The consortium of the epizoic diatom Sceptronema orientale Takano on living individuals of the harpacticoid copepod Euterpina acutifrons Dana was found in summer 2018 in the port of Brest, Celtic Seas, and in several locations of the open English Channel during the summer-autumn transition. Diatoms as epibionts on copepods remained unreported up to date in the region despite the high tradition of plankton observations. Tabularia parva (Kützing) D.M.Williams & Round was attached to the empty carapace of a copepod in the port of Brest. The detailed morphology is illustrated by scanning electron microscopy.