Age and growth of threaded sculpin <Emphasis Type="Italic">Gymnocanthus pistilliger</Emphasis> (Cottidae) in the southern Primorye (Sea of Japan)

The features are discussed of the growth of threaded sculpin Gymnocanthus pistilliger in the southern part of its range, in the Sea of Japan. Several methods were tested to determine the age of this species. The improved approach is suggested for determinating the age of threaded sculpin by annual increments on sagitta using thin cross-sections, characteristics of optical density in different zones of otolith growth, and their positions relative to otolith center. It was demonstrated that the growth rate of threaded sculpin in the waters of southern Primorye was significantly higher than in the northern part of its range: the males reached a length of about 20 cm and the females about 22 cm at the age 5+. The maximum length of individuals, 26 cm in the males and 31 cm in the females, significantly exceed those known from literature. The longevity of threaded sculpin calculated for maximum size is 12–13 yr for the waters of Primorye.     

Effect of serotoninergic substances on escape behavior in acute stress situations

The data are provided on the effect of some serotoninergic substances on the avoidance behavior under acute stress. 5-Hydroxytryptophan, zimelidine (low doses), pyrenepyron, ciproheptadine, trazodon (high doses), produced a noticeable positive action on the behavior pattern under study. Quipazin and zimelidine (high doses) provoked an increase in the number of affective manifestations and a rise of the latent avoidance time. Regardless of an appreciable fall in the number of affective manifestations, the powerful sedative effect of m-chlorphenylpiperazine led to an increase in the latent response periods. It was shown that substances that produced a direct or mediated activation effect on the serotoninergic system had an appreciable favourable influence on the avoidance behavior, which was a consequence of a decrease in the animals' emotional excitement. Combination of serotonin-blocking properties (action on S2-autoreceptors) and dopaminergic properties brought about optimal results, provided that pyrenepyron was applied.     

First description of larvae of Radulinopsis derzhavini Soldatov et Lindberg, 1930 (Scorpaeniformes: Psychrolutidae) with remarks on melanin colouration and relationships with related species

The Derzhavin's sculpin (Radulinopsis derzhavini Soldatov et Lindberg, 1930) is a psychrolutids species that leads a cryptic life in coastal waters of the Japan Sea and the southern Okhotsk Sea. To date, larvae of this species have remained unknown; therefore, their biology is poorly understood. In the present study, the early developmental stages of R. derzhavini are described for the first time. In Peter the Great Bay, Japan Sea, this species is characterized by a spring spawning season (May) and a short pelagic period of larval development, usually from mid-May to the last 10 days of June. Species identification of the described larvae was confirmed by incubation, rearing of larvae in captivity, and genotyping of a fragment of the mitochondrial cytochrome c oxidase I (COI) gene. In addition, the development of pigmentation in larvae of this and related species was compared. Morphological analysis of both adults and larvae, together with complementary molecular genetics, confirms the previously obtained conclusions that the species of the genera Radulinopsis, Radulinus, Asemichthys, and Astrocottus form a natural group with monophyly by all types of data.     

A Description of Chirolophis japonicus and Ch. saitone (Stichaeidae) Pelagic Larvae from Peter the Great Bay,Sea of Japan

Journal of Ichthyology - The larval development of Chirolophis japonicus and Ch. saitone from the yolk-sac stage to the settlement on the bottom is described from waters of Peter the Great Bay, Sea...     

Species Composition and Structure of Ichthyoplankton of the Northern Part of the Sea of Japan in Summer of 2017

Journal of Ichthyology - The ichthyoplankton of the upper epipelagic zone (0–50 m) was studied in the northern part of the Sea of ​​Japan in July–August 2017. Eggs of seven...     

Identification of Larvae of Stichaeus fuscus Miki et Maruyama, 1986 (Perciformes: Stichaeidae) and Their Distribution in the Far Eastern Seas

Russian Journal of Marine Biology - Larvae of Stichaeus fuscus from the Sea of Japan and the Sea of Okhotsk have been identified and their diagnostic traits described. Larvae of this species were...     

The Use of the Mortality Rate of Marine Fish Prelarvae for the Estimation of Zinc and Lead Toxicity

The effect of zinc on the prelarvae of the Japanese anchovy Engraulis japonicus and on the sand flounder Limanda punctatissima punctatissima and of lead on the prelarvae of the Japanese anchovy was investigated. The median lethal concentrations and maximum ineffective concentrations for a 96-h exposure were calculated. The maximum ineffective concentrations of metals did not exceed their background levels in Peter the Great Bay (Sea of Japan) but were markedly lower than the maximum permissible concentrations (MPC) set for waters of the seas of the Russian Federation. The prelarvae of the Japanese anchovy and the sand flounder can be useful for evaluation and comparison of the toxicity of pollutants and for the estimation of regional MPC levels for pollutants of marine waters.     

First Record of Ulca bolini (Pisces: Hemitripteridae) in the Southeastern Part of the Sea of Okhotsk

This paper presents data on the first record of Ulca bolini. The fish was caught at a depth of 280–300 m in the Sea of Okhotsk off the Kuril Islands (Prostor Bay, Iturup Island). It was 60 cm in fork length (FL) and 7 kg in weight.