Mariia Berdieva, Sofia Pechkovskaya and Olga Matantseva

Institute of Cytology RAS, 194064 Saint Petersburg, Russia

| Submitted April 17, 2020 | Accepted May 11, 2020 |

Summary

Many dinoflagellate species are sensitive to mechanical disturbances, for instance, to mixing, which hampers effective continuous culturing of these organisms. Such sensitivity may be linked to the induction of ecdysis, a process of the cell covering rearrangement, followed by temporary quiescence of the dinoflagellate cells. Ecdysis can be induced in a significant fraction of a dinoflagellate population by unfavorable environmental conditions and is often involved in the formation of their cysts. Previously it was demonstrated that the bacteriostatic antibiotic tetracycline, which is widely used against bacteria in aquaculture, decreased the natural ecdysis rate in the culture of the dinoflagellate Prorocentrum minimum (Pavillard) Schiller, 1933. In this study, we tested the ability of this compound to lower the rate of ecdysis induced by mechanical stimuli. We showed that mechanical disturbances associated with centrifugation, stirring, and shaking equally induced ecdysis in the tetracycline-treated and control cultures. Thus, tetracycline did not make dinoflagellates less susceptible to the mechanical stressors and cannot be used to surpass their sensitivity to mixing during continuous culturing.

Key words:  ecdysis, Prorocentrum minimum, tetracycline