Influence of spatial heterogeneity on the predation of Mesostoma ehrenbergii on calanoid and cyclopoid copepods. J. Plankton Res. 28(3):267-274. ISI

CAROLINA TROCHINE,; BEATRIZ ESTELA MODENUTTI O BEATRIZ MODENUTTI O B. MODENUTTI; E BALSEIRO,

JOURNAL OF PLANKTON RESEARCH

Oxford University Press

Lugar: Oxford, UK; Año: 2006 vol. 28 p. 267 - 274

0142-7873

Through laboratory experiments, we analysed the influence of spatial heterogeneity on predation byMesostoma ehrenbergii on the calanoid Boeckella gracilis and the cyclopoid Acanthocyclops robustusin four horizontal and two vertical spatial arrangements. This spatial heterogeneity simulated thatof Juncaceae stems, a major macrophyte in the natural environment of these zooplankton. Ourresults indicated that M. ehrenbergii preyed differently on these copepod species. The rate of predationof M. ehrenbergii on A. robustus females reached saturation in all the treatments with and withouthorizontal spatial heterogeneity, but lower predation rates were observed in the medium heterogeneitytreatment. Predation rates of Mesostoma on B. gracilis increased with the increase in preyabundance in the treatment without heterogeneity, while predation rates reached saturation in thetreatments with horizontal spatial heterogeneity. Mesostoma ehrenbergii consumed males andfemales of B. gracilis in each of the arrangements tested. In natural habitats, interaction betweenextent of macrophyte development and intensity of predation by M. ehrenbergii on copepods speciesmay be expected. We suggest that the structural complexity given by macrophytes in Patagonianfishless habitats provide a bottleneck for M. ehrenbergii predation.