Regeneration from hyaline cysts of Cochlodinium polykrikoides (Gymnodiniales, Dinophyceae), a red tide organism along the Korean coast

Abstract

Recently, the Korean coast has suffered from recurrent red tides caused by the dinoflagellate, Cochlodinium polykrikoides, which has caused tremendous damage to aquaculture. In this study, the hyaline cysts produced by C. polykrikoides are described. These cysts can survive up to 6 months when preserved at 4°C in the dark. Cochlodinium polykrikoides motile cells regenerated successfully when transferred to 20°C, a photon flux density of 40 μmol photons m−2 s−1, and 14 : 10 h light-dark photoperiod. The formation of hyaline cysts in the life cycle of C. polykrikoides may act as an overwintering survival strategy, the cysts being able to initiate harmful blooms when favourable conditions return.