How do harpacticoid grazing rates differ over a tidal cycle? Field verification using chlorophyll-pigment analyses
Four species of meiobenthic copepods were examined for diatom feeding. Microscopic analysis of gut-pellet contents from field-collected individuals indicated frequent ingestion of diatoms by 3 harpacticoids (Scottolana canadensis, Microarthridion littorale, Cletocamptus deitersi) while occasional diatom ingestion occurred Paronychocamptus huntsmani. Frustules were usually empty and broken, indicating that contents were digested. Laboratory experiments using 14C-labeling showed assimilation of diatoms by the 3 species examined. Field grazing rate studies were conducted over different portions of a tidal cycle using fluorescent chlorophyll-pigment analysis of gut-contents. Highest diatom consumption (p<0.05) occurred just after the mudflat became exposed (i.e. Early Low Water level, ELW) for S. canadensis, while consumption at Late Low Water (LLW, i.e. after mudflat is exposed for several hours) was reduced. M. littorale showed a somewhat similar pattern in that highest consumption rates (p<0.05) also occurred during ELW. However, during High Water (HW) and LLW a similar (but reduced) feeding rate was measured. P. hunstmani appeared to only ingest diatoms (i.e. chl-pigments) during HW. Relationships of feeding processes over a tidal cycle are discussed with regard to distributional patterns in intertidal and subtidal habitats.
Published in Marine Ecology Progress Series, Volume 45, 1988, pages 263-270.
Decho, A. W. (1988). How do harpacticoid grazing rates differ over a tidal cycle? Field verification using chlorophyll-pigment analyses. Marine Ecology Progress Series, 45, 263-270.
© Marine Ecology Progress Series, 1988, Inter Research