Feeding selectivity of the harpacticoid copepod Canuella perplexa in benthic muddy environments demonstrated by HPLC analyses of chlorin and carotenoid pigments

Abstract

The natural diet and the feeding selectivity of the harpacticoid copepod Canuella perplexa T & A Scott, 1893 were studied in submerged muddy sediments of artificial lagoons in Arcachon Bay (SW France) This study focused on the role of phototrophic microorganis~ns as food sources. Therefore, chlorln and carotenoid pigments in copepods were compared with those present In the top 3 cm of the sediment. High performance liquid chromatography with o n -l ~n e measurement of absorption spectra was used for separation, identification, and quantification of pigments. Diatoms, purple phototrophic bacteria, cyanobacteria, and green microalgae contributed to the benthic phototrophic community. C perplexa ingested diatoms and infrequently cyanobacteria and/or green microalgae in preference to purple phototrophic bacteria. Ingested chlorophyll was converted into phaeophytln and phaeophorblde-like compounds Moreover the copepod synthesized astaxanthin and a related isomer most likely from lngested p-carotene.