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Taxonomic composition of zoopsammon in fresh and brackish waters of Estonia, a Baltic province ecoregion of Europe.

INTRODUCTION

Zoopsammon is a diverse group of organisms living in the interstitial spaces between sand grains at the shoreline. The term psammon is nowadays mainly used to characterize freshwater sandy beach habitats, although it was originally defined as 'a transitional zone between aquatic and soil habitats' (Schmid-Araya, 1998), and is also applicable to brackish and marine beach habitats, where the intertidal zone can be considered as psammon habitat if the sediment consists of sand and is regularly exposed (e.g. Tzschaschel, 1983; Golemansky, 1998; De Smet and Chernyshev, 2006; Alekperov et al., 2007). However, in the marine literature psammic comunities are more often referred to as meiofauna.

Psammon communities have received very little attention compared to lower littoral and sublittoral meiobenthos, and psammon has been rarely treated as a single entity. Despite its unstable and very fluctuating environment, the arenal zone hosts a large variety of species (Pejler, 1995; Golemansky, 1998; Gheskiere et al., 2005). Protists, nematodes, rotifers, small crustaceans, tardigrades, gastrotrichs, turbellarians, oligochaetes, and insect larvae are regularly found from psammon habitats (Thane-Fenchel, 1968; Whitman and Clark, 1984; Schmid-Araya, 1998, Kotwicki et al., 2005a, 2005b). From psammic taxa, rotifers have received relatively much attention in freshwater habitats (e.g. Pejler, 1995; Bielariska-Grajner, 2001; Segers and Chittapun, 2001). In marine beach habitats, nematodes tend to be the most thoroughly researched psammic taxa (e.g. Gheskiere et al., 2004, 2005; Liu et al., 2008; Maria et al., 2012, 2013).

From the Baltic Sea area some information is available on psammic ciliates (Czapik and Fyda, 1992), testate amoebae (Golemansky, 1998), rotifers (Thane-Fenchel, 1968; Sorensen, 2001), and nematodes (Gheskiere et al., 2005). In Europe, freshwater zoopsammon has received more attention in Poland (e.g. Bielariska-Grajner, 2001; Ejsmont-Karabin, 2003; Nesteruk, 2007; Kalinowska, 2008, 2013; Bielaiska-Grajner and Poznaiska, 2010).

At the Estonian water bodies, the coastal zone was sampled already in the 19th century. In these studies, some beach invertebrates were recorded (Eichwald, 1849, 1852; Levander, 1894). However, it is not known where exactly the samples were taken (water or sediment, at waterline/beach or deeper water). First true reports on the interstitial fauna, i.e. zoopsammon, of sandy beach in Estonia date from the 1980s. In these sampling campaigns, Golemansky (1983) investigated psammic testate amoebae from the Estonian coast of the Gulf of Finland, and Kutikova and Haberman (1986) determined the taxonomic composition of rotifers from the arenal zone of Lake Vortsjarv. Recently, some information has been provided about the taxonomic composition and density of zoopsammon communities, their temporal and spatial distribution, and relation with various environmental variables in some Estonian coastal beaches (Lokko et al., 2014) and in two lakes (Lokko et al., 2013; Lokko and Virro, 2014).

The aim of this study is to provide an overview and sum up the current knowledge on the taxonomic structure of zoopsammon in Estonian waters. This summarized information serves as a basis of the current status of psammic communities both in freshwater and marine habitats and potentially allows assessing the current status and conservation value of Estonian interstitial beach habitats.

MATERIALS AND METHODS

The present study is based on two previous studies (Lokko et al., 2013, 2014) and an additional sampling campaign carried out in 2011-2014. Samples were taken from three sandy beaches along the Estonian coast of the Gulf of Finland, Baltic Sea, and from four lakes across Estonia (Fig. 1). The coastal sampling sites were located at Keibu Bay near Nova village (Nova Beach, the westernmost sampling site), at Pirita Beach within Tallinn City, and at a popular beach of Narva Bay adjacent to a small town of Narva-Joesuu (the easternmost site). The Gulf of Finland has a strong horizontal salinity gradient: the surface salinity varies from 0 in its eastern end to 7 ppt in the western areas (Pitkanen et al., 2008). Also nutrients input and trophic state increase from west to east, and the gulf is considered one of the most eutrophicated basins in the Baltic Sea area (HELCOM, 2003; Pitkanen et al., 2007).

The sampling sites from lakes were located at the eastern coast of Lake Vortsjarv, at two beaches of Lake Saadjarv, at Lake Verevi, and at Lake Manniku. Vortsjarv is the second largest lake in Estonia (surface area 27 000 ha). It is a shallow (max depth 6 m, average 2.8 m) eutrophic lake with a short water residence time (Timm, 1973; Tuvikene et al., 2004). Saadjarv is smaller (surface area 707.6-723.2 ha), but much deeper (max depth 25 m, average 8 m) (Maemets, 1977; http://register.keskkonnainfo.ee/envreg/main?reg_kood= VEE2065300&mount=view, accessed 29.06.2014). Saadjarv has the lowest trophic status of the studied lakes. The mesotrophic Saadjarv is characterized by slow water exchange rates, high water transparency, high hardness, and alkaline water (Ott, 2007). The smallest of the studied lakes is Verevi, which is located in a small town of Elva and is very popular among swimmers. It is a hypertrophic and relatively deep (max 11 m, average 3.6 m, surface area 12.6 ha) lake with a low water exchange rate (Loopmann, 1984; Ott et al., 2005). The fourth of the studied lakes, Manniku, is located at the edge of Tallinn City. It is a moderately deep (max depth 9 m, average 5 m, surface area 118.7 ha) eutrophic lake of anthropogenic origin (Tamre, 2006; http://register.keskkonnainfo.ee/envreg/main#HTTPb8aODzH81I2Zv8PJCBXuHAhsXWViIR, accessed 29.06.2014) with steep slopes. It belongs to a complex of several lakes/water bodies within a sand quarry, which was established in the early 20th century. The main characteristics of the studied beaches, coordinates, and sampling times are presented in Table 1.

In each sampling site, samples of psammon were collected along transects across the waterline (up to 50 cm from the waterline in both directions). The samples were collected with sharp-edged corers with diameters of 2.9 and 4.75 cm down to a depth of 3-5 cm in the sand. The samples were transferred to a plastic container and rinsed three times with carbonated drinking water. After each rinse the supernatant was poured off into a plastic bottle and fixed with Lugol's solution. Then the samples were condensed to 100 mL by sedimentation for at least four days and siphoning off excess water. From each sample, five 2-mL subsamples were taken wherein all organisms were counted in a Bogorov chamber under a microscope. For the identification, specimens were slide-mounted in glycerol and determined to the lowest possible taxon. Illoricate rotifers were identified by their trophi, which were dissolved out using the household disinfectant Domestos[R], which contains sodium hypochlorite (NaClO < 5%). At each sampling time various environmental parameters such as sand grain size, vegetation coverage, sand organic content, pH, temperature, and salinity were estimated. The details of measuring and estimating environmental parameters are described in Lokko et al. (2013, 2014).

