Feeding and reproductive performance of the harpacticoid Tisbe carolinensis (Copepoda, Crustacea) in four algal cultures

Abstract

The functional relation between the harpacticoid copepod Tisbe carolinensis and 4 algal strains was examined in the laboratory. T. carolinensis reared either in suspensions of the green alga Chlorella autotrophica (Strain 580) or the 2 blue-green algae Agmenellum quadruplicatum (Strain PR-6 ) and Anabaena sp. (Strain CA) showed marked differential mortalities between sexes, and had fecal production rates of < 0.2 ind-' h-'. T. carolinensisin these algal cultures produced smaller numbers of brood and fewer viable nauplii than those exposed to the pennate diatom Cylindrotheca sp. (Strain N-1) or a mixed diet of all 4 algae. T carolinensis fed actively on S t r a~n N -l and on the mixture, and fecal pellet production rates averaged > 1.2 ind-' h -' Under laboratory conditions (30 %, 24 "C) with Strain N -l , interclutch interval was estimated to be 4 to 4.5 d , of w h~c h 24 to 33 h was required for oviposition and 3 d for embryonic development. Successful f e e d~n g and reproduction on Strain N -l and on algal mixture may be associated with larger particle size and somewhat higher nutritional value (i.e. protein and l~p i d content) of the diatom. This study emphasizes the importance to the copepods of algal type, cell size, and algal protein, carbohydrate, and lipid content, and suggests how these factors may combine to affect T. carolinensispopulation in the field via their effects init~ally on feeding activity and survival rate, and subsequently on e g g production and development

Interacties tussen zeewier en plankton in mesocosm studies; technische rapportage rond toepassing van nieuwe monitoringtechnieken

“…Voor beide groepen vormen eencellige algen, micro-organismen en micro-zoöplankton (m.n. ciliaten) de belangrijkste voedselbronnen (Lee et al, 1985;Rieper, 1982;Roshchin and Chepurnov, 1985;.Lonsdale et al, 1979;Paffenhofer et al, 1982;Williamson and Butler, 1986). Grofweg kan gesteld worden dat calanoide copepoden hun voedsel meer in de waterkolom zoeken, terwijl harptacticoiden meer in de buurt van de bodem of ander substraat foerageren.…”