Origin of juvenile chum salmon <Emphasis Type="Italic">Oncorhynchus keta</Emphasis> (Salmonidae) in the Sea of Okhotsk coastal waters off South Sakhalin

Based on the data of the analysis of distribution of juvenile chum salmon Oncorhynchus keta that were marked at salmon hatcheries in the southern part of the Sakhalin Island and Japan it has been established that their stocks in the Sea of Okhotsk coastal waters off South Sakhalin and Japan are of mixed origin. One part of the stock is composed of juveniles from hatcheries located in the southern part of Sakhalin, and the other part is composed of migrants from the waters adjacent to Japan. The first part is formed by juveniles both from hatcheries on the Sea of Okhotsk and Sea of Japan coasts of South Sakhalin. The second part is formed by juveniles reared at hatcheries in all regions of Japan: the Pacific and Sea of Okhotsk coasts of Honshu and Hokkaido, and from the Sea of Okhotsk coast of Hokkaido and Izmena (Nemuro) Strait. In July, in the Sea of Okhotsk coastal waters off South Sakhalin, the length and weight of most juvenile chum salmon of Japanese origin exceed 10 cm and 10 g, and juveniles of Sakhalin origin are always smaller than 10 cm and 10 g, which makes it possible to differentiate juveniles in trawl catches.     

The Karyotype of the flathead sculpin Megalocottus platycephalus taeniopterus (Kner, 1868) (Pisces: Cottidae) from Vostok Bay,Sea of Japan

For the first time, we studied the karyotype of the flathead sculpin Megalocottus platycephalus taeniopterus (Kner, 1868) from Vostok Bay of the Sea of Japan. The karyotype is stable: 2n = 42 (2 metacentric, 2 submeta-subtelocentric, 30 subtelocentric, and 8 acrocentric chromosomes), NF = 44 + 2. The nucleolar organizers (NOs) were identified using Ag banding in two pairs of chromosomes: in the telomeric parts of the short arm of the medium-size subtelocentric chromosome and the long arm of the large acrocentric chromosome. Variations in the number of nucleolar organizer chromosomes and in the number of NO staining blocks were found. Comparison of the karyotypes of M. p. taeniopterus and previously studied M. p. platycephalus (Pallas, 1814) from the northern Sea of Okhotsk revealed their similarity in the number and morphology of chromosomes and the number of chromosome arms and difference between the subspecies in the number and location of NO, which allows their discrimination.     

Specific features of distribution and some features of biology of Korean flounder <Emphasis Type="Italic">Glyptocephalus stelleri</Emphasis> (Pleuronectidae) in waters off Kamchatka in the Sea of Okhotsk

According to materials of 1997–2002, the characteristic of the spatial-bathymetric distribution, size and age composition, size and sex structure, and feeding of the Korean flounder Glyptocephalus stelleri in the summer period in waters off Kamchatka in the Sea of Okhotsk (the site from 51°15′ to 57°20′ N, depths of 10–300 m) is given. It is shown that throughout the observation period, maximum catches of this flatfish were constantly observed at two sites of the western Kamchatka shelf (51°20′–53°00′ N and 55°00′–56°00′ N) in the zone exposed to the effect of anticyclonic gyres in the range of depths 101–200 m at the near-bottom temperature below 2°C. Unlike other habitat areas, off the coast of western Kamchatka, G. stelleri in the summer time is quite frequently found at negative temperature values, which is obviously determined by the specifics of thermal conditions of the eastern part of the Sea of Okhotsk. It was established that, in this species of flatfish, sex dimorphism is distinctly pronounced in sizes—males are considerably smaller than females whose relative number among individuals with a length larger than 50 cm reaches 100%. The main items of feeding of G. stelleri at the western Kamchatka shelf in the summer period are oligochaetes.     

Distribution of the Eelpout Lycodes soldatovi(Pisces: Zoarcidae) over the Continental Slope of the Sea of Okhotsk

The eelpout Lycodes soldatovi was found at depths of 153 to 1005 m in the Sea of Okhotsk; however, it usually inhabits the depth range of 400 to 800. The mean and maximum abundance and the biomass of this species were 198.5 and 1037 individuals per km² and 173.7 and 1275 kg/km², respectively. In view of the data on the distribution of young fish (up to 30 cm in total body length) and the reports on the absence of Lycodes larvae, a hypothesis was developed that this species spawns predominantly in the waters off western Kamchatka and eastern Sakhalin at the depth range of 700 to 900 m. Large individuals (>50 cm) exhibit higher migratory activity and are more tolerant of environmental conditions. That is why they are encountered throughout the distribution area of this species, even in subzero temperature areas. Lycodes soldatovi seems to be a typical inhabitant of the Sea of Okhotsk, except for the waters off the South and Central Kuril Islands and the Pacific waters off the North Kuril Islands.     