The nomenclature of higher taxonomic units is based on the classifications in Halanych (2004), the Catalogue of Life (Roskov et al., 2014), and the World Register of Marine Species (WoRMS Editorial Board, 2014), and those of rotifers on Melone et al. (1998) and Sorensen and Giribet (2006). The classification of protists is based on Mazei and Tsyganov (2006) and Cavalier-Smith (2010). The nomenclature of rotifer species follows Jersabek et al. (2012). For testaceans, Mazei and Tsyganov (2006) was used. In other cases, the Catalogue of Life (Roskov et al., 2014) was consulted.

The Sorensen index (Krebs, 1989) was used to evaluate similarity between zoopsammic communities of the sampling sites. In order to identify clusters of stations that are statistically dissimilar, a similarity profile (SIMPROF) test was used (Clarke et al., 2008) in the R environment and package clustsig (R Core Team, 2014; Whitaker and Christman, 2014).

RESULTS AND DISCUSSION

A total of 156 non-overlapping taxa belonging to 12 phyla were found in the Estonian psammon communities, 69 taxa occurring in the Gulf of Finland and 123 taxa in lakes (Table 2). In our preceding studies (Lokko et al., 2013, 2014), 46 new zoopsammon taxa for the Estonian fauna were registered, including 25 rotifers, 17 testate amoebae, 1 cercozoan, 1 clitellate, 1 tardigrade, and 1 harpacticoid. The present study further adds new records of 11 rotifer, 19 amoebozoan, and 6 nematode taxa for Estonia (Table 2). Of all the taxa found, 90 occurred only in lake beaches and 39 in beaches of the Baltic Sea. The number of taxa per sample was higher in lake beaches than in coastal areas. Areal taxonomic richness was related to sample taxonomic richness in coastal areas but not in the lake ecosystems (Fig. 2). The most common taxa were nematodes, rotifers, ciliates, testate amoebae, and harpacticoids. Individuals from these taxa were found from all studied beaches. No oligochaetes were found from the beach of Lake Verevi. The most taxon-rich season was summer, whereas diversity peaked later in lake (in August) than in coastal beaches (June or July).

Rotifers are one of the main groups of zoopsammon. As compared to other psammic taxa, rotifers have received much more attention (e.g. Bielanska-Grajner, 2001, 2005; Ejsmont-Karabin, 2001, 2003, 2005; Thane-Fenchel, 1968), at least in freshwater habitats. This gives a possibility of comparing communities among different water bodies and making assumptions about the ecological status and overall taxonomic richness of a water body. Rotifers are ideal for analysing relationships between habitat and community as this group of invertebrates are very diverse, giving often the highest number of species to local diversity, and cosmopolitan to a large extent (Pejler, 1995; Segers, 2008). In our material, the majority of rotifer species belong to the families Dicranophoridae (18% of the 84 identified species), Notommatidae (18%), and Lecanidae (18%). The most diverse genus was Lecane (15 species), followed by Cephalodella (10) and Encentrum (7). Domination of these families and genera is typical of psammic communities (Schmid-Araya, 1998). According to the present information on global distribution of rotifers (Segers, 2007; Jersabek and Leitner, 2013), of the rotifer species recorded in the psammon of the studied water bodies, 48 (58%) are cosmopolitan and other 22 (27%) have a wide distribution covering both Palaearctic and Nearctic, several of these are also known from some other biogeographic regions. Eleven (13%) species are restricted to Palaearctic. The occurrence of Encentrum belluinum in the samples from the Estonian coast of the Gulf of Finland and Notommata stitista in Lake Vortsjarv is of interest. These two species are presently reported only from the Nearctic region. Probably N. stitista is a rare species, as it has not been found since its discovery (Nogrady et al., 1995). Our findings indicate a potential Holarctic distribution of these two species. Cephalodella intuta, C. tenuiseta, Lecane doryssa, Notommata doneta, and Pleurata vernalis are also regarded as rather rare (Nogrady et al., 1995; Segers, 1995). The presence of L. doryssa and L. punctata is noteworthy for their known cosmotropical-cosmosubtropical distribution (Segers, 1995). The range of these warm-stenotherms appears to be wide, reaching the temperate zone where they can find suitable conditions during summer months. A peculiar female specimen of Monommata sp. was encountered in a sample from Lake Verevi. The rotifer has toes of equal length like Monommata aequalis (Ehrenberg, 1830), but differs from it having a smaller body and uniformly wide blade-like toes, which to our knowledge are dissimilar from the previously described Monommata taxa. However, further study based on sufficient material is needed for a formal description of a possible new taxon.

Testate amoebae are another key component of psammon, although much less information is available about this highly diverse group. Unfortunately, we currently lack the taxonomic competence of free-living nematodes in Estonia. Therefore nematodes have received very little attention in freshwater psammon and it is not possible to make any interregional comparisons.

In the studied lakes the number of taxa decreased with increasing trophic state. The zoopsammon of the mesotrophic Lake Saadjarv had the highest taxonomic diversity among the studied beaches with a total of 81 taxa from 10 phyla. Altogether, 65 taxa were found from the eutrophic Lake Vortsjarv. The zoopsammon of the hypertrophic Lake Verevi consisted only of 42 taxa. However, this pattern applied only to the overall number of taxa and the number of rotifer taxa. The number of testate amoebae species had a reversed pattern. Nevertheless, as the total number of samples varied from lake to lake, it may not reflect the true relationship between diversity and trophic state of the lake. Moreover, dominant ciliates, nematodes, and bdelloids were generally not identified to lower taxa, which may further bias the overall pattern of diversity. However, a similar relationship between the number of rotifer species and trophic state was found in a study carried out in Poland, where more rotifer species were found in lakes with a lower trophic status (Bielahska-Grajner, 2005). In another study in the same ecoregion the species richness was notably lower in hypertrophic lakes (Ejsmont-Karabin, 2003).

Taxonomic richness per sample was the highest in Lake Manniku, probably due to good environmental conditions for a large number of taxa at the time of sampling. Based on the sampling campaign carried out in 2011-2012, the highest average number of taxa per sample was recorded in Lake Vortsjarv and lowest in Lake Saadjarv (Fig. 2). In 2008 the average number of taxa per sample in Lake Saadjarv was somewhat higher, yet lower than in the hypertrophic Lake Verevi in 2011-2012. While Saadjarv has a lower trophic status than the other studied lakes it is possible that the habitat can support a lower number of taxa in a small patch at a given time and the overall high number of taxa in the lake was provided by the high patchiness and complex seasonal dynamics.

