Sex-specific grazing dynamics of the recently described copepod, Lovenula raynerae, in an ephemeral pond in the Eastern Cape province of South Africa

Abstract

This study investigated the temporal changes in the sex specific ingestion rates of the recently described calanoid copepod, Lovenula raynerae, which numerically and by biomass dominates the plankton community in ephemeral ponds in the Eastern Cape province of South Africa. Ingestion rates of the copepod were investigated on two occasions, one week after emergence and two weeks thereafter, employing the gut fluorescent technique. Results of the study indicate the absence of any diel patterns in feeding for both sexes on both sampling occasions (p > 0.05 in both cases). Moreover, there was no significant differences in gut pigment contents between adult male and females during either of the surveys (p > 0.05). Daily rations of the adult copepods during the two studies were equivalent to <2% (range 0.8 to 1.8%) body carbon per day suggesting that they are consuming alternative carbon sources to meet their daily carbon requirements. The main findings of this study suggest that L. raynerae can be considered as a generalist omnivore.

Keywords: copepod, ephemeral ponds, gut fluorescent technique