Importance of morphological traits and coloration for diagnostics of species of the genus <Emphasis Type="Italic">Mullus</Emphasis> (Mullidae,Perciformes), assessment of the taxonomic status of populations,and revision of ranges

Comparative analysis was performed of morphological characters and coloration elements in goatfish of the genus Mullus from collections of the Zoological Museum (Moscow State University, Russian Academy of Sciences), on the basis of which individuals from Atlantic waters off the coasts of western Africa were identified as M. argentinae. Brief characteristics of all valid species of the genus are presented; the main diagnostic characters include: ratio between the length of the barbels and pectoral fins, number of pyloric caeca, and the presence of a dark spot (or stripe) in the upper part of dorsal fin. The Mediterranean populations of M. surmuletus are separated as a special subspecies M. surmuletus fuscatus, and M. argentinae from eastern Atlantic is described as a new subspecies M. argentinae africanus.     

The description of a new species of Myzopoda (Myzopodidae: Chiroptera) from western Madagascar

A new species of Myzopoda (Myzopodidae), an endemic family to Madagascar that was previously considered to be monospecific, is described. This new species, M. schliemanni, occurs in the dry western forests of the island and is notably different in pelage coloration, external measurements and cranial characters from M. aurita, the previously described species, from the humid eastern forests. Aspects of the biogeography of Myzopoda and its apparent close association with the plant Ravenala madagascariensis (Family Strelitziaceae) are discussed in light of possible speciation mechanisms that gave rise to eastern and western species.     

Distribution,Size, and Some Behavioral Characteristics of the Gray Whales Eschrichtius robustusof the Korean Herd in the Coastal Waters of Northeastern Sakhalin

In August 1997, 56 specimens of Eschrichtius robustuswere recorded in the coastal waters of northeastern Sakhalin (in the area between Odoptu and Chaivo bays). Gray whales are observed there from May till November; they stay within 4–5 km of the coast at a depth of no more than 25 m. The whales keep moving and spend most of their time feeding intensively. The whales occur more often in the area adjacent to Pil'tun Bay than in the rest of the area. A preliminary estimation indicates that the Korean gray whale population includes no more than 100 specimens. In view of this, from now on, the eastern Sakhalin shelf should only be commercially exploited with special care.     

On the biology of Blepsias cirrhosus (Hemitripteridae) from coastal waters of northern Primorye

Data on the distribution, size-age composition, dates, and conditions of spawning, fecundity, and feeding of Blepsias cirrhosus from the coastal waters of northern Primorye are presented. It is demonstrated that individuals in this region reach a length of 19.5 cm, weight of 87.0 g, and age of 6 years. Spawning occurs in the first half of July in coastal reefs at a water temperature of 10–15°C, at depths down to 8 m. The nuptual color of females is described. In connection with a clearly pronounced care for progeny, fecundity is low, 234–404 eggs. B. cirrhosus feeds mainly on nekton and benthic crustaceans.     

The First Finding of the Actinia Synandwakia hozawai in the Sea of Okhotsk

The finding of the actinia Synandwakia hozawai in the coastal waters of northern Sakhalin (Sea of Okhotsk) suggests a wider range of this species, which was previously only known to inhabit the coastal waters of eastern Japan. Data are presented on the morphology of the S. hozawai specimen from the Sea of Okhotsk and the types of its nematocysts.     

Life history and habitat use of Norwegian brown trout (Salmo trutta)

SUMMARY. 1. Brown trout ( Salmo trutta) life history and habitat use were studied in two Norwegian rivers: the Vosso river system, western Norway, and the Søre Osa, eastern Norway.
2. Age-groups were partly segregated in feeding habitats, the youngest fish living mainly in running water and in the littoral zone of lakes, the older fish also exploiting pelagic waters and deeper epibenthic habitats. In a population with free access to and from the sea, some individuals smoltified and became sea-run migrants, performing yearly migrations to the coastal sea, whereas others stayed as freshwater residents throughout their entire life span.
3. Within local populations, females were larger and less variable in size than males. This was partly because females matured at an older age than males, partly because the sexes tended to exploit feeding habitats with different food and growth Conditions. Within age-groups, females were more pelagic and migrated more than males, whereas males were more confined to running water and epibenthic areas than females. In the pelagic zone, males were more abundant in near-surface water, and females more abundant in deeper areas. When exploiting the same feeding areas, the two sexes grew at the same rate. There therefore appears to be a connection between feeding habitat and the reproductive ecology of brown trout.     