In coastal areas the sample taxonomic richness was lower than in lake beaches. It followed the same pattern as sea-scape taxonomic richness, indicating that compared to lakes beach habitats in coastal areas were more homogeneous in space and time.

Our study also suggested a similar pattern between the trophic state and the number of psammic taxa in coastal beaches with the number of taxa decreasing with increasing anthropogenic impact. The lowest taxonomic richness (32 taxa, including 15 rotifer and 4 testate amoebae taxa) was recorded from Pirita Beach, which is located within Tallinn City adjacent to a yacht harbour and is a very popular beach. However, differently from lakes the number of testate amoebae taxa was likewise lower in coastal beaches with a higher anthropogenic impact.

Only 25 taxa were found from Lake Manniku. As this lake was represented by only one sample, the true biodiversity can be probably much higher. Moreover, the lake was sampled in May, which was not a season of high psammic taxonomic richness in any of the other studied lakes. Yet this sample represented the highest zoopsammon abundance recorded in Estonia (279 ind [cm.sup.-3]) so far.

The overall zoopsammon abundance was generally much higher in lake beaches than in coastal beaches. The maximum psammic abundance reached 203 ind [cm.sup.-3] in Lake Vortsjarv and 92.3 ind [cm.sup.-3] in Lake Saadjarv (Lokko et al., 2013), whereas for coastal beaches the respective value was only 46.6 ind [cm.sup.-3].

A total of 13 taxa of testate amoebae were recorded from the psammon of the Gulf of Finland in this study. Previously, Golemansky (1983) sampled beach sand from the Estonian coast of the Gulf of Finland and found 23 species of testate amoebae. Interestingly, the only overlapping taxa were Cyphoderia ampulla, Psammonobiotus communis, and Cyclopyxis sp. This is possibly caused by different sampling and analysing techniques and a wider habitat range (up to 16 m landwards from the waterline) compared to our study. Freshwater beaches had more testate amoebae species than coastal beaches. The testate amoebae community of Lake Verevi with 23 testate amoebae taxa seemed to have an especially high taxonomic richness.

The psammic rotifer community of the Gulf of Finland was represented by 35 taxa. This is similar to the numbers recorded from interstitial habitats in Scandinavia where Thane-Fenchel (1968) found 28 interstitial rotifer species from Asko Harbor. In Nova Beach with similar salinities we recorded 26 rotifer taxa. The number of rotifer species found in the psammon from lakes Vortsjarv and Saadjarv resembles the numbers previously recorded from some Polish lakes with a similar trophic level; moreover, quite a few species overlapped in the two countries (Radwan and Bielahska-Grajner, 2001; Ejsmont-Karabin, 2005).

The coefficients of Sorensen similarity between the studied areas are presented in Table 3. Lake Manniku was not included in comparisons as it was represented by only one sample. According to the Sorensen similarity coefficient, the zoopsammon communities of coastal sampling sites were much more similar with one another than zoopsammon at different lakes, and rotifer communities differed much more from beach to beach than testate amoebae communities. SIMPROF analysis showed that all sampling sites had significantly different psammic communities. Nevertheless, the coastal sampling sites clustered together, showing that their communities were more similar to each other than those of lakes (Figs 3 and 4).

Although this study compiled different data sets with different spatial and temporal extent, we were able to discover some generic psammic patterns in the Estonian fresh- and brackish-water bodies. In general, the abundance and richness of psammic taxa were higher in lake than in coastal beaches. Besides, variability between samples of psammon communities was higher in lake than in coastal beaches. Psammon taxonomic richness was higher in beaches with a lower trophic state and/or anthropogenic impact. However, such relationship appeared only at a wide spatial scale pooling a large number of samples. The sample taxonomic richness followed regional taxonomic richness only in coastal areas. This also suggests that the communities of psammon vary more in space and time in lake beaches than in coastal beaches.

doi: 10.3176/eco.2014.4.04

Received 21 July 2014, revised 26 September 2014, accepted 26 September 2011

ACKNOWLEDGEMENTS

Funding for this research was provided by Institutional research funding IUT0220 of the Estonian Research Council. The study has been also supported by the projects 'The status of marine biodiversity and its potential futures in the Estonian coastal sea' No. 3.2.0801.11-0029 of the Environmental Protection and Technology Programme of the European Regional Fund. We also thank Dr Tarmo Timm at the Centre for Limnology, the Estonian University of Life Sciences, for identifying the annelid taxa. We are also grateful for Dr Ilmar Kotta for estimating the organic content of sand in samples.

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Tuvikene, L., Kisand, A., Tonno, I., and Noges, P. 2004. Chemistry of lake water and bottom sediments. In Lake Vortsjarv (Haberman, J., Pihu, E., and Raukas, A., eds), pp. 89-102. Estonian Encyclopaedia Publishers, Tallinn.

Tzschaschel, G. 1983. Seasonal abundance of psammon rotifers. Hydrobiologia, 104, 275-278.

Whitaker, D. and Christman, M. 2014. clustsig: Significant Cluster Analysis. R package version 1.1.

Whitman, R. L. and Clark, W. J. 1984. Ecological studies of the sand-dwelling community of an east Texas stream. Freshwater Invertebrate Biology, 3, 59-79.

WoRMS Editorial Board. 2014. World Register of Marine Species. http://www.marinespecies.org at VLIZ (accessed 29.06.2014).

Kulli Lokko (a,b) ([mail]), Taavi Virro (a), and Jonne Kotta (b)

(a) Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, 51014 Tartu, Estonia

(b) Estonian Marine Institute, University of Tartu, Maealuse 10a, 12618 Tallinn, Estonia

([mail]) Corresponding author, kulli.lokko@ut.ee

Table 1. Sampling site coordinates, sampling time, and general
environmental characteristics in the sampling sites. Variable mean
(continuous variables) or most common value (categorical variables);
minimum and maximum value or variable range is shown in brackets

                                Vortsjarv

Sampling site                   58[degrees] 13'45"N;
  coordinates                   26[degrees] 07'17"E

Sampling time                   Mar-Nov 2008;
                                  May-Oct 2011,
                                  Apr 2012
Sand type                       Fine (fine-coarse)

Vegetation cover                15% (0-50%)
pH (littoral/                   7.73 (6.77-9.5)
  interstitial)
Porewater                       0.579 (0.446-0.775)
  conductivity, mS
Porewater salinity,             NA
  ppt
Sand temperature, [degrees]C    19.9 (8.7-30.2)
Sand organic content            1.06 (0.22-7.39)

