A massive bloom of Karenia species (Dinophyceae) off the Kamchatka coast, Russia, in the fall of 2020.

In the fall of 2020, a long-lasting and massive harmful algal bloom (HAB) with extensive fields of yellow sea foam was observed in relatively cold waters (7-13 °C) off the coasts of the Kamchatka Peninsula, Russia. According to the estimates based on bio-optical parameters in satellite imagery, the Kamchatka bloom 2020 lasted for two months and covered a vast area of more than 300 × 100 km. An abundance of dead fish and invertebrates, including sea urchins, sea anemones, chitons, cephalopods, bivalves were found on shore during the bloom.

Germ plasm-related structures in marine medaka gametogenesis; novel sites of Vasa localization and the unique mechanism of germ plasm granule arising.

Germ plasm, a cytoplasmic factor of germline cell differentiation, is suggested to be a perspective tool for in vitro meiotic differentiation. To discriminate between the: (1) germ plasm-related structures (GPRS) involved in meiosis triggering; and (2) GPRS involved in the germ plasm storage phase, we investigated gametogenesis in the marine medaka Oryzias melastigma. The GPRS of the mitosis-to-meiosis period are similar in males and females.

Development of the tentacular apparatus in sipunculans (Sipuncula): I. Thysanocardia nigra (Ikeda, 1904) and Themiste pyroides (Chamberlin, 1920).

The development and arrangement of the tentacular apparatus of Thysanocardia nigra (Ikeda, 1904) and Themiste pyroides (Chamberlin, 1920) are described and illustrated using scanning electron microscopy. In T. nigra, the tentacular apparatus is composed of two crowns: the nuchal arc enclosing the nuchal organ and a crown of numerous oral tentacles arranged in U-shaped festoons.

Taxonomic study of the kinorhyncha in Japan. III. Echinoderes sensibilis n. sp. (Kinorhyncha: Cyclorhagida) from Tanabe Bay.

A new species of echinoderid kinorhynch, Echinoderes sensibilis, is described and illustrated using light and electron microscopy. The specimens were collected from masses of the red algae Corallina pilulifera growing in intertidal pools in Tanabe Bay, Honshu Island, Japan. Diagnostic characters of E.