Effects of spatial distribution of light on prey ingestion of Atlantic halibut larvae

The hypothesis that light distribution affects prey distribution and in turn influences prey ingestion was tested on Atlantic halibut larvae Hippoglossus hippoglossus. Low intensity concentrated light produced swarms of Artemia sp., but did not affect the distribution of Brachionus plicatilis. Low intensity diffused light, however, did not create swarms with either prey. As a consequence, halibut larvae ingested more Brachionus than Artemia in concentrated light, but not in diffused light. Due to differences in dry weight between Artemia and Brachionus, ingested biomass values were indistinguishable under the two experimental regimes.The term‘ population ingestion value’ is introduced as an expression for the ingestive capability of the population as a whole.