The coccolithophorid Ochrosphaera neapolitana was reported for the first time from samples
obtained during a large-scale mucilage event in the Sea of Marmara in May 2022 in a previous
study. We also found this species in our samples obtained about a year ago (i.e., in June 2021). In
our study, O. neapolitana was further isolated and produced in the laboratory as a monoculture for
further investigations using electron microscopy and molecular methods. Ochrosphaera neapolitana
was identified using a small sub-unit (SSU) rRNA sequence and subsequent phylogenetic analysis.
During the laboratory experiments, O. neapolitana was surprisingly observed to produce conspicuous
levels of mucilage as a skim layer in mono- or multi-species cultures, mainly comprising other
diatom species. This observation could be a significant milestone in understanding the reasons and
mechanisms of mucilage events that occur in the Sea of Marmara.