Differences in rotifer communities in two freshwater bodies of different trophic degree (Lake Ohrid and Lake Dojran,Macedonia) |
| |
Authors: | Orhideja Tasevska Christian D Jersabek Goce Kostoski Dafina Gušeska |
| |
Institution: | 1.Department of Zooplankton,Hydrobiological Institute,Ohrid,Macedonia;2.Dept. Organismal Biology,University of Salzburg,Salzburg,Austria |
| |
Abstract: | We investigated monogonont rotifers in two natural Macedonian lakes that greatly differ in age, size and trophic state: Lake
Ohrid and Lake Dojran. A main characteristic of Lake Ohrid is the scarcity of nutrients and consequently a low level of primary
production. Lake Dojran represents a typical eutrophic lake. Results clearly indicate that species numbers are negatively
correlated with trophic degree. Qualitative analyses of rotifer compositions in Lakes Ohrid and Dojran showed the presence
of 70 and 55 taxa, respectively. Rotifer assemblages differed in their community structure, population densities, and the
occurrence pattern of dominant species. The density of rotifers increased with increasing nutrient concentration, varying
from min. 0.67 ind. L−1 in June, 2006 to max. 8.2 ind. L−1 in July, 2004 in Lake Ohrid, whereas min. 28.8 ind. L−1 (in December, 2005) and max. 442.5 ind. L−1 (in September, 2005) were recorded in Lake Dojran. Gastropus stylifer and Keratella cochlearis were the most abundant species
in the pelagic zone of Lake Ohrid, averaging monthly densities of 1.2 ind. L−1 and 0.6 ind. L−1, respectively, thereby contributing 29% and 15% to rotifer abundance. In contrast, Lake Dojran rotifers were dominated by
Brachionus spp. Brachionus diversicornis and Brachionus calyciflorus f. amphiceros were most abundant, comprising 40% and 25% of the total rotifer density. These results corroborate our idea, that the trophic
state is an important factor in determining the composition of rotifer communities. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|