Elemental composition of two coexisting Daphnia species during the seasonal course of population development in Lake Constance
- 1 October 1990
- journal article
- Published by Springer Science and Business Media LLC in Oecologia
- Vol. 84 (3), 340-350
- https://doi.org/10.1007/bf00329757
Abstract
In 1986 and 1987 the seasonal course of population density, life history traits and biomass composition (CHN-elemental and ash) of two coexisting Daphnia species from L. Constance (Überlinger See) were studied. The two daphnids are morphologically similar, but demonstrate different seasonal variation of behaviour (i.e. diurnal vertical migration). With the exception of nitrogen content, the mean biomass composition of adults and that of eggs were significantly different: the dry biomass of eggs (adults) contained on average 55.6 (46.1) % C, 7.9 (6.5) % H, 9.7 (9.7) % N, and 10.0 (23.8) % ash. These values were similar to those of other daphnids; it may be concluded that the average daphnid composition is not species specific, but is determined mainly by the position in the life cycle and by the nutritional state of the animal. A distinct seasonal variation in the elemental composition of the biomass of adult daphnids was observed. It related significantly to the concentration of food, as indicated by the epilimnetic chlorophyll-a concentrations and by Secchi depth. From the amplitude of seasonal variation of elemental composition and from the shape of relationships between the elemental composition of daphnids and their food, it can be concluded that in summer the non-migrating D. galeata lives under stronger food limitation than the migrating H. hyalina. In spring, there were no differences in the biomass composition of either species. In summer, the adult fcmales of D. galeata contained significantly less carbon, and hydrogen than those of D. hyalina. In most parameters of biomass (i.e. biomass composition of adults) and of life history (i.e. clutch size, mean adult weight), D. galeata displayed higher coefficients of variation. A tendency in D. galeata to have peaks of population development carlier in the season and in D. hyalina to have them towards autumn was observed. These contrasting responses of the populations development, the seasonal variability of the biomass composition seem to support the view of Geller (1986) who called D. galeata and D. hyalina “exploitative” and “conservative” strategists respectively.Keywords
This publication has 39 references indexed in Scilit:
- Composition chimique élémentaire (C, H, N) et équivalent énergie d'Acartia clausi (Crustacea: Copepoda), espèce importante dans la bioénergétique des écosystèmes côtiers de Méditerranée nord-occidentaleMarine Biology, 1987
- Resource dynamics and seasonal changes in competitive interactions among three cladoceran speciesJournal of Plankton Research, 1987
- Seasonal variability in the relationship between body length and individual dry weight as related to food abundance and clutch size in two coexisting Daphnia speciesJournal of Plankton Research, 1985
- Seasonal variations in length, dry weight, carbon and nitrogen of Calanus helgolandicus from the Celtic SeaMarine Ecology Progress Series, 1984
- Starvation and the size structure of zooplankton communities*Freshwater Biology, 1976
- The relation of energy and organic carbon in aquatic invertebrates1Limnology and Oceanography, 1976
- The chemical composition and energy contents of copepods and cladocerans in relation to their sizeFreshwater Biology, 1976
- Egg‐Size Cycle of a CladoceranEcology, 1974
- Seasonal Calorific Values of Freshwater Zooplankton, as Determined with a Phillipson Bomb Calorimeter Modified for Small SamplesJournal of the Fisheries Research Board of Canada, 1971
- Calorific Values of Some Invertebrates in Lake Mendota, WisconsinJournal of the Fisheries Research Board of Canada, 1968