Search results for "Naididae"
showing 5 items of 5 documents
Meiofauna ratios as environmental indicators in the profundal depths of large lakes.
1995
Two sets of samples from Lake Paijanne and one from Lake Ladoga were used to examine the relations between the meiofauna and environmental variables. The most obvious indicators of an unpolluted environment were, in order of importance, the true meiofauna/total meiofauna ratio, the proportion of Aeolosomatidae, the proportion of Harpacticoida (excluding C. staphylinus), the meiofauna/macrofauna biomass ratio, the proportion of Naididae and the A. crassa + P. schmeili/true meiofauna ratio. Conversely, the clearest indicators of a polluted environment were the proportion of resting stages of Cyclopinae, the Nematoda/non-resting Copepoda ratio, and the proportions of Tubificidae, Oligochaeta, …
Meiofauna of the profundal zone of the northern part of Lake Ladoga as an indicator of pollution
1996
Benthic meiofauna was sampled at 19 stations, mainly in the northern part of Lake Ladoga, from depths between 13 and 199 m and from types of environment ranging from sheltered areas near pollution sources to less polluted open areas. About 80 taxa were identified, of these 70 to the species level. The greatest numbers of species were oligochaetes (24 species) and harpacticoids (8 species). Certain quantitative ratios of meiofauna were shown to be correlated with environmental data. The species of the oligochaete families Lumbriculidae and Aeolosomatidae and the harpacticoids as a collective group, excluding Canthocamptus staphylinus, were most clearly confined to the less eutrophied environ…
Meiobenthic naidid and aeolosomatid oligochaetes from the profundal zone, and relations of species to eutrophication
1989
Oligochaetes were sampled using meiobenthos methods from depths of between 20 and 94 m in Lake Paijanne in 1986. Individuals belonging to several species of the Naididae and Aeolosomatidae, which are generally considered to include mainly littoral or lotic species, were found more or less regularly at these profundal depths. The naidid species Chaetogaster langi and Arnphichaeta leydigii were more abundant in the deepest areas than at 20 m. Species also appeared to react differently to water quality. The naidid species Chaetogaster langi and the aeolosomatid species Aeolosoma quaternarium, A. hernprichi and Rheomorpha neiswestnovae were most abundant on average at oligotrophic, unpolluted s…
The occurrence of oligochaetes in lake chains receiving pulp mill waste and their relation to eutrophication on the trophic scale
1987
Earlier conceptions of oligochaetes as indicators of trophy were somewhat enlarged to include more littoral, meiofaunal and naidid species. The amplitudes of different species on the oligotrophy-eutrophy axis seem to be generally large. Certain species which probably originally occur mainly in very humic environments seem also to be able to endure very strong organic loading caused by pulp mills. Species of this kind seem to be Dero digitata, Specaria josinae, Slavina appendiculata and Aulodrilus pluriseta. Chaetogaster langi and Arcteonais lomondi are also species which live in areas receiving pulp mill wastes. A. lomondi and D. digitata seem to be species living in greater depths than the…
Lacustrine, profundal meiobenthic oligochaetes as indicators of trophy and organic loading
1994
Meiobenthic and macrobenthic oligochaetes were collected from two depths in Lake Pajanne and examined together with environmental data in which two environmental gradients can be seen. Numbers of Piguetiella blanci, Aeolosoma quaternarium and Aeolosoma hemprichi were positively correlated with oxygen saturation and negatively correlated with total phosphorus and COD suggesting that these species are indicators of oligotrophic conditions. Numbers of Amphichaeta leydigii, Specaria josinae and Vejdovskyella comata were positively correlated with total phosphorus which implies that these species prefer eutrophic conditions. The last three species and Dero digitata showed positive correlations w…