MATURATION OF FAR EASTERN FLOUNDERS (PLEURONECTIFORMES)
Leading scientist, Dr. of Science (Biology), Kamchatka Research Institute of Fisheries and Oceanography
FLOUNDERS, FAR EASTERN SEAS, MATURATION PROCESS, MATURATION RATE, GEOGRAPHICAL VARIABILITY
The article provides characterization of the process of maturation for almost 40 flounder species, inhabiting the seas of the North Pacific. Body length and age at maturation are demonstrated. Comparative analysis to reveal specifics of maturation by flounder species is made. Geographical trends of maturation are revealed for majority of widespread flounder species in the analyzed group. Dependences between geographical variability of maturation, zoogeographical characteristics and biotops are studied.
NEW DATA ABOUT WALLEYE POLLOCK (THERAGRA CHALCOGRAMMA) INTENSIVE SPAWNING PERIOD IN THE WESTERN KAMCHATKA WATERS
Head of dep., Ph. D. (Biology), Kamchatka Research Institute of Fisheries and Oceanography
WALLEYE POLLOCK, WESTERNKAMCHATKA, GONAD STAGE MATURITY, INTENSIVE SPAWNING
This article based on the data, conducted in January–June 1999–2015 on the commercial trawl and Danish seine vessels couth walleye pollock in the Western Kamchatka waters. By prespawning, spawning and spent fishes ratio was specified intensive spawning time. It lasts during 1.5 month from the beginning of April till the middle of May.
SPECIES COMPOSITION AND DISTRIBUTION OF SEA CUCUMBERS (ECHINODERMATA: HOLOTHUROIDEA) ON THE SHELF OF THE WEST KAMCHATKA (THE NORTHEAST PART OF THE OKHOTSK SEA)
V.G. Stepanov*, E.A. Arkhipova, E.G. Panina*
* Researcher, Ph. D. (Biology); reseacher, Ph. D. (Biology); Kamchatka Branch of PIG FEB RAS
Leading scientist, Ph. D. (Biology), Kamchatka Research Institute of Fisheries and Oceanography
ECHINODERMATA, HOLOTHURIAN, SEA CUCUMBER, HOLOTHUROIDEA, SYNONYMY, SPECIES COMPOSITION, DISTRIBUTION, THE OKHOTSK SEA
The article provides results of figuring out the species composition of Echinodermata on the shelf of West Kamchatka (the northeast part of the Okhotsk Sea) on collections obtained by KamchatNIRO and TINROCenter (1992–2015) and materials of Zoological Institute of RAS and P.P. Shirshov Institute of Oceanology of RAS. The work has revealed 23 species of sea cucumbers. Modern and synonymous names and info about distribution are provided for every species. It is first time when the sea cucumbers Cucumaria okhotensis (57°28′–57°32′ N, 156°23′–156°35′ E) of genus Zygothuria, Pseudocnus pusillus(53°18′–58°00′6 N, 154°15′8–155°36′8 E), Psolus chitonoides (57°52′4–58°02′ N, 155°39′5–155°43′ E), Myriotrochus rinkii (55°14′9 N, 155°17′8 E) are found on the shelf of West Kamchatka (the northeast part of the Okhotsk Sea); Zygothuria sp. is found first time in silty-sand ground in the depth 565 m (57°13′1 N, 154°29′8 E).
DIFFERENTIATION OF TROPHIC NICHES AMONG NOSED CHARR (SALVELINUS SCHMIDTI) IN LAKE KRONOTSKOYE (KAMCHATKA) ACCORDING PARASITOLOGICAL DATA
O.Yu. Busarova, G.N. Markevich*, R. Knudsen**
Associate prof., The Far Eastern State Technical Fisheries University
* Researcher, FSBI “Kronotsky Reserve”
** Professor, University of Tromsø
NOSE CHARR SALVELINUS SCHMIDTI, CHARRS GENUS OF SALVELINUS, LITORAL, TROPHIC GROUPS OF FISHES, PARASITE-INDICATORS, ECOLOGY OF FISH, FEED OF FISH, LAKE KRONOTSKOYE, KAMCHATKA
Two ecological groups of benthivorous Nosed charrs are demonstrated for the Lake Kronotskoye on the content of stomachs and fauna of parasites. One group feeds on gammarids only and typically bears plenty of gammaridtransmitted parasites (Cystidicola farionis, Cyathocephalus truncatus, Crepidostomum metoecus). The other group feeds on different sedentary invertebrates and insect larvae, and has much more diverse fauna of parasites, where Phyllodistomum umblaeand Proteocephalus longicollisare the most frequent, but the abundance of all components of the fauna is low. The conditional biomass of parasites in the first group of Nosed charrs is higher comparing to the second group.