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Unusual stable morphotype of acroperus harpae (Baird, 1834) from Lake Mỳvatn, Iceland (Cladocera: Anomopoda: Chydoridae) revealed by palaeolimnological studies

Siney A Y, Zawisza E, Einarsson A

Studia Quaternaria

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2012

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Vol. 29

3--7

EN

A new unusual morphotype of Acroperus harpae (Baird, 1834) was found in Lake Mỳvatn and its neighbouring Lake Budlungaflói in Iceland. This form, A. harpae f. multidentata is characterized by a very large head keel and by 5-9 denticles on the posterovental angle of the valves instead of 1-3 common for A. harpae. The new form did not differ from typical A. harpae in the morphology of the postabdomen, head pores or any appendages. A study of Lake Mỳvatn sediments reveled that this form existed in the lake for at least two thousand years.

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Late-Glacial cladoceran succession in three lakes of the Chełm Hills Region (Łęczna-Włodawa Lake Group, SE Poland)

Suchora M.

Studia Quaternaria

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2012

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Vol. 29

9--21

EN

High resotution studtes on subfossil Cladocera from three closely located lakes of the Chełm Hills Region - Lake Słone, Syczyńskie, and Pniówno, evidenced a strong zooplankton response to the well-known climatic changes of the Late-Glacial and early-Holocene. The general changes in the cladoceran community structure resemble those described from other Polish and European lakes. Certain important differences were identified, however, which can be attributed to the peculiarity of the environmental conditions of the region, regarding: the deep character of the lakes studied already in the initial phase of their development (Older Dryas), an intensive eutrophication process induced by the Allerӧd climate warming with a periodical lowering of the trophic status, and the character of the Younger Dryas coollng less severe than in some other regions. The chronology of the palaeoenvironmental changes identified by means of subfossil Cladocera analysis was based on the results of palaeobotanical analysis, and confirmed by radiocarbon dating available for two profiles. Taking advantage of the close location of the study sites, their morphometric and geological similarities, and the high resolution of sampling, an attempt was made to use cladoceran succession in order to establish the stratigraphic division for Lake Pniówno, lacking palynological and radiocarbon data.

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Distribution of Cladocera communities across a climate gradient in shallow lakes from Croatia to Hungary: a preliminary study

Kӧvér C, Korponai J, Katalinic A, Bereczki C

Studia Quaternaria

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2012

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Vol. 29

45--52

EN

Cladocera communities in surface sediments of seven lakes were sampled from the Mediterranean to north Hungary. Conductivity, pH, primary ions (Ca2+, Mg2+, Na+, K+, Cl-, SO42-, HCO3-, CO32-) and macrophyte coverage were measured as contributed environmental parameters for the distribution of cladoceran communities across the lakes. Thirtytwo cladoceran species were found in the seven lakes. The recorded species have wide tolerance spectra, and are able to colonize very different kind of habitats. The most common and abundant species were Chydorus sphaericus, Alona rectangula and Bosmina longirostris. Lake area, latitude, macrophyte coverage, pH, conductivity and hardness were found to be the most determinant environmental variables in the distribution of cladoceran species. This study revealed that although the lakes show a clear separation in environmental parameters the composition and distribution of Cladoceran communities differ only slightly across the investigated geographical gradient.

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Algal and invertebrate microfossil assemblages from lake sediments in the reconstruction of past community dynamics - preliminary information

Antipushina Z, Szeroczyńska K, Zawisza E.

Studia Quaternaria

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2012

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Vol. 29

53--58

EN

This paper focuses on the usefulness of a palaeolimnological method called the joint algological and zoological analysis. The joint algo-zoological analysis involves counting all identifiable remains of the main algae groups (Bacillario- phyta, Cyanophyta, Desmidiales, other Chlorophyta, Trachelomonas sp.) and invertebrate groups (Cladocera, Ostra- coda, Chironomidae, Chaoborus sp., and other insects, Turbellaria, Bryozoa, Spongia and Testacida) in volumetric samples. We present results from recent sediments of Lake Glubokoe (Moscow region, Russia) as an example of the application of this method. We reconstruct the structure of phytoplankton, zooplankton and zoobenthos communities and their dynamics over the last 25 years. Our results support the validity of this method in the reconstruction of the structure of phyto- and zooplankton communities and their dynamics, information that may be lost when carrying out separate analyses for individual groups. Simplicity is another advantage of this methodology.

