total number of samples was more than 360 planktonic and more than 400 benthic ones. Our sediment core information from one lake of Region III (Lake Kharbey) obtained in 2012 was also included in the species list. Region IV comprised only our own list of zooplankton and meiofauna species from 9 lakes located on the western slope of the Ural Mountains. They were studied in 2003 (2 lakes), 2010 (1 lake), and 2013 (6 lakes); 21 plankton and 23 benthos samples were taken. For Region V, we provided our list of zooplankton species from 38 waterbodies (lakes, including deep and large lakes -Lama, Glubokoe, and Kutaramakan, and ponds), from which some parts were previously published [10][11][12] , with additional species from the list of plankton fauna for lakes and reservoirs of the Putorana Plateau compiled by [8] . All 38 waterbodies were sampled during 20 01-20 04, and 4 of 38 again in 2011; the total number of samples was 94. Data [8] embraced the period from the 1960s to the 20 0 0s. In Region VI, we used our plankton fauna list from 20 waterbodies (lakes and ponds) sampled in 1995, 1996 (4 waterbodies), during 20 0 0-2017 (14 waterbodies) and 2014-2016 (2 lakes), which had been partly published previously, in [13] . In total, 558 plankton samples from this region were analyzed. For Region VII, we only used our own data on zooplankton composition in one lake (Suturuoha) and 27 polygonal ponds in the lower reaches of the Indigirka River. From the Suturuoha Lake, 16 plankton samples were collected in 2015; from ponds of this region 27 plankton samples (1 per waterbody) were taken in 2011. Thus, minimal sampling effort was rather high, namely, 44 samples in Region IV and 43 samples in Region VII; in Region III and Region VI sampling effort was maximal.

Field and laboratory methods
Zooplankton samples (for all published and unpublished data sets) were collected using plankton nets or Ruttner samplers with subsequent filtration through 82-100 μm mesh nylon nets. Similarly, all benthic micro-crustaceans in fine sediments were sampled using the Petersen dredge (sampling area 0.025 m 2 ), while those on rocky bottoms and from shallow depths were collected by a handle blade trawl or net with mesh size ≤230 μm. Samples were preserved in 90-96% ethanol or 4% formaldehyde (in the field) and examined under light microscopes in the laboratory.
For the paleoecological study of cladocerans from a Bolshezemelskaya tundra lake (Lake Kharbey), a short (25 cm) sediment core was collected using a UWITEC piston corer. From a Kola Peninsula lake, a sediment core was collected with a rod-operated half-tube corer (Russian peat corer: a 5 cm diameter, 100 cm long sampler). For subfossil Cladocera analysis, the cores were divided into 1-2 cm subsamples, each subsample was dissolved in 10% KOH and heated to 75 °C for 30 min. The resulting suspension was sequentially sieved through 63 μm sieves for Lake Kharbey and 50 μm for Lake Antyukh-Lambina. All subsamples were examined under a light microscope in laboratory.

Taxonomic analysis
All species within Rotifera, Cladocera, and Copepoda were identified in zooplankton samples, while only Cladocera and Copepoda were identified in benthic samples. For identification of species and higher-level taxa, we used both standard keys and data reported in modern studies specifically addressing the taxonomy of these groups. Species that actually represented groups of related species were identified as species (s. lat.) according to descriptions in taxonomic keys and studies [14][15][16][17] .

Ethics Statement
The work did not involve the use of human subjects, animal experiments and data collected from social media platforms.

Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships which have or could be perceived to have influenced the work reported in this article.
The work was performed in part as Federal Tasks to the Department of Animal Ecology of the Institute of Biology of Komi Science Centre of the Ural Branch of the Russian Academy of Sciences ( АААА-А17-117112850235-2 ) (to EF and OK), to the Institute of Biophysics of the Federal Research Center "Krasnoyarsk Science Center" of the Siberian Branch of the Russian Academy of Sciences (project No. 51.1.1) and the Siberian Federal University (project No. FSRZ-2020-0 0 06 ) (to OD). The paleolimnological part of this work was supported by grant from Russian Science Foundation (project 20-17-00135 ). L. Frolova and G. Nigamatzyanova were supported by the subsidy allocated to Kazan Federal University for the state assignment # 671-2020-0049 in the sphere of scientific activities and by the Russian Foundation for Basic Research (grant 18-05-00406 ). The work was partly financially supported by the Russian Foundation for Basic Research (RFBR) grant: 20-04-00145_ а (to EF). Monitoring investigations in the Lena River Delta were conducted under the framework of Russian-German, "Lena" expeditions (Alfred Wegener Institute, Potsdam, Germany) with logistic and technical support of Scientific Research Station "Samoylov Island" (the Trofimuk Institute of Petroleum-Gas, Geology and Geophysics SB RAS, Novosibirsk) (to EA).

Supplementary Materials
Supplementary material associated with this article can be found in the online version at doi: 10.1016/j.dib.2021.107112 .