Occurrence of skate <Emphasis Type="Italic">Raja pulchra</Emphasis> (Rajidae,Rajiformes) in Russian waters of the Sea of Japan

According to data of long-term observations in Russian waters of the Sea of Japan, it was shown that skate Raja pulchra occurs only off the coasts of western Sakhalin. In all probability, it is a constant inhabitant of these waters during the course of the year; like the overwhelming majority of bottom and near-bottom fish, it performs seasonal bathymetric migrations in autumn, for wintering to the insular slope to a depth of 695 m, and in spring to shallow waters. Maximum length of R. pulchra recorded in catches is 106 cm. The main food items of R. pulchra are decapods and fish. The stock of R. pulchra off the coasts of western Sakhalin is assessed as 520 t.     

Ichthyoplankton of the eastern shelf of Sakhalin Island and its use as an environmental state indicator

Results of studying ichthyoplankton off the eastern coast of Sakhalin Island in July 2002, are presented. The spatial distribution of the eggs and larvae of almost all encountered species confirms the presence of drift along the coast with a gradual drift of passive migrants from the coast of eastern Sakhalin into the open waters. The most diverse and numerous ichthyoplankton was over the shelf zone to the north of 51°00′; the least diverse, from 50°00′ to 51°00′ N. The minimal proportion of the normally developing eggs of the wall-eyed pollack Theragra chalcogramma and the yellow-finned sole Limanda aspera dominant in catches was recorded over the oil-gas deposits located in the coastal zone of the northeastern shelf. The coincidence of stations (83%) with a high proportion of the dead eggs of these fish species can indicate a similar impact on it of environmental conditions formed in deposit areas.     

Distribution and population structure of the smooth‐hound shark,Mustelus mustelus (Linnaeus, 1758), across an oceanic archipelago: Combining several data sources to promote conservation

Sharks play a key role in the structure and functioning of marine ecosystems. More ecological information is essential to implement responsible management and conservation actions on this fauna, particularly at a regional level for threatened species. Mustelus mustelus is widely found in the eastern Atlantic Ocean and catalogued as “Vulnerable” by the IUCN European assessment. In this study, data on the distribution and population structure of this species across the islands of the Canarian archipelago, located along an east to west gradient in the north‐eastern Atlantic, were collected by taking advantage of “Local Ecological Knowledge,” in terms of sightings in coastal waters and long‐term imprints on the local gastronomic heritage, and decadal fisheries landings. Both sources of quantitative data (sightings and fisheries landings) demonstrated that adults of M. mustelus has a significantly larger presence in the eastern and central, than in the western islands of the archipelago. This is also reflected on local gastronomic legacies, with a larger number of recipes in the eastern and central islands. Adult smooth‐hound sharks were significantly more observed in sandy and sandy‐rocky bottoms, with individuals seen throughout the entire year, whereas juveniles aggregate on very shallow waters in spring and summer. Such aggregations require a special management strategy, as they play a key role in critical life stages; these sites should be protected from human perturbations. We also suggest a temporal fishing ban between April and October, when individuals tend to concentrate on nearshore waters. Because of the large differences in presence of this shark among the Canary Islands, management of the species should be adapted to the specific peculiarities of each island, rather than adopting a management policy at the entire archipelago‐scale. Overall, this study sets the basis for further investigation to promote conservation of this vulnerable shark in the study region.     

Variation of the mitochondrial DNA control region in the populations of southern form of Dolly Varden (<Emphasis Type="Italic">Salvelinus malma krascheninnikovi</Emphasis>) from Sakhalin

Analysis of a 551-bp segment of the mitochondrial DNA control region in 23 individuals from nine populations of Dolly Varden from Sakhalin and three individuals from the Shikaribetsu Lake (Hokkaido) revealed the presence of seven haplotypes of southern form, along with one haplotype of northern form of Dolly Varden. All seven haplotypes of southern Dolly Varden were earlier described in the populations from Hokkaido. Hierarchical analysis of molecular variance (AMOVA) based on the haplotype frequencies, performed using literature data, suggested that, during the glacial epoch, there were three regional population groups of Dolly Varden (from eastern and western coasts of Sakhalin, and from Southern Primorye). Population groups from Sakhalin and Primorye were clearly separated. The differences between two Sakhalin population groups in the mtDNA haplotype frequencies were not statistically significant. However, relative to the earlier obtained data on microsatellite loci, these differences were statistically significant. For the populations of Sakhalin Dolly Varden, the data on mitochondrial and microsatellite DNA variation supplement each other.     

