Morphobiological Difference and Reproduction Peculiarities of Pink Salmon Oncorhynchus gorbuscha from Two Rivers in the Northeastern Part of Sakhalin Island

Journal of Ichthyology - Morphobiological indices and reproduction peculiarities of the pink salmon Oncorhynchus gorbuscha have been studied for the specimens sampled in two rivers of the...     

Larvae of phoronids (Phoronida) from Terpeniya Bay (Southeastern Sakhalin)

Phoronid larvae were found in planktonic samples from the northern coast of Terpeniya Bay. In some samples, their density was up to 220 specimens/m³. Larval stages having 10, 12, 16, 20, and 22 tentacles are described. Larvae were identified as Actinotrocha branchiata and belong to the species Phoronis muelleri Selys-Longchamps, 1903. However, unlike the Ph. muelleri larvae described in the literature, the larvae we found are smaller (not more than 900 μm) before metamorphosis and have fewer tentacles (24). They lack paired vacuolated diverticula of the stomach, which are characteristic of Ph. muelleri larvae. However, judging by all other characters, namely transparency, the absence of coelomic cylinder in the preoral lobe, and the presence of adult tentacle primordia, one pair of blood cell aggregations, and a pyriform organ, these larvae are similar to the previously described larvae of Ph. muelleri. Adult forms of Ph. muelleri were previously found in Terpeniya Bay and described by Mamkaev (1962) and Emig (1984).     

Intertidal Communities of Severnyi Bay (Northern Sakhalin Island)

The paper describes the composition, structure and vertical distribution of intertidal communities in Severnyi Bay (the northern extremity of Sakhalin Island).     

Patterns of Downstream Migration of Pink Salmon Oncorhynchus gorbuscha in the Malaya Khusi River (Sakhalin Oblast)

Journal of Ichthyology - Patterns of downstream migration of juvenile pink salmon Oncorhynchus gorbuscha in the Malaya Khusi River (northeast of Sakhalin island) are revealed as a result of...     

Genetic Diversity of the Pink Salmon Oncorhynchus gorbuscha (Walbaum) from Some Rivers of Northeastern Russia

Biology Bulletin - Data on the variability of the mtDNA nucleotide sequence of cytochrome b of pink salmon from successive generations were obtained. There was a higher level of divergence between...     

Captures of Pacific Rainbow Smelt Osmerus dentex (Osmeridae) in the Langery River (North-East of Sakhalin Island)

Journal of Ichthyology - The article describes captures of three specimens of the Pacific rainbow smelt Osmerus dentex in the area of the north-east of Sakhalin Island, where the species was not...     

On the Issue of Life Strategy Formation in Pacific Salmon of the Genus Oncorhynchus (Salmonidae)

Journal of Ichthyology - Data on life strategies of Pacific salmon of the genus Oncorhynchus are reviewed, and possible mechanisms of their realization in the ontogeny are discussed. Reproductive...     

Chromosome Transfer from Pink Salmon (Oncorhynchus gorbuscha) to Masu Salmon (O. masou)

Sperms from Pink salmon were subjected to incomplete irradiation by γ-ray to cause partial breakageof their chromosome. Normal eggs from masu salmon were fertilized by these damaged sperms andput under hydrostatic pressure to suppress the release of second polar bodies. The resultant eggscontained complete sets of genome from masu salmon and some chromosomes and chromosomefragments from pink salmon. Karyotype and isozyme of the embryos were analyzed. The resultsdemonstrate that the chromosomes from pink salmon showed genetic activities. Variations in hatchedindividuals were observed.     

Abundance and Distribution of Pelagic Larvae of Bivalves and Echinoderms in Busse Lagoon (Aniva Bay,Sakhalin Island)

The taxonomic composition and numbers of pelagic larvae of bivalves in Busse Lagoon and the contiguous areas of Aniva Bay (southern Sakhalin) were studied in 2000–2001. In comparison with 1973–1974, the total density of larvae increased 2–3 times, but their taxonomic composition changed and a redistribution of dominant species occurred. Numbers of bivalve larvae increased at the expense of larvae of Musculista senhousia, Crassostrea gigas, and species of the Tellinidae. In 2000–2001, larvae of Ruditapes philippinarum, Mya arenaria, Swiftopecten swifti, and some other species were encountered in plankton very rarely or were not found at all. The drastic decrease in the larval density of some bivalve species was caused by uncontrolled and nearly total harvesting of mollusks. Larval echinoderm numbers in the lagoon were not high in 2000–2001; larvae of the sea cucumber Apostichopus japonicus and the sea urchin Strongylocentrotus intermedius predominated.     

