A new rotating tumbler apparatus for zooplankton grazing in a laboratory

Abstract

The Low Revolutions per Minute Tumbler (LRPMT) is a new creation which is capable of providing better results in terms of minimum algae sedimentation as compared with other methods in literature. This device maintained the algae sample in suspension during the experiment allowing the grazers to ingest at a maximum rate. Even though the limitation affects the capability of the vessel to work perfectly, we recommended the new device as a suitable method to minimize algae sedimentation during zooplankton feeding experiments. The grazing rates of Daphnia carinata on five algae species (Microcystis flos-aquae, Ankistrodesmus falcatus, Chlorella vulgaris, Scenedesmus obliquus, and Chlamydomonas reinhardtii) were measured in order to understand the interaction between phytoplankton and zooplankton. Although various devices have been used to minimize algal sedimentation during experiments such as: a shaker, plankton wheel, a roller-tube device, and stirrer, reliable equipment is still uncertain and questionable.