Egg production rate and hatching success in relation to feeding selectivity of the planktonic copepod Paracalanus parvus s.l. at a fixed station, southeastern coast of Korea

Abstract

Egg production rate and feeding selectivity of the copepod Paracalanus parvus s.l. were measured monthly at a fixed station near Tong-yeong, southeastern coast of Korea for one year, from January to December 2012. The adult female copepods were incubated at the surface water for 24 hr and their egg production rate and hatching success were measured. At the same time, feeding selectivity of the copepods on phytoplankton and protozoan was evaluated by the removal method. For feeding experiment, phytoplankton was divided into three size groups (i.e. >20&micro m, <3&micro m and 3-20&micro m) and their biomass was measured as chlorophyll-a concentration. Protozoan diets were categorized into three taxonomic groups including dinoflagellate, ciliate and flagellate and each group was divided into two size group (i.e. >20&micro m, <20&micro m). Water temperature, salinity and chlorophyll-a concentration were measured monthly as environmental factors. We discussed the relative contribution of phytoplankton and protozoan diets to the variation of egg production rate and hatching success of the copepods in the coastal waters. were incubated at the surface water for 24 hr and their egg production rate and hatching success were measured. At the same time, feeding selectivity of the copepods on phytoplankton and protozoan was evaluated by the removal method. For feeding experiment, phytoplankton was divided into three size groups (i.e. >20&micro m, <3&micro m and 3-20&micro m) and their biomass was measured as chlorophyll-a concentration. Protozoan diets were categorized into three taxonomic groups including dinoflagellate, ciliate and flagellate and each group was divided into two size group (i.e. >20&micro m, <20&micro m). Water temperature, salinity and chlorophyll-a concentration were measured monthly as environmental factors. We discussed the relative contribution of phytoplankton and protozoan diets to the variation of egg production rate and hatching success of the copepods in the coastal waters.