Feeding Preferences of Marine Harpacticoid Copepods for Various Species of Bacteria

Abstract

Selective feed~ng experiments were carried out in the laboratory with 4 species of marine harpacticoid copepods (Crustacea: Copepoda) and several different strains of bacteria as food. Of the copepod species tested. Tisbe holothuriae and Paramphiascella vararensis were the most discnminat-ing, whereas no clear preferences could be established for Nitocrella polychaeta and Amphiascoides debilis. The bacteria most attractive to the copepods include Moraxella-like species, Vibrio anguil-larurn (pathogenic for certain fish) and 2 different Flavobacteriurn spp. A Micrococcus sp. was unattractive and possibly actively avoided by Tisbe, and-to a lesser extent-by Pararnph~ascella. The preferred strains of bacteria represent different morphological and physiological groups; all are Gram-negative. The Gram-posltive bacteria tested (cocci) were not significantly preferred by any of the harpacticoids used in the experiments.