Diversity and Structure of Pelagic Zooplankton (Crustacea, Rotifera) in NE Poland

This study presents the diversity and structure of pelagic zooplankton in north-eastern Poland. The research was conducted in 47 lakes with different trophic conditions in the middle of summer. Samples were collected close to the deepest part of the lakes to avoid the diverse benthic and littoral zones. We found 119 zooplankton species of which 32 were Cladocera, 16 were Cyclopoida, 4 were Calanoida, and 67 were Rotifera. We determined which species occurred most frequently in the region, as well as the species that were characteristic of different trophic conditions. We also recorded the presence of eight cold-adapted species which some of them are considered as glacial relicts (e.g., Eurytemora lacustris, Heterocope appendiculata, Cyclops lacustris). Our research revealed potential glacial refugia for planktonic species in 14 lakes of NE Poland. Our study suggests that the presence of stenotherm species may be an excellent indicator of the ecological status of deep lakes and could be considered in lake monitoring programs. Furthermore, we did not find Bythotrephes longimanus which has been reported from Poland. Instead, we found that B. brevimanus was the most common representative of the genus in the study area

Influence of environmental factors on vertical distribution of zooplankton communities in humic lakes

The influence of vertical environmental gradients on zooplankton communities was studied in five humic lakes with the high availability of food resources (phytoplankton and bacterioplankton) and low fish pressure. The factors that inhibit the development of large zooplankton in humic lakes are currently widely debated. We have found that relatively productive humic lakes do not offer many niches for zooplankton because of the sharp thermal gradient which results in a shallow layer of oxygenated waters. The results of this study indicated that different taxonomic groups of zooplankton are determined by a different set of environmental variables. This phenomenon explains very low species richness of zooplankton and a possibility of their coexistence in the narrow oxygenated layer. We concluded that due to sharp thermal gradient in humic lakes biomass of herbivores may be reduced which could promote development of phytoplankton.Studies in five productive humic lakes of low fish pressure indicated that taxonomic groups of zooplankton are determined by a different set of environmental variables, which explains very low species richness of zooplankton. Due to sharp thermal gradient in the lakes biomass of herbivores is reduced which promotes development of phytoplankton

Rotifers of Inter-Forest Springs

Springs are often considered as “hotspots” of aquatic biodiversity. However, small organisms, such as rotifers, substantially contribute to secondary production, but they are rarely investigated in springs. We surveyed the rotifer fauna of 47 springs in the Knyszyn Forest (north-eastern Poland) in summer and autumn 2014–2015. We hypothesized that stream communities of Rotifera may be specific to this habitat. Rotifer samples were taken using a Plexiglas tube in the spring current. Concurrently, water temperature, pH, conductivity, water redox potential and phosphorus and nitrogen concentrations were determined. The springs did not differ statistically in water quality and were stable regarding their temperature and conductivity. Rotifer densities and mean number of monogonont species were very low both in summer and autumn. Nevertheless, the total number of species recorded in all springs was relatively high and accounted for 101 in total. Although strongly differentiated, the rotifer fauna contained a set of several species common to most of the springs. Most of the recorded species are eurytopic and widely spread in water ecosystems. Only the concentration of magnesium and chloride ions had an impact on Monogononta numbers

Rotifers of Inter-Forest Springs

Springs are often considered as “hotspots” of aquatic biodiversity. However, small organisms, such as rotifers, substantially contribute to secondary production, but they are rarely investigated in springs. We surveyed the rotifer fauna of 47 springs in the Knyszyn Forest (north-eastern Poland) in summer and autumn 2014–2015. We hypothesized that stream communities of Rotifera may be specific to this habitat. Rotifer samples were taken using a Plexiglas tube in the spring current. Concurrently, water temperature, pH, conductivity, water redox potential and phosphorus and nitrogen concentrations were determined. The springs did not differ statistically in water quality and were stable regarding their temperature and conductivity. Rotifer densities and mean number of monogonont species were very low both in summer and autumn. Nevertheless, the total number of species recorded in all springs was relatively high and accounted for 101 in total. Although strongly differentiated, the rotifer fauna contained a set of several species common to most of the springs. Most of the recorded species are eurytopic and widely spread in water ecosystems. Only the concentration of magnesium and chloride ions had an impact on Monogononta numbers