Insights from life history traits of Risso's dolphins (Grampus griseus) in Taiwanese waters: Shorter body length characterizes northwest Pacific population

Risso's dolphins (Grampus griseus) are widely distributed throughout temperate to tropical pelagic waters of the world and are one of the most frequently encountered cetaceans in eastern Taiwanese coastal waters. Because their life history is poorly known, the goal of this study was to investigate the relationship between age, body length, and sexual maturity of Risso's dolphins in Taiwanese waters. Ninety‐two carcasses of dead‐stranded or fisheries bycaught dolphins (1994–2008) were measured and dissected (total body length, TBL 125–290 cm); sexual maturity was assessed in 33 dolphins; and age was estimated by counting dentinal growth layer groups in routine histologically prepared tooth sections of 28 dolphins. Sexual dimorphism in TBL was not detected. The onset of sexual maturity occurred at 240–255 cm in females and 253–265 cm in males, which was at about 10 yr of age for both sexes. Our stranding, bycatch, and previous boat survey records suggest that Risso's dolphins occur year‐round and likely have a summer‐fall calving season in Taiwanese waters. The similar life history parameters and calving season in dolphins from Taiwanese and Japanese waters suggest a common population in the northwest Pacific, which has a noticeably shorter body length than in other regions.     

On the role of dense aggregations of males and juveniles in the functional structure of the range of the blue shark Prionace glauca

Analysis of the quantitative distribution and size composition indicated a high extent of the differentiation of the range of the blue shark Prionace glauca. This most abundant and widely distributed species in the oceanic epipelagial of the entire World Ocean remains for the first years of its life in coastal and neritic waters at depths of 80 m. At the earliest age, at a length under 70 cm, sexes separate into individual schools; females stay nearer to the coast. In the eastern Atlantic, two regions of juvenile habitats are recorded: to the north and to the south of the equator, with a typical gap between them in tropical waters. On reaching a length of 160–190 cm, sharks leave for oceanic waters; immature females follow dense aggregations of adult males situated in oceanic waters where their first mating takes place with a delayed fertilization until reaching sexual maturity. A similar pattern of distribution is traced in the eastern Pacific and other regions of the World Ocean. Under conditions of an increased demand and high prices of shark fins, such aggregations of juveniles and adult males where density exceeds average values dozens of times, can easily lead to overfishing and endanger the species existence and the stability of the structure of the oceanic biota as a whole. The necessity of introducing international protection measures with respect to such aggregations is substantiated.     

Size and age composition of populations and growth of Mytilus trossulus (Bivalvia: Mytilidae) in the subtidal area of western Kamchatka

Fairly large Mytilus trossulus beds were found in the subtidal zone at depths to 40 m off the western coast of Kamchatka. The size and age composition of local populations and growth rates of M. trossulus in this region and at Atlasova Island were studied. Significant variability of the shell shape of mollusks was found. In the western Kamchatka subtidal, M. trossulus grew faster than in the northern Kuril Islands and eastern Kamchatka. Mussels attained commercial size (50 mm in shell length) in the fourth year of life in the former case and in the fifth-sixth year in other cases. Mollusks of different ages, from 1 to 8–9 year olds, were present in western Kamchatka populations; i.e., juvenile recruitment takes place regularly, while growth rates vary. Growth and population structure of M. trossulus are discussed in relation to the habitat conditions on the western Kamchatka shelf.     

Capture of <Emphasis Type="Italic">Hydrolagus</Emphasis> cf. <Emphasis Type="Italic">purpurescens</Emphasis> (Gilbert, 1905) (Chimaeriformes: Chimaeridae) off southeastern Sakhalin

The capture in waters off southeastern Sakhalin of a male of Hydrolagus TL 122 cm is described. It is tentatively identified as Hydrolagus cf. purpurescens, a new species for the fauna and the second representative of the subclass in far eastern waters of Russia. The captured specimen is briefly described and its photographs are published. Unsolved problems of taxonomy of the group purpurescens complex do not permit to make a unanimous determination of this specimen. These problems are discussed and some items concerning the nomenclature of this group are specified.     

An Annotated List of Cartilaginous Fishes (Chondrichthyes: Elasmobranchii,Holocephali) of the Coastal Waters of Sakhalin Island and the Adjacent Southern Part of the Sea of Okhotsk

An annotated list of cartilaginous fish (Chondrichthyes: Elasmobranchii, Holocephali) is given for the first time in the 200-year history of studying the ichthyofauna of Sakhalin Island and adjacent waters of the southern part of the Sea of Okhotsk (including the coast of Hokkaido Island) and the northern Sea of Japan. The list includes 43 species in two classes, eight orders, 16 families, and 25 genera. Information on nature conservation status, English and Latin names, depths of habitat, and distribution within the coastal waters of Sakhalin are presented. For a number of species caught off the coast of Sakhalin and in the adjacent waters, information is provided on collection specimens confirming their presence in the region under study. For a number of species of the Rajiformes order (Arctoraja parmifera, A. smirnovi, A. simoterus), the modern ranges and taxonomic status are being refined in the light of new data. The taxonomic status of the so-called “disputed” taxa is discussed as well as the validity of the species considered in the Bathyraja matsubarai complex. Based on the study of the collections, Arctoraja simoterus, previously unknown in the waters of Russia, as well as Myliobatis tobijei, caught in the Bering Sea, has been discovered, which significantly expands the range of this species to the north.