                                Saadjarv

Sampling site                   58[degrees] 31'59"N;
  coordinates                   26[degrees] 38'46"E and
                                58[degrees] 31'41"N;
                                26[degrees] 41'45"E
Sampling time                   Apr-Oct 2008;
                                  May-Oct 2011,
                                  Apr 2012
Sand type                       Medium (medium-
                                coarse)
Vegetation cover                11% (0-60%)
pH (littoral/                   7.84 (6.92-9.4)
  interstitial)
Porewater                       0.626 (0.399-0.942)
  conductivity, mS
Porewater salinity,             NA
  ppt
Sand temperature, [degrees]C    16.6(5.1-28.3)
Sand organic content            0.72 (0.33-3.18)

                                Verevi

Sampling site                   58[degrees] 13'44"N;
  coordinates                   26[degrees] 24'21"E

Sampling time                   May-Oct 2011, Apr
                                  2012

Sand type                       Medium (fine-
                                medium)
Vegetation cover                19% (2-^0%)
pH (littoral/                   7.48 (6.63-7.98)
  interstitial)
Porewater                       0.629 (0.513-0.711)
  conductivity, mS
Porewater salinity,             NA
  ppt
Sand temperature, [degrees]C    20.1 (7.7-32)
Sand organic content            0.85 (0.22-4.77)

                                Manniku

Sampling site                   59021'35"N,
  coordinates                   24[degrees] 42'59"E

Sampling time                   May 2014

Sand type                       Medium-coarse

Vegetation cover                0%
pH (littoral/                   7.99 littoral
  interstitial)
Porewater                       NA
  conductivity, mS
Porewater salinity,             NA
  ppt
Sand temperature, [degrees]C    15.8
Sand organic content            NA

                                Nova

Sampling site                   59[degrees] 13'45"N,
  coordinates                   23[degrees] 42'8"E

Sampling time                   May-Oct 2011,
                                  Apr 2012

Sand type                       Medium (medium-
                                coarse)
Vegetation cover                0% (0-12%)
pH (littoral/                   8.19(6.68-9.11)
  interstitial)                 interstitial
Porewater                       11.05 (9.09-12.43)
  conductivity, mS
Porewater salinity,             5.41 (4-6.2)
  ppt
Sand temperature, [degrees]C    15.67 (6.2-23.2)
Sand organic content            0.53 (0.07-4.09)

                                Pirita

Sampling site                   59[degrees] 28'11"N,
  coordinates                   24[degrees] 49'38"E

Sampling time                   May-Oct 2011,
                                  Apr 2012

Sand type                       Medium (fine-
                                coarse)
Vegetation cover                0%
pH (littoral/                   7.86 (7.67-8.34)
  interstitial)                 interstitial
Porewater                       11.19(7.19-
  conductivity, mS                12.80)
Porewater salinity,             5.46 (3-6.6)
  ppt
Sand temperature, [degrees]C    15.16(6-22.6)
Sand organic content            0.59 (0.06-2.87)

                                Narva-Joesuu

Sampling site                   59[degrees] 27'8"N,
  coordinates                   28[degrees] 18"E

Sampling time                   May-Oct 2011,
                                  Apr 2012

Sand type                       Fine (fine-
                                medium)
Vegetation cover                0% (0-100%)
pH (littoral/                   8.18 (7.57-8.7)
  interstitial)                 interstitial
Porewater                       5.46 (0.72-9.09)
  conductivity, mS
Porewater salinity,             2.4 (0-4)
  ppt
Sand temperature, [degrees]C    14.99 (5.2-23.6)
Sand organic content            0.48 (0.04-2.43)

NA--not analysed.

Table 2. Zoopsammon taxa from beaches of lakes Vortsjarv, Saadjarv
(two sites), Verevi, and Manniku, and coastal beaches Nova, Pirita,
and Narva-Joesuu. Summarized information from previous studies
(Lokko et al., 2013, 2014) and recent supplementary material.
Asterisked (*) taxa are new records for Estonia

Taxon                                         Vortsjarv   Saadjarv

Phylum Amoebozoa
Class Lobosea
Order Arcellinida
Arcella sp.
Arcella artocrea Leidy, 1876 *
Arcella catinus Penard, 1890 *
Arcella crenulata Deflandre, 1928 *               x
Arcella discoides Ehrenberg, 1843                 x          x
Arcella hemisphaerica Perty, 1852                            x
Centropyxis aerophila Deflandre, 1929             x          x
Centropyxis aculeata (Ehrenberg, 1838)            x          x
Centropyxis cassis (Wallich, 1864)                x          x
Centropyxis constricta (Ehrenberg, 1841)          x          x
Centropyxis discoides Penard, 1902
Centropyxis delicatula Penard, 1902 *             x          x
Centropyxis ecornis (Ehrenberg, 1841) *           x
Centropyxis hirsuta Deflandre, 1929 *
Centropyxis cf. laevigata Penard, 1890 *
Centropyxis orbicularis Deflandre, 1929 *
Centropyxis platystoma Penard, 1890               x          x
Cyclopyxis spp.
Cyclopyxis arcelloides (Penard, 1902)             x          x
Cyclopyxis eurystoma Deflandre, 1929 *
Cyclopyxis kahli (Deflandre, 1929) *              x
Difflugia amphora (Leidy, 1874) Penard,
  1902
Difflugia bidens Penard, 1902                                x
Difflugia brevicolla Cash et Hopkinson,                      x
  1909 *
Difflugia elegans Penard, 1890                    x
Difflugia globulosa (Dujardin, 1837)
Penard, 1902 *
Difflugia gramen Penard, 1902                     x          x
Difflugia lacustris (Penard, 1899)
Difflugia lithophila (Penard, 1902)               x
  Gauthier-Lievre et Thomas, 1958
Difflugia lobostoma Leidy 1879                    x
Difflugia penardi Hopkinson, 1909                 x          x
Difflugia cf. pulex Penard, 1902 *
Difflugia urceolata Carter, 1864                             x
Lesquereusia modesta Rhumbler, 1895 *             x
Netzelia tuberculata (Wallich, 1864) *            x
Phryganella acropodia (Hertwig et Lesser,
  1874) Hopkinson, 1909 *
cf. Trigonopyxis sp. *
Zivkovicia cf. spectabilis (Penard, 1902) *

Phylum Ciliophora
Ciliophora indet.                                 x          x

Phylum Cercozoa
Class Imbricatea
Cyphoderia ampulla (Ehrenberg, 1840)              x
  Leidy, 1879
Psammonobiotus communis Golemansky, 1967

Phylum Foraminifera
Class Monothalamea
cf. Allogromia sp. *

Phylum Platyhelminthes
Class Rhabditophora
Rhabditophora indet.                              x          x

Phylum Gastrotricha
Chaetonotidae gen. et spp. indet.                            x
Chaetonotus sp.

