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.

Symmetry of priapulids (Priapulida). 2. Symmetry of larvae.

Larvae of priapulids are characterized by radial symmetry evident from both external and internal characters of the introvert and lorica. The bilaterality appears as a result of a combination of several radial symmetries: pentaradial symmetry of the teeth, octaradial symmetry of the primary scalids, 25-radial symmetry of scalids, biradial symmetry of the neck, and biradial and decaradial symmetry of the trunk. Internal radiality is exhibited by musculature and the circumpharyngeal nerve ring.

Symmetry of priapulids (Priapulida). 1. Symmetry of adults.

Priapulids possess a radial symmetry that is remarkably reflected in both external morphology and internal anatomy. It results in the appearance of 25-radial (a number divisible by five) symmetry summarized as a combination of nonaradial, octaradial, and octaradial (9+8+8) symmetries of scalids. The radial symmetry is a secondary appearance considered as an evolutionary adaptation to a lifestyle within the three-dimensional environment of bottom sediment.

Low birth weight and risk of cardiac arrhythmias in children.

Background: This study aimed to investigate a possible association between low birth weight (LBW) and other perinatal major characteristics and the risk of a child having accessory pathways of conduction tissue and cardiac arrhythmia later in life.

Methods: Thirty-one children aged 1-15 years (12 boys, 19 girls), in whom the persistence of accessory pathways of conduction tissue in the heart and inducible reciprocating supraventricular tachycardia were confirmed by means of programmable transoesophageal pacing, constituted the study group. None of them exhibited signs of either inborn or acquired heart disease causing arrhythmia, and their parents and siblings did not suffer cardiac arrhythmias.

Microscopic anatomy and ultrastructure of the introvert of Priapulus caudatus and P. tuberculatospinosus (Priapulida).

Introverts of Priapulus caudatus and P. tuberculatospinosus bear 25 rows of scalids, as well as 8 spines and scattered papillae in the region the circumoral lip. These, as well as the first ring of pharyngeal teeth in P.

[Alcohol as a pathological factor for patients with acute and chronic viral hepatitis and liver cirrhosis].

The investigations have shown presence of HBsAg in the blood sera of 4% of alcohol abusers and in 17.7% of chronic alcoholics. Among 274 patients with acute viral hepatitis A, more than 50% abuse alcohol.