Proteomic Analysis of Chinook Salmon (Oncorhynchus tshawytscha) Ovarian Fluid

The ovarian, or coelomic, fluid that is released with the egg mass of many fishes is increasingly found to play an important role in several biological processes crucial for reproductive success. These include maintenance of oocyte fertility and developmental competence, prolonging of sperm motility, and enhancing sperm swimming speed. Here we examined if and how the proteome of chinook salmon (Oncorhynchus tshawytscha) ovarian fluid varied among females and then sought to examine the composition of this fluid. Ovarian fluid in chinook salmon was analyzed using 1D SDS PAGE and LC-MS/MS tryptic digest screened against Mascot and Sequest databases. We found marked differences in the number and concentrations of proteins in salmon ovarian fluid across different females. A total of 174 proteins were identified in ovarian fluid, 47 of which were represented by six or more peptides, belonging to one of six Gene Ontology pathways. The response to chemical stimulus and response to hypoxia pathways were best represented, accounting for 26 of the 174 proteins. The current data set provides a resource that furthers our understanding of those factors that influence successful egg production and fertilisation in salmonids and other species.     

Some Population Dynamics Issues of Pink Salmon Oncorhynchus gorbuscha Temporal Forms on Sakhalin and the Southern Kuril Islands

Journal of Ichthyology - Population dynamics of early and late temporal forms of pink salmon Oncorhynchus gorbuscha on the Iturup and Kunashir islands (southern Kuril Islands) and on the...     

Fossil Wolffish (Anarhichadidae) From the Miocene Deposits of Sakhalin Island

Journal of Ichthyology - In the deposits of the Middle–Late Miocene of the deep-water Kurasi Formation of Southwestern Sakhalin, a destroyed skeleton of the wolffish head Anarhichadidae gen....     

The Comparative Characteristics of Naturally Produced and Hatchery-Reared Juvenile Pink Salmon,Oncorhynchus gorbuscha (Walbaum, 1792), from Sakhalin Oblast

Russian Journal of Marine Biology - The body size and weight characteristics were analyzed and the morpho-physiological condition of the system of internal organs was studied in wild juvenile pink...     

Active Outcome of Pink Salmon Oncorhynchus gorbuscha (Salmonidae) Fry into the Water Current for Passive Downstream Migration

Journal of Ichthyology - Field experiments and observations revealed that active outcome of pink salmon fry Oncorhynchus gorbuscha into the riverine water current precedes its passive downstream...     

New Species of Oribatid Mites (Acari,Oribatida) from Sakhalin Island

Entomological Review - Two new oribatid mite species collected in the park zone of Yuzhno-Sakhalinsk (Sakhalin Island, Russia) are described. Xenillus similis sp. n. is a large pale brown mite with...     

Dispersal Potential is Affected by Growth-Hormone Transgenesis in Coho Salmon (Oncorhynchus kisutch)

Potential ecological consequences on the natural environment of fast‐growing transgenic fish with elevated intrinsic growth rates is an important question should such fish be allowed in commercial production systems. One trait that will strongly affect the spatial extent of consequences is the propensity of transgenic fish to disperse. We addressed this question in three experiments using different measures of spatial dispersal where we compared very young genotypically wild coho salmon with transgenic conspecifics in terms of: (i) group cohesion, (ii) exploratory behavior, and (iii) up‐ and downstream movements. Transgenic fish were more loosely aggregated, more likely to explore, and less likely to swim upstream, but equally likely to disperse downstream compared with genetically wild fish. These results show that dispersal behavior has been affected by transgenesis and that transgenic fish therefore may venture into habitats previously not used by wild fish. Given the importance of dispersal in ecological risk‐assessment of transgenic fish, continued work within this area is warranted and experimental habitats should mimic the potential receiving natural habitats to which transgenic fish are likely to escape or be released to.     

Coho Salmon (Oncorhynchus kisutch) Prefer and Are Less Aggressive in Darker Environments

Fish are capable of excellent vision and can be profoundly influenced by the visual properties of their environment. Ambient colours have been found to affect growth, survival, aggression and reproduction, but the effect of background darkness (i.e., the darkness vs. lightness of the background) on preference and aggression has not been evaluated systematically. One-hundred Coho salmon (Oncorhynchus kisutch), a species that is increasing in popularity in aquaculture, were randomly assigned to 10 tanks. Using a Latin-square design, every tank was bisected to allow fish in each tank to choose between all the following colour choices (8 choices in total): black vs. white, light grey, dark grey, and a mixed dark grey/black pattern, as well as industry-standard blue vs. white, light grey, dark grey, and black. Fish showed a strong preference for black backgrounds over all other options (p < 0.01). Across tests, preference strength increased with background darkness (p < 0.0001). Moreover, having darker backgrounds in the environment resulted in less aggressive behaviour throughout the tank (p < 0.0001). These results provide the first evidence that darker tanks are preferred by and decrease aggression in salmonids, which points to the welfare benefits of housing farmed salmon in enclosures containing dark backgrounds.