Observations of the diatoms Sceptronema orientale Takano and Tabularia parva (Kützing) D.M.Williams & Round on the exoskeleton of copepods in the English Channel and coastal Celtic Seas

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.