MEPS 143:77-86 (1996)  -  doi:10.3354/meps143077

Interspecific differences among meiobenthic copepods in the use of microalgal food resources

Pace MC, Carman KR

We examined the potential for interspecific differences among meiobenthic copepods in their exploitation of microalgal food resources in a natural benthic community. The feeding behaviors of Coullana sp., Cletocamptus deitersi, Microarthridion littorale, and Pseudostenhelia wellsi were examined using 14C-radiotracer grazing experiments and gut-pigment analyses. In one grazing experiment, laboratory-cultured microalgae were labeled using NaH14CO3 and injected into intact sediment cores to determine whether copepods were grazing on algae from the water column and/or at the sediment-water interface. In another grazing experiment, NaH14CO3 was injected directly into sediment cores and grazing on 14C-labeled natural algae was measured. Fluorometric analyses of gut-pigments were used to determine the recent feeding histories of copepods. Functional responses of copepod feeding to variation in sedimentary chlorophyll (chl) a concentrations were also used to discern interspecific differences in feeding. Coullana sp. grazed on microalgae from the water-column and at the sediment-water interface. C. deitersi grazed predominantly on microalgae from the sediment-water interface. Grazing on laboratory-cultured algae was minimal in M. littorale and P. wellsi, but grazing experiments with 14C-labeled natural algae and gut-pigment analyses indicated that these copepods grazed on microalgae in the field. However, a positive functional response to chl a concentrations by M. littorale and a lack of a functional response by P. wellsi suggest that these 2 species exploit algal resources differently. Collectively, our observations indicate that each copepod species examined exploits microalgal resources differently.

Meiofauna · Grazing · Microalgae · Harpacticoid copepods · Cletocamptus deitersi · Pseudostenhelia wellsi · Microarthridion littorale · Coullana sp.

Full text in pdf format