Acartia clausi (Crustacea, Copepoda, Calanoida, Acartiidae), body length 850 µm, Helgoland 06.2019. 0:44 min. These specimens come from a culture of the Biologische Anstalt Helgoland. They can be found in brackish waters of estuaries and lagoons, e. g. in the Mediterranean. Antennae 1 of the genus with characteristic pattern of setae. Urosome as in many copepods with a fan of plumose setae. Suspension feeders, maxilla 2 forms a feeding basket. Video can be used for teaching.