BIOLOGIYA MORYA, 2026, Vol. 52, No. 1, pp. 5-19

Allelopathy among Bacillariophyta Diatoms

© 2026 Zh. V. Markina

Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russian Federation

Diatoms are the most common unicellular algae in the seas. One of the reasons for their widespread distribution is considered to be high allelopathic activity. This review focuses on intra- and inter-group diatom allelopathy. We discuss different approaches to studying microalgae's allelopathic activity in vitro and explore the mechanisms of allelopathic effects among diatoms, as well as the properties of substances associated with allelopathic activity. Such substances are polyunsaturated aldehydes, which are present in all Bacillariophyta, domoic acid, found in representatives of the genera Pseudonitzschia, Nitzschia and Amphora, and marennine produced by Haslea ostrearia and H. karadagensis.

Key words: diatoms, biotical relationships, allelopathy, polyunsaturated aldehydes, domoic acid, marennine.