Phylum Rotifera
Class Bdelloidea
Bdelloidea gen. et spp. indet.                    x          x
Philodina roseola Ehrenberg, 1832 *
Class Monogononta
Cephalodella catellina (Muller, 1786)                        x
Cephalodella elegans Myers, 1924                  x
Cephalodella forficula (Ehrenberg, 1838)          x          x
Cephalodella gibba (Ehrenberg, 1830)              x          x
Cephalodella gracilis (Ehrenberg, 1830)                      x
Cephalodella intuta Myers, 1924                   x          x
Cephalodella labiosa Wulfert, 1940 *                         x
Cephalodella limosa Wulfert, 1937                            x
Cephalodella megalocephala (Glascott,             x          x
  1893)
Cephalodella tenuiseta (Burn, 1890)               x          x
Cephalodella spp.                                 x
Colurella adriatica Ehrenberg, 1831                          x
Colurella colurus (Ehrenberg, 1830)               x          x
Colurella dicentra (Gosse, 1887)                  x
Colurella geophila Donner, 1951
Colurella hindenburgi Steinecke, 1916
Colurella marinovi Althaus, 1957
Dicranophorus capucinus Harring et                x          x
  Myers, 1928
Dicranophorus hercules Wiszniewski,               x          x
  1932
Dicranophorus leptodon Wiszniewski,               x
  1934 *
Dicranophorus semnus Harring et Myers,            x
  1928 *
Dicranophorus sigmoides Wulfert, 1950                        x
Elosa spinifera Wiszniewski, 1932
Elosa worrallii Lord, 1891 *
Encentrum belluinum Harring et Myers,
  1928
Encentrum boreale Harring et Myers, 1928
Encentrum limicola Otto, 1936
Encentrum marinum (Dujardin, 1841)
Encentrum matthesi Remane, 1949
Encentrum rousseleti (Lie-Pettersen, 1905)        x
Encentrum uncinatum (Milne, 1886)                 x
Euchlanis dilatata Ehrenberg, 1832                           x
Gastropus stylifer Imhof, 1891                               x
Keratella cochlearis (Gosse, 1851)                           x
Keratella cruciformis (Thompson, 1892)
Keratella hiemalis Carlin, 1943                   x          x
Keratella quadrata (Muller, 1786)
Lecane bulla (Gosse, 1851)                                   x
Lecane closterocerca (Schmarda, 1859)             x          x
Lecane doryssa Harring, 1914 *
Lecane flexilis (Gosse, 1886)                     x          x
Lecane galeata (Bryce, 1892)                      x          x
Lecane hamata (Stokes, 1896)                                 x
Lecane luna (Muller, 1776)                                   x
Lecane nana (Murray, 1913)
Lecane perpusilla (Hauer, 1929)                              x
Lecane psammophila (Wiszniewski, 1932)            x          x
Lecane punctata (Murray, 1913)                    x          x
Lecane pusilla Harring, 1914
Lecane scutata (Harring et Myers, 1926) *         x          x
Lecane stenroosi (Meissner, 1908)
Lecane subulata (Harring et Myers, 1926)                     x
Lepadella ovalis (Muller, 1786)                   x          x
Lepadella patella (Muller, 1773)                  x          x
Lindia torulosa Dujardin, 1841
Monommata sp. *
Mytilina mucronata (Muller, 1773)                            x
Notholca squamula (Muller, 1786)                  x          x
Notommata cyrtopus Gosse, 1886                               x
Notommata cf. doneta Harring et Myers,
  1924
Notommata stitista Myers, 1937                    x
Pleurata vernalis (Wulfert, 1935) *
Polyarthra dolichoptera Idelson, 1925             x
Polyarthra luminosa Kutikova, 1962
Polyarthra remata Skorikov, 1896
Proales globulifera (Hauer, 1921)
Proales halophila Remane, 1929
Proales reinhardti (Ehrenberg, 1834)
Proales theodora (Gosse, 1887)
Proales spp.                                      x
Proalinopsis caudatus (Collins, 1872)
Synchaeta cecilia Rousselet, 1902
Synchaeta tremula (Muller, 1786)
Trichocerca dixonnuttalli (Jennings, 1903)        x          x
Trichocerca intermedia (Stenroos, 1898)           x          x
Trichocerca obtusidens (Olofsson, 1918)                      x
Trichocerca rousseleti (Voigt, 1902)                         x
Trichocerca similis (Wierzejski, 1893)                       x
Trichocerca tenuidens (Hauer, 1931) *                        x
Trichocerca tenuior (Gosse, 1886)                 x          x
Trichotria pocillum (Muller, 1776)                           x
Trichotria truncata (Whitelegge, 1889)
Wierzejskiella sabulosa (Wiszniewski,             x
  1932)
Wierzejskiella velox (Wiszniewski, 1932)          x          x
Wigrella depressa Wiszniewski, 1932 *             x          x

Phylum Annelida
Class Polychaeta
Hediste diversicolor (Muller, 1776)
Polychaeta juv.
Class Clitellata
Clitellata indet.                                 x
Chaetogaster diastrophus (Gruithuisen,                       x
  1828)
Chaetogaster setosus (Svetlov, 1925)                         x
Chaetogaster sp.                                             x
Lumbricillus lineatus (Muller, 1774)
Marionina sp.
Nais elinguis Muller, 1774
Paranais litoralis (Muller, 1780)
Tubificidae juv.                                             x

Phylum Mollusca
Class Bivalvia
Bivalvia juv.                                                x

Phylum Nematoda
Nematoda indet.                                   x          x
Class Adenophorea
Leptolaimidae indet.                              x
Prochromadora sp. *
Microlaimus sp.
Enoplida indet.                                              x
Enoplolaimus sp. *
Amphimonhystera sp. *
Linhystera sp. *
Retrotheristus sp. *
Valvaelaimus sp. *

Phylum Tardigrada
Class Eutardigrada
Milnesium sp.                                     x          x
Class Heterotardigrada
Oreella sp.