Epizoic Rotifers and Microcrustaceans on Bivalves of Different Size and Behavior

Previous mesocosm experiments with the epizoon of Dreissena polymorpha revealed that the communities of Rotifera and Crustacea were much more abundant and had higher species richness than epizoon of Unio tumidus in nature. These differences could be attributed to different environmental conditions and/or different host behavior. To test this hypothesis, we compared epizoon of D.polymorpha and U.tumidus placed in identical mesocosm conditions, in which Unio could not move vertically due to the lack of sediments. Half of the mesocosms contained D. polymorpha, the other half comprised U. tumidus. Each species of mollusks was kept in the mesocosms with eutrophic and mesotrophic conditions. Finally, we established four treatments that were replicated in triplicate mesocosms. Mesocosm experiments showed that epizoon communities of U. tumidus were even more abundant than that of D. polymorpha and their species richness was similar. Therefore, we concluded that previously revealed strong differences between epizoon communities of D. polymorpha and U. tumidus were related to the different environmental conditions and bivalve behavior

Diversity of rotifer communities in lakes of the Suwalki Landscape Park

Studies of summer rotifer fauna of 11 shallow and 6 deep lakes of the Suwałki Landscape Park were conducted in an aim to assess the role of lake depth and biotic and abiotic factors in determining the diversity of rotifer communities in lakes undergoing a natural rate of eutrophication not accelerated by anthropopression. Some differences were observed when the group of shallow lakes was compared with that of deep lakes. The former were more differentiated as regards a list of rotifer species, partly due to the high proportion of species with low frequency. Consequently, their faunal originality was markedly higher and values of the percentage similarity of rotifer communities were much lower than in deep lakes. Species richness of rotifer fauna was also dependent on the trophic state of the studied lakes, the character of a nutrient limiting primary production, as well as biomass of diatoms and green algae

Wrotki (Rotifera, Bdelloidea)

Wydawnictwo seryjne Fauna Słodkowodna Polski istnieje od 1935 roku. Dotychczas opublikowało 21 zeszytów poświęconych zarówno zwierzętom bezkręgowym (lnvertebrata), jak i kręgowcom (Vertebrata). Kolejne tomy FSP zawierają bogate dane ogólne dotyczące omawianej grupy zwierzęcej oraz informacje szczegółowe o określonych gatunkach, rodzajach, rodzinach i rzędach. Integralną część każdego opracowania stanowią też klucze do oznaczania taksonów. Dzięki takiemu ujęciu monografie poszczególnych grup systematycznych stanowią kompendium najnowszej wiedzy teoretycznej i praktycznej na ich temat. Zeszyty FSP przygotowują wybitni specjaliści w zakresie znajomości fauny Polski. Tom 32C, autorstwa dr hab. Ireny Bielańskiej-Grajner z Uniwersytetu Śląskiego w Katowicach, prof. dr hab. Jolanty Ejsmont-Karabin z Uniwersytetu w Białymstoku i dr Natalii Iakovenko z Narodowej Akademii Nauk Ukrainy w Kijowie i Uniwersytetu Ostrawskiego (Czechy), poświęcony krajowym wrotkom (Rotifera) z podgromady Bdelloidea, omawia szczegółowo anatomię, biologię, ekologię i taksonomię tych zwierząt oraz dostarcza wskazówek praktycznych dotyczących metodyki badań. Zawiera również klucze do oznaczania żyjących w wodach śródlądowych Polski przedstawicieli Bdelloidea (do szczebla rodzaju) oraz atlas umożliwiający identyfikację gatunków.Publikacja dofinansowana ze środków Ministra Nauki i Szkolnictwa Wyższego; Udostępnienie publikacji Wydawnictwa Uniwersytetu Łódzkiego finansowane w ramach projektu „Doskonałość naukowa kluczem do doskonałości kształcenia”. Projekt realizowany jest ze środków Europejskiego Funduszu Społecznego w ramach Programu Operacyjnego Wiedza Edukacja Rozwój; nr umowy: POWER.03.05.00-00-Z092/17-00

Long-term changes in the trophic state of Suwalki lakes – an analysis by means of indices based on abundance and composition of their rotifer fauna

Rotifer abundance and species composition in lakes of the Suwalki Landscape Park were studied in the years 1983–1985, 2009, 2012 and 2015. Rotifer trophic state indices (TSIROT) were used to assess changes in the trophic state of the studied lakes. In most lakes of the Suwalki Landscape Park, there were no changes in rotifer communities over the 25–32 year period to indicate a decline in trophy of the lakes. However, in lakes with the strongest decline in TSIROT values, the values of indicative parameters widely varied in 2015, which may indicate that the status of rotifer communities in the lakes may be dependent on non-trophic factors