5

500 years of ecological changes recorded in subfossil Cladocera in a high-altitude, tropical Lake Lago de la Luna, central Mexico

Zawisza E., Caballero M, Ruiz-Fernandez C

Studia Quaternaria

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2012

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Vol. 29

23--29

EN

We present the last 500 years of history of a high-altitude tropical lake Lago de la Luna located at Nevado de Toluca crater, Central Mexico, based on subfossil Cladocera analysis. Through the studied sedimentary sequence only five Cladocera species were present. Cladocera community was dominated by littoral species (4) and among them one (Ilyocryptus nevadensis) is endemic. The detailed analysis of the sediments (every 1 cm) allowed us to track contemporary climatic and anthropogenic changes. Our results showed that Lago de la Luna is a very sensitive ecosystem and has strong response to climatic changes. The most remarkable change in the Cladocera community was observed between 1683-1780 yr, which was well correlated with the Little Ice Age. PCA results implied that modern state of the lake Lago de la Luna is very similar to one 400-500 yr ago. Only one period was identified when human impact was of importance. This period seemed to correlate with changes in the lake ecosystem due to fish introduction in the 1950s.

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Description of the subfossil head shield of Alona protzi hartwig 1900 (anomopoda, chydoridae) and the environmental characteristics of its finding sites

Bjerring R., Nykanen M., Sarmaja-Korjonen K., Sinev A., Jensen K., Nevalainen L., Szeroczyńska K., Zawisza E.

Studia Quaternaria

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2008

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Vol. 25

47-53

EN

This paper gives a description of the head shield of Alona protzi, a rare species of Cladocera (water fleas) whose separated head shield has not yet been described in detail. Subfossil head shields of A. protzi were found in sediment cores taken from lakes in Denmark, Sweden, Finland, Estonia and Poland. Despite the rarity of the species this suggests a wide distribution of A. protzi in northern Europe. The ecology of A. protzi is poorly known. The environmental spectrum of the finding sites was wide and ranged from relatively nutrient poor clear water lakes to eutrophic turbid water lakes, indicating that A. protzi is not narrowly restricted. Most of the lakes were, however, meso-eutrophic with neutral to high pH, and with a relatively low abundance of submerged macrophytes. However, we cannot exclude the possibility that A. protzi mainly lives in groundwater and is only occasionally transported into lakes.

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The development history of Wigry Lake as shown by subfossil cladocera

Zawisza E., Szeroczyńska K.

Geochronometria

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2007

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Vol. 27

67-74

EN

Environmental changes in Wigry Lake during the Late Glacial and Holocene were studied on the basis of subfossil Cladocera analysis. Cladocera are present in a long core WZS/03 (Słupiańska Bay), and a surface sediments. The sediment contains remains of twenty-seven species belonging to 5 families. Species composition of plankton and the variability in the frequency of specimens of Cladocera made possible to distinguish five phases of their development, which well correlated with palynological phases. The correlation proves that the biological development of Wigry Lake was determined mainly by climatic changes. During the history of the lake, planktonic forms were dominant and represented by Bosminidae. It indicates that the lake was (excluding the initial part) deep and oligo- or mesotrophic. The mesotrophic state has been noted during the Atlantic chronozone and temporary. Taking into consideration the size and the depth as well as the rare human population around the lake it can be stated that the trophy rise was the result of the warm climate. It is also possible that during the last few decades the natural and anthropogenic factors could add. Probably mild winters, warm and long summers, increased tourists number were partly responsible for changes of water state.

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The significance of subfossil Cladocera in stratigraphy of Late Glacial and Holocene

Szeroczyńska K.

