Jan Igor Rybak

The responses of littoral invertebrates to eutrophication-linked changes in plant communities

The decay of submerged macrophytes in lakes of high trophic level drastically limits the extent of habitat available to littoral invertebrates. The loss can be partially compensated by growth of filamentous algae. Our results show that macroinvertebrates typically associated with submerged macrophytes as well as planktonic crustaceans and rotifers occurred within algal mats at high densities.Aggregations of filamentous algae are usually short-term, with frequent appearances and disappearances. The rate of colonization of algal mats by invertebrates is rapid. In locations with a high degree of water exchange, animals colonize both living and decomposing algal mats at a similar rate, but in sheltered habitats, decomposing filamentous algae are colonized by a smaller number of animals.Comparison was made between the occurrence of invertebrate macrofauna on Chara spp., Potamogeton perfoliatus, P. lucens and Myriophyllum spicatum in several lakes. Although these macrophytes differ visibly in morphology and phenology, the number and composition of macroinvertebrates during summer was associated more closely with trophic state of a lake than with plant species.

Biotic interactions of the zooplankton community of a shallow, humic lake

The objective of this paper was to recognize the predator-prey relations and competitive interactions in the zooplankton community of a shallow, humic Lake Flosek (Great Masurian Lake District). The year to year changes in the seasonal pattern and sequence of peak abundance of herbivore and predatory Crustacea and Rotifera were observed. zooplankton in this lake showed also a distinct vertical distribution and more or less visible diel vertical migrations as well as the horizontal migration of Crustacea species between pelagial and near-shore zones of lake in summer period. The changes of demographic events like the decrease of mean body size of adults as well as decrease of fecundity along the inshore-offshore transect were also observed. This distinct habitat partition between crustaceans and rotifers can reflect a combined effect of food scarcity and predator pressure.

Introduction to Copepoda

The global diversity of free-living (non-parasitic) copepods is estimated to be around 2814 freshwater species out of around 11,500 morphospecies mostly found in marine environments (Humes 1994; Balian et al. 2008). These authors estimated the presence of 1204 species in the Palearctic area. The European part consists of around 25 % of the Palearctic area and the 158 copepod species described here in our key make up slightly less than 15 % of the total number of species estimated for the Palearctic, including both surface and subsurface species.

The swimming behavior of planktonic crustaceans colonizing algal mats

Laboratory experiments showed that both cladocerans and copepods are able to overcome a filamentous algae barrier, and are able to move within algal mats. This suggests that the crustaceans noted in large numbers in accumulations of algae actively colonize these mats and live inside of them.

Ecological Features, Coefficients, and Equations

Various ecological projects have required basic ecological features, coefficients, or equations describing Cladocera and Copepoda; some of them are presented in Table 2.1.

Characteristics of Orders, Families, and Genera with a List of European Species

This section covers description of Cladocera taxonomic ranks and provides a list of genera and species reported from Europe.

Key to Copepoda

This chapter covers the dichotomous-pictorial key for genera and species identification of planktonic Copepoda (Calanoida, Cyclopoida) reported from Europe. Here, we provide separate male and female keys to the calanoid copepods, for both, the genera and species levels. We attempted to use autapomorphic characters and, whenever possible, almost a single character to distinguish between similar species, in an easy pictorial way, avoiding long verbal descriptions equipped with scientific jargon. Keys to families, genera and species are arranged into plates with an easy-to-use pictorial guide.

Key to Cladocera

This chapter covers the dichotomous-pictorial key for genera and species identification of planktonic Cladocera reported from Europe. We attempted to use autapomorphic characters and, whenever possible, almost a single character to distinguish between similar species, in an easy pictorial way, avoiding long verbal descriptions equipped with scientific jargon. Keys to families, genera and species are arranged into plates with an easy-to-use pictorial guide.

Characteristics of Orders and Families with a List of European Genera and Species

The order Calanoida is composed of species with 16–26-segmented antennules and biramous antennae. The leg P5 is modified into a copulatory organ in males. The abdomen is narrow and a heart is present. The order is composed of 42 families with 289 genera of which only four families are present exclusively in freshwaters and another five are freshwater and marine. Only four families and 22 genera are reported from European freshwaters (Dussart and Defaye 2001, 2002; Boxshall and Halsey 2004). The order Calanoida is a rather homogeneous group, adapted primarily to planktonic life (Park 1986). Andronov (1974) divided the order of Calanoida into nine superfamilies (based on the structure of the male A1 and legs P1–P6 in both sexes) and later Park (1986) divided them into 11 superfamilies, which was generally recognized by Boxshall and Halsey (2004). The first parsimony-based phylogeny using morphological data for the calanoid copepods was provided by Bradford-Grieve et al. (2010). Soon after, Blanco-Bercial et al. (2011) elaborated the molecular-based phylogenetic analysis. Both analyses (morphological and molecular) recover several monophyletic lineages within the Calanoida that largely conform to the superfamilies recognized in intuitive classification by Andronov (1974), Park (1986), and Boxshall and Halsey (2004).