Phylum Arthropoda
Subphylum Chelicerata
Class Arachnida
Arachnida indet.                                  x          x
Subphylum Tetraconata
Class Maxillopoda
Harpacticoida gen. et spp. indet.                 x          x
Harpacticus uniremis Krayer, 1842                            x
Parastenocaris brevipes Kessler, 1913                        x
Mesocyclops leukarti (Claus, 1857)                           x
Cyclopidae juv.                                   x          x
Nauplii indet.
Class Branchiopoda
Alona sp.
Chydorus sphaericus (Muller, 1776)                x          x
Peracantha truncata (Muller, 1785)                           x
Class Ostracoda
Ostracoda indet.                                             x
Class Insecta
Ephemeroptera indet.                                         x
Diptera juv.                                      x          x
Number of taxa: 156                              65          81

Taxon                                         Verevi   Manniku   Nova

Phylum Amoebozoa
Class Lobosea
Order Arcellinida
Arcella sp.                                                       x
Arcella artocrea Leidy, 1876 *                  x
Arcella catinus Penard, 1890 *                  x
Arcella crenulata Deflandre, 1928 *             x
Arcella discoides Ehrenberg, 1843               x
Arcella hemisphaerica Perty, 1852                                 x
Centropyxis aerophila Deflandre, 1929           x                 x
Centropyxis aculeata (Ehrenberg, 1838)          x         x
Centropyxis cassis (Wallich, 1864)
Centropyxis constricta (Ehrenberg, 1841)        x
Centropyxis discoides Penard, 1902                                x
Centropyxis delicatula Penard, 1902 *           x
Centropyxis ecornis (Ehrenberg, 1841) *         x
Centropyxis hirsuta Deflandre, 1929 *           x
Centropyxis cf. laevigata Penard, 1890 *        x
Centropyxis orbicularis Deflandre, 1929 *       x         x
Centropyxis platystoma Penard, 1890
Cyclopyxis spp.                                                   x
Cyclopyxis arcelloides (Penard, 1902)
Cyclopyxis eurystoma Deflandre, 1929 *          x
Cyclopyxis kahli (Deflandre, 1929) *            x
Difflugia amphora (Leidy, 1874) Penard,
  1902
Difflugia bidens Penard, 1902
Difflugia brevicolla Cash et Hopkinson,
  1909 *
Difflugia elegans Penard, 1890                  x                 x
Difflugia globulosa (Dujardin, 1837)            x
Penard, 1902 *
Difflugia gramen Penard, 1902
Difflugia lacustris (Penard, 1899)                                x
Difflugia lithophila (Penard, 1902)             x
  Gauthier-Lievre et Thomas, 1958
Difflugia lobostoma Leidy 1879                  x
Difflugia penardi Hopkinson, 1909               x                 x
Difflugia cf. pulex Penard, 1902 *              x
Difflugia urceolata Carter, 1864                                  x
Lesquereusia modesta Rhumbler, 1895 *
Netzelia tuberculata (Wallich, 1864) *          x
Phryganella acropodia (Hertwig et Lesser,       x                 x
  1874) Hopkinson, 1909 *
cf. Trigonopyxis sp. *                          x
Zivkovicia cf. spectabilis (Penard, 1902) *                       x

Phylum Ciliophora
Ciliophora indet.                               x         x       x

Phylum Cercozoa
Class Imbricatea
Cyphoderia ampulla (Ehrenberg, 1840)                      x       x
  Leidy, 1879
Psammonobiotus communis Golemansky, 1967                          x

Phylum Foraminifera
Class Monothalamea
cf. Allogromia sp. *                                              x

Phylum Platyhelminthes
Class Rhabditophora
Rhabditophora indet.                                      x       x

Phylum Gastrotricha
Chaetonotidae gen. et spp. indet.                                 x
Chaetonotus sp.                                           x

Phylum Rotifera
Class Bdelloidea
Bdelloidea gen. et spp. indet.                  x                 x
Philodina roseola Ehrenberg, 1832 *             x
Class Monogononta
Cephalodella catellina (Muller, 1786)
Cephalodella elegans Myers, 1924
Cephalodella forficula (Ehrenberg, 1838)
Cephalodella gibba (Ehrenberg, 1830)
Cephalodella gracilis (Ehrenberg, 1830)
Cephalodella intuta Myers, 1924
Cephalodella labiosa Wulfert, 1940 *
Cephalodella limosa Wulfert, 1937
Cephalodella megalocephala (Glascott,
  1893)
Cephalodella tenuiseta (Burn, 1890)
Cephalodella spp.
Colurella adriatica Ehrenberg, 1831                       x       x
Colurella colurus (Ehrenberg, 1830)                               x
Colurella dicentra (Gosse, 1887)                                  x
Colurella geophila Donner, 1951                                   x
Colurella hindenburgi Steinecke, 1916                             x
Colurella marinovi Althaus, 1957                                  x
Dicranophorus capucinus Harring et
  Myers, 1928
Dicranophorus hercules Wiszniewski,
  1932
Dicranophorus leptodon Wiszniewski,
  1934 *
Dicranophorus semnus Harring et Myers,
  1928 *
Dicranophorus sigmoides Wulfert, 1950
Elosa spinifera Wiszniewski, 1932                         x
Elosa worrallii Lord, 1891 *                              x
Encentrum belluinum Harring et Myers,                             x
  1928
Encentrum boreale Harring et Myers, 1928                          x
Encentrum limicola Otto, 1936                                     x
Encentrum marinum (Dujardin, 1841)                                x
Encentrum matthesi Remane, 1949                                   x
Encentrum rousseleti (Lie-Pettersen, 1905)
Encentrum uncinatum (Milne, 1886)
Euchlanis dilatata Ehrenberg, 1832
Gastropus stylifer Imhof, 1891                            x
Keratella cochlearis (Gosse, 1851)              x         x
Keratella cruciformis (Thompson, 1892)                            x
Keratella hiemalis Carlin, 1943
Keratella quadrata (Muller, 1786)                                 x
Lecane bulla (Gosse, 1851)
Lecane closterocerca (Schmarda, 1859)           x         x
Lecane doryssa Harring, 1914 *                  x
Lecane flexilis (Gosse, 1886)                   x
Lecane galeata (Bryce, 1892)
Lecane hamata (Stokes, 1896)                    x
Lecane luna (Muller, 1776)                      x                 x
Lecane nana (Murray, 1913)
Lecane perpusilla (Hauer, 1929)
Lecane psammophila (Wiszniewski, 1932)
Lecane punctata (Murray, 1913)
Lecane pusilla Harring, 1914                    x                 x
Lecane scutata (Harring et Myers, 1926) *                 x
Lecane stenroosi (Meissner, 1908)               x
Lecane subulata (Harring et Myers, 1926)                  x
Lepadella ovalis (Muller, 1786)
Lepadella patella (Muller, 1773)                x         x
Lindia torulosa Dujardin, 1841                  x                 x
Monommata sp. *                                 x
Mytilina mucronata (Muller, 1773)
Notholca squamula (Muller, 1786)                                  x
Notommata cyrtopus Gosse, 1886
Notommata cf. doneta Harring et Myers,
  1924
Notommata stitista Myers, 1937
Pleurata vernalis (Wulfert, 1935) *                       x
Polyarthra dolichoptera Idelson, 1925
Polyarthra luminosa Kutikova, 1962                        x
Polyarthra remata Skorikov, 1896                          x
Proales globulifera (Hauer, 1921)                                 x
Proales halophila Remane, 1929                                    x
Proales reinhardti (Ehrenberg, 1834)                              x
Proales theodora (Gosse, 1887)                                    x
Proales spp.
Proalinopsis caudatus (Collins, 1872)
Synchaeta cecilia Rousselet, 1902                                 x
Synchaeta tremula (Muller, 1786)
Trichocerca dixonnuttalli (Jennings, 1903)                        x
Trichocerca intermedia (Stenroos, 1898)
Trichocerca obtusidens (Olofsson, 1918)
Trichocerca rousseleti (Voigt, 1902)
Trichocerca similis (Wierzejski, 1893)                            x
Trichocerca tenuidens (Hauer, 1931) *
Trichocerca tenuior (Gosse, 1886)                                 x
Trichotria pocillum (Muller, 1776)
Trichotria truncata (Whitelegge, 1889)
Wierzejskiella sabulosa (Wiszniewski,
  1932)
Wierzejskiella velox (Wiszniewski, 1932)
Wigrella depressa Wiszniewski, 1932 *