Studia Quaternaria

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2006

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Vol. 23

37-45

EN

This paper presents discussion on the results of subfossil Cladocera analyses from five lakes in Poland (Przedni Staw Lake, Perespilno Lake, Gościąż Lake, Imiołki- fossil lake and Ostrowite Lake). The Cladocera are represented in sediments by remains of planktonic (Bosminidae, Daphnidae) and littoral (Chydoridae) forms. Cladoceran assemblage phases ("ecostratigraphy") were determined on the basis of changes in dominance of indicator species and past ecological conditions were reconstructed. The results are being discussed from the viewpoint of climate change and anthropogenic activity and their role in the lake evolution. Moreover, an attempt to use the cladoceran phases for stratigraphic division of the Late Glacial and Holocene was made. During the Bolling/Allerod interstadial, distinguished on the basis of Pollen analysis, Cladocera indicated short phase of bad condition (dry or cold?), probably as the Old Dryas climate results. The beginning of Holocene are characterized, in mountain and lowland lakes, by high increase in the number of species and specimens of Cladocera. This described clear warming and marked the boundary Late Glacial/Holocene. It was indicated that the "ecostratigraphy" based on Cladocera can be useful for climatostratigraphy, if climate was the major factor controlling the development of freshwater lakes.

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Subfossil remains of Camptocercus lilljeborgii(anomopoda, chydoridae)

Sarmaja-Korjonen K.

Studia Quaternaria

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2005

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Vol. 22

37-39

EN

Subfossil remains of Camptocercus lilljeborgii were abundant in the sediments of a core taken from a presently paludified shore of Lake Väike Juusa, southern Estonia. This made it possible to identify and describe the subfossil remains of the taxon, especially headshields and shells. The remains resemble those of Camptocercus rectirostris but differ in details that make the identification easy. The headshield is stouter and more arched and has no surface sculpture. It can also be distinguished from headshields of Camptocercus fennicus and Acroperus harpae by shape. The shell is characterized by parallel blurred lines and teeth on the posterior-ventral angle. The postabdomen is elongate and narrow and has more than 20 teeth on the dorsal margins.

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Identification of subfossil remains of cladocerans Latona setifera, Diaphanosoma brachyurum AND Holopedium gibberum

Nevalainen L., Sarmaja-Korjonen K.

Studia Quaternaria

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2005

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Vol. 22

41-44

EN

The preservation of chitinous outer body parts of Cladocera is mostly selective, except in two families, the planktonic Bosminidae and the littoral Chydoridae. In addition, at least some body parts of several other genera and taxa preserze but many of them have not been widely identified. The aim of the article is to present photographs and line drawings of the postabdomen and the postabdominal claws of Holopedium gibberum, together with the postabdominal claws of Latona setifera and Diaphanosoma brachyurum for use of cladoceran analysts. In analysis of subfossil remains pictures and descriptions of separate body parts make the identification more reliable. It is hoped that with increasing knowledge about remains of as many taxa as possible, a more complete picture of the past cladoceran assemblages can be obtained, together with a more precise assessment of past ecological conditions, such as pH and trophic state.

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Subfossil chydorid taxa and assemblages from lake sediments in Poland and Finland with special reference to climate

Sarmaja-Korjonen K., Szeroczyńska K., Gąsiorowski M.

Studia Quaternaria

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2003

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Vol. 20

25-34

EN

In this study we compared chydorid cladoceran (Chydoridae) taxa and assemblages from sediments of 6 Polish and 6 Finnish lakes and investigated if the difference in climate of these two countries can be detected in the cladoceran data. The data were analysed in terms of 1) average relative proportions of chydorid taxa during the history of each lake and by 2) redundancy analysis (RDA) to explain the present effect of environmental variables (altitude, area, maximum depth, mean annual temperature, mean summer temperature and length of the growing season) on species abundances. The redundancy analysis (RDA) enabled us to distinguih groups of taxa 1) with a high thermal preference 2) associated with small, cold-water lakes and 3) associated with shallow lakes. There are clear differences in the dominant chydorid taxa and in the relative proportions of many other chydorid taxa between the two countries since the end of the last glaciation. Although these differences first of all appear to reflect the climatic difference, the influence of many other environmental factors, controlling the living conditions of particular chydorids have been raised and considered. Further studies with larger data are needed before the role of climate can be reliably separated from other elements of environment.