TY - JOUR
T1 - Density and depth variations of Daphnia multilocus genotypes during a summer period in Lake Maarsseveen
AU - Ringelberg, J.
AU - van Gool, E.
AU - Brehm, Michaela
N1 - Reporting year: 2004
Metis note: 3488; CL; AFW ; AqE file:///L:/Endnotedatabases/NIOOPUB/pdfs/Pdfs2004/Ringelberg_ea_3488.pdf
PY - 2004
Y1 - 2004
N2 - The genotype composition of a Daphnia population complex during a summer period in Lake Maarsseveen (The Netherlands) was determined by allozyme analysis. The depth distribution, diel vertical migration and several parameters of the total population were measured. Young-of-the-year (0+) perch (Perca fluviatilis) were caught and species and allozyme types of Daphnia in the perch gut were also analysed. During May 1997, the densities of D. hyalina, D. galeata, the back-cross D. g x h – hyalina and the multilocus allozyme genotypes of the hybrid D. g x h decreased, except one multilocus genotype (MMMF). Total population size decreased and the ratio of females with eggs to those without eggs decreased as well. Food limitation during this clear-water phase in the lake is considered responsible. All genotypes, except MMMF, gradually descended in the water column. This drift is thought to be a reaction to the abundantly present 0+ perch or to the kairomones of this fish, although predation on the daphnids was still absent. In June, diel vertical migration started, except again part of the MMMF subpopulation. The other part migrated over a short distance compared with the other taxa and allozyme types. Within two weeks, the upper 5 m of the epilimnion was devoid of Daphnia, and guts of perch were predominantly filled with MMMF. The daphnids in the gut and the lake did not differ in allozyme type composition. By the end of July, population density had increased again. The size and composition of the Daphnia population complex continuously changed during the study period, as did the depth distribution of the components. Different genotypes within the population complex seem to have developed different strategies to cope with starvation and predation and the state at a particular moment can be understood only if past and present factors are considered. [KEYWORDS: Allozymes ; Daphnia hybrids ; Diel vertical migration ; Fish gut contents ; Fish predation ; Food limitation ; Population dynamics ; Vertical distribution]
AB - The genotype composition of a Daphnia population complex during a summer period in Lake Maarsseveen (The Netherlands) was determined by allozyme analysis. The depth distribution, diel vertical migration and several parameters of the total population were measured. Young-of-the-year (0+) perch (Perca fluviatilis) were caught and species and allozyme types of Daphnia in the perch gut were also analysed. During May 1997, the densities of D. hyalina, D. galeata, the back-cross D. g x h – hyalina and the multilocus allozyme genotypes of the hybrid D. g x h decreased, except one multilocus genotype (MMMF). Total population size decreased and the ratio of females with eggs to those without eggs decreased as well. Food limitation during this clear-water phase in the lake is considered responsible. All genotypes, except MMMF, gradually descended in the water column. This drift is thought to be a reaction to the abundantly present 0+ perch or to the kairomones of this fish, although predation on the daphnids was still absent. In June, diel vertical migration started, except again part of the MMMF subpopulation. The other part migrated over a short distance compared with the other taxa and allozyme types. Within two weeks, the upper 5 m of the epilimnion was devoid of Daphnia, and guts of perch were predominantly filled with MMMF. The daphnids in the gut and the lake did not differ in allozyme type composition. By the end of July, population density had increased again. The size and composition of the Daphnia population complex continuously changed during the study period, as did the depth distribution of the components. Different genotypes within the population complex seem to have developed different strategies to cope with starvation and predation and the state at a particular moment can be understood only if past and present factors are considered. [KEYWORDS: Allozymes ; Daphnia hybrids ; Diel vertical migration ; Fish gut contents ; Fish predation ; Food limitation ; Population dynamics ; Vertical distribution]
U2 - 10.1007/s10452-004-5667-5
DO - 10.1007/s10452-004-5667-5
M3 - Article
VL - 38
SP - 525
EP - 535
JO - Aquatic Ecology
JF - Aquatic Ecology
SN - 1386-2588
IS - 4
ER -