Phylum Annelida
Class Polychaeta
Hediste diversicolor (Muller, 1776)                               x
Polychaeta juv.                                                   x
Class Clitellata
Clitellata indet.                                         x
Chaetogaster diastrophus (Gruithuisen,
  1828)
Chaetogaster setosus (Svetlov, 1925)
Chaetogaster sp.
Lumbricillus lineatus (Muller, 1774)                              x
Marionina sp.                                                     x
Nais elinguis Muller, 1774                                        x
Paranais litoralis (Muller, 1780)
Tubificidae juv.

Phylum Mollusca
Class Bivalvia
Bivalvia juv.

Phylum Nematoda
Nematoda indet.                                 x         x       x
Class Adenophorea
Leptolaimidae indet.
Prochromadora sp. *                                               x
Microlaimus sp.                                                   x
Enoplida indet.
Enoplolaimus sp. *
Amphimonhystera sp. *
Linhystera sp. *                                                  x
Retrotheristus sp. *                                              x
Valvaelaimus sp. *                                                x

Phylum Tardigrada
Class Eutardigrada
Milnesium sp.                                             x
Class Heterotardigrada
Oreella sp.                                                       x

Phylum Arthropoda
Subphylum Chelicerata
Class Arachnida
Arachnida indet.                                                  x
Subphylum Tetraconata
Class Maxillopoda
Harpacticoida gen. et spp. indet.                         x       x
Harpacticus uniremis Krayer, 1842                                 x
Parastenocaris brevipes Kessler, 1913                     x       x
Mesocyclops leukarti (Claus, 1857)
Cyclopidae juv.
Nauplii indet.                                  x         x       x
Class Branchiopoda
Alona sp.                                       x
Chydorus sphaericus (Muller, 1776)
Peracantha truncata (Muller, 1785)
Class Ostracoda
Ostracoda indet.                                x         x
Class Insecta
Ephemeroptera indet.
Diptera juv.                                    x                 x
Number of taxa: 156                             42       25       61

Taxon                                         Pirita   Narva-Joesuu

Phylum Amoebozoa
Class Lobosea
Order Arcellinida
Arcella sp.                                     x
Arcella artocrea Leidy, 1876 *
Arcella catinus Penard, 1890 *
Arcella crenulata Deflandre, 1928 *
Arcella discoides Ehrenberg, 1843
Arcella hemisphaerica Perty, 1852               x
Centropyxis aerophila Deflandre, 1929                       x
Centropyxis aculeata (Ehrenberg, 1838)
Centropyxis cassis (Wallich, 1864)
Centropyxis constricta (Ehrenberg, 1841)
Centropyxis discoides Penard, 1902
Centropyxis delicatula Penard, 1902 *
Centropyxis ecornis (Ehrenberg, 1841) *
Centropyxis hirsuta Deflandre, 1929 *
Centropyxis cf. laevigata Penard, 1890 *
Centropyxis orbicularis Deflandre, 1929 *
Centropyxis platystoma Penard, 1890
Cyclopyxis spp.                                 x           x
Cyclopyxis arcelloides (Penard, 1902)
Cyclopyxis eurystoma Deflandre, 1929 *
Cyclopyxis kahli (Deflandre, 1929) *
Difflugia amphora (Leidy, 1874) Penard,                     x
  1902
Difflugia bidens Penard, 1902
Difflugia brevicolla Cash et Hopkinson,
  1909 *
Difflugia elegans Penard, 1890
Difflugia globulosa (Dujardin, 1837)
Penard, 1902 *
Difflugia gramen Penard, 1902
Difflugia lacustris (Penard, 1899)              x           x
Difflugia lithophila (Penard, 1902)
  Gauthier-Lievre et Thomas, 1958
Difflugia lobostoma Leidy 1879
Difflugia penardi Hopkinson, 1909
Difflugia cf. pulex Penard, 1902 *
Difflugia urceolata Carter, 1864                            x
Lesquereusia modesta Rhumbler, 1895 *
Netzelia tuberculata (Wallich, 1864) *
Phryganella acropodia (Hertwig et Lesser,
  1874) Hopkinson, 1909 *
cf. Trigonopyxis sp. *
Zivkovicia cf. spectabilis (Penard, 1902) *

Phylum Ciliophora
Ciliophora indet.                               x           x

Phylum Cercozoa
Class Imbricatea
Cyphoderia ampulla (Ehrenberg, 1840)                        x
  Leidy, 1879
Psammonobiotus communis Golemansky, 1967

Phylum Foraminifera
Class Monothalamea
cf. Allogromia sp. *

Phylum Platyhelminthes
Class Rhabditophora
Rhabditophora indet.                            x           x

Phylum Gastrotricha
Chaetonotidae gen. et spp. indet.               x           x
Chaetonotus sp.

