Species composition and morphology of dinoflagellates (Dinophyta) of epiphytic assemblages of Peter the Great Bay in the Sea of Japan

Abstract

The species composition of dinoflagellates in epiphytic assemblages at 0.5–3 m depth in Sobol Bight (Peter the Great Bay in the Sea of Japan) was examined in August–October 2006. A total of 29 dinoflagellate species were found. Planktonic species contributed 54% and benthic and benthic-planktonic species together contributed 36% to the total number of dinoflagellate species. The latter group was represented by 13 species of eight genera, including five potentially toxic species. The occurrences of Cabra matta Murray et Patterson, Ostreopsis cf. siamensis Schmidt, O. cf. ovata Fukuyo, and Prorocentrum fukuyoi Murray et Nagahama are recorded for the seas of Russia for the first time. Amphidinium carterae Hulburt is the first record for the Far Eastern seas and Pseudothecadinium campbellii Hoppenrath et Selina for the Sea of Japan. Morphological descriptions of dinoflagellates that are new records for the study region or potentially toxic species are given. One to ten species of benthic and benthic-planktonic dinoflagellates per macrophyte were found. In all, 13 species of red algae, 9 brown algae, 3 green algae, and 1 species of seagrass were examined. O. cf. ovata, O. cf. siamensis, and P. fukuyoi were the most frequent and abundant.