Phylum Rotifera
Class Bdelloidea
Bdelloidea gen. et spp. indet.                  x           x
Philodina roseola Ehrenberg, 1832 *
Class Monogononta
Cephalodella catellina (Muller, 1786)
Cephalodella elegans Myers, 1924
Cephalodella forficula (Ehrenberg, 1838)
Cephalodella gibba (Ehrenberg, 1830)
Cephalodella gracilis (Ehrenberg, 1830)
Cephalodella intuta Myers, 1924
Cephalodella labiosa Wulfert, 1940 *
Cephalodella limosa Wulfert, 1937
Cephalodella megalocephala (Glascott,
  1893)
Cephalodella tenuiseta (Burn, 1890)
Cephalodella spp.                                           x
Colurella adriatica Ehrenberg, 1831
Colurella colurus (Ehrenberg, 1830)             x
Colurella dicentra (Gosse, 1887)
Colurella geophila Donner, 1951
Colurella hindenburgi Steinecke, 1916                       x
Colurella marinovi Althaus, 1957                            x
Dicranophorus capucinus Harring et
  Myers, 1928
Dicranophorus hercules Wiszniewski,
  1932
Dicranophorus leptodon Wiszniewski,
  1934 *
Dicranophorus semnus Harring et Myers,
  1928 *
Dicranophorus sigmoides Wulfert, 1950
Elosa spinifera Wiszniewski, 1932
Elosa worrallii Lord, 1891 *
Encentrum belluinum Harring et Myers,           x           x
  1928
Encentrum boreale Harring et Myers, 1928        x           x
Encentrum limicola Otto, 1936
Encentrum marinum (Dujardin, 1841)              x           x
Encentrum matthesi Remane, 1949                             x
Encentrum rousseleti (Lie-Pettersen, 1905)
Encentrum uncinatum (Milne, 1886)
Euchlanis dilatata Ehrenberg, 1832
Gastropus stylifer Imhof, 1891
Keratella cochlearis (Gosse, 1851)              x           x
Keratella cruciformis (Thompson, 1892)
Keratella hiemalis Carlin, 1943
Keratella quadrata (Muller, 1786)               x
Lecane bulla (Gosse, 1851)
Lecane closterocerca (Schmarda, 1859)
Lecane doryssa Harring, 1914 *
Lecane flexilis (Gosse, 1886)
Lecane galeata (Bryce, 1892)
Lecane hamata (Stokes, 1896)
Lecane luna (Muller, 1776)
Lecane nana (Murray, 1913)                                  x
Lecane perpusilla (Hauer, 1929)
Lecane psammophila (Wiszniewski, 1932)                      x
Lecane punctata (Murray, 1913)
Lecane pusilla Harring, 1914
Lecane scutata (Harring et Myers, 1926) *
Lecane stenroosi (Meissner, 1908)
Lecane subulata (Harring et Myers, 1926)
Lepadella ovalis (Muller, 1786)
Lepadella patella (Muller, 1773)
Lindia torulosa Dujardin, 1841                              x
Monommata sp. *
Mytilina mucronata (Muller, 1773)
Notholca squamula (Muller, 1786)
Notommata cyrtopus Gosse, 1886
Notommata cf. doneta Harring et Myers,          x
  1924
Notommata stitista Myers, 1937
Pleurata vernalis (Wulfert, 1935) *
Polyarthra dolichoptera Idelson, 1925
Polyarthra luminosa Kutikova, 1962
Polyarthra remata Skorikov, 1896
Proales globulifera (Hauer, 1921)               x           x
Proales halophila Remane, 1929                  x           x
Proales reinhardti (Ehrenberg, 1834)            x           x
Proales theodora (Gosse, 1887)                  x           x
Proales spp.                                    x
Proalinopsis caudatus (Collins, 1872)           x           x
Synchaeta cecilia Rousselet, 1902                           x
Synchaeta tremula (Muller, 1786)                            x
Trichocerca dixonnuttalli (Jennings, 1903)      x           x
Trichocerca intermedia (Stenroos, 1898)
Trichocerca obtusidens (Olofsson, 1918)
Trichocerca rousseleti (Voigt, 1902)
Trichocerca similis (Wierzejski, 1893)                      x
Trichocerca tenuidens (Hauer, 1931) *
Trichocerca tenuior (Gosse, 1886)                           x
Trichotria pocillum (Muller, 1776)
Trichotria truncata (Whitelegge, 1889)                      x
Wierzejskiella sabulosa (Wiszniewski,                       x
  1932)
Wierzejskiella velox (Wiszniewski, 1932)
Wigrella depressa Wiszniewski, 1932 *

Phylum Annelida
Class Polychaeta
Hediste diversicolor (Muller, 1776)
Polychaeta juv.                                             x
Class Clitellata
Clitellata indet.
Chaetogaster diastrophus (Gruithuisen,
  1828)
Chaetogaster setosus (Svetlov, 1925)
Chaetogaster sp.
Lumbricillus lineatus (Muller, 1774)
Marionina sp.                                   x           x
Nais elinguis Muller, 1774                                  x
Paranais litoralis (Muller, 1780)               x
Tubificidae juv.

Phylum Mollusca
Class Bivalvia
Bivalvia juv.

Phylum Nematoda
Nematoda indet.                                 x           x
Class Adenophorea
Leptolaimidae indet.
Prochromadora sp. *
Microlaimus sp.
Enoplida indet.
Enoplolaimus sp. *                              x
Amphimonhystera sp. *                           x
Linhystera sp. *                                x           x
Retrotheristus sp. *
Valvaelaimus sp. *

Phylum Tardigrada
Class Eutardigrada
Milnesium sp.
Class Heterotardigrada
Oreella sp.                                                 x

Phylum Arthropoda
Subphylum Chelicerata
Class Arachnida
Arachnida indet.
Subphylum Tetraconata
Class Maxillopoda
Harpacticoida gen. et spp. indet.               x           x
Harpacticus uniremis Krayer, 1842
Parastenocaris brevipes Kessler, 1913
Mesocyclops leukarti (Claus, 1857)
Cyclopidae juv.
Nauplii indet.                                  x           x
Class Branchiopoda
Alona sp.
Chydorus sphaericus (Muller, 1776)
Peracantha truncata (Muller, 1785)
Class Ostracoda
Ostracoda indet.                                x
Class Insecta
Ephemeroptera indet.
Diptera juv.                                    x           x
Number of taxa: 156                             32          42

Table 3. Sorensen similarity coefficient between the studied areas

                            All taxa          Only    Only testate
                                       rotifer taxa   amoebae taxa

Vortsjarv vs Saadjarv         0.566          0.590          0.606
Vortsjarv vs Verevi           0.374          0.170          0.619
Saadjarv vs Verevi            0.279          0.246          0.324
Vortsjarv vs Nova             0.238          0.200          0.194
Vortsjarv vs Pirita           0.186          0.163          0.000
Vortsjarv vs Narva-Joesuu     0.243          0.207          0.083
Saadjarv vs Nova              0.298          0.229          0.308
Saadjarv vs Pirita            0.214          0.136          0.111
Saadjarv vs Narva-Joesuu      0.230          0.176          0.211
Verevi vs Nova                0.233          0.205          0.229
Verevi vs Pirita              0.189          0.143          0.000
Verevi vs Narva-Joesuu        0.190          0.162          0.071
Nova vs Pirita                0.516          0.537          0.500
Nova vs Narva-Joesuu          0.641          0.640          0.471
Pirita vs Narva-Joesuu        0.595          0.564          0.444
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Article Details
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Author:Lokko, Kulli; Virro, Taavi; Kotta, Jonne
Publication:Estonian Journal of Ecology
Article Type:Report
Geographic Code:4EXES
Date:Dec 1, 2014
Words:7958
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