Wiens G.D.,U.S. Department of Agriculture |
Glenney G.W.,Pacific Research Fisheries Center
Developmental and Comparative Immunology | Year: 2011
The tumor necrosis factor superfamily (TNFSF) and the TNF receptor superfamily (TNFRSF) have an ancient evolutionary origin that can be traced back to single copy genes within Arthropods. In humans, 18 TNFSF and 29 TNFRSF genes have been identified. Evolutionary models account for the increase in gene number primarily through multiple whole genome duplication events as well as by lineage and/or species-specific tandem duplication and translocation. The identification and functional analyses of teleost ligands and receptors provide insight into the critical transition between invertebrates and higher vertebrates. Bioinformatic analyses of fish genomes and EST datasets identify 14 distinct ligand groups, some of which are novel to teleosts, while to date, only limited numbers of receptors have been characterized in fish. The most studied ligand is TNF of which teleost species possess between 1 and 3 copies as well as a receptor similar to TNFR1. Functional studies using zebrafish indicate a conserved role of this ligand-receptor system in the regulation of cell survival and resistance to infectious disease. The increasing interest and use of TNFSF and TNFRSF modulators in human and animal medicine underscores the need to understand the evolutionary origins as well as conserved and novel functions of these biologically important molecules. © 2011.
Zavolokin A.V.,Pacific Research Fisheries Center
Journal of Ichthyology | Year: 2011
Based on complex epipelagic surveys in the western Bering Sea, a comparative analysis of food supply of Pacific salmon (Oncorhynchus spp.) was conducted in summer and fall from 2002 to 2006. Nine indirect indices of food supply used in the study were as follows: feeding similarity, width of the feeding spectrum, diet feeding ration, diet feeding rhythms, fraction of accessory food in the ration, growth rate of the fish, abundance of food resources, and abundance of salmon. The food supply of salmon is lower in summer 2003 and fall 2006 in comparison to the food supply in other years of the study. However, well expressed feeding selectivity, consumption of prey items of certain type, and small proportion of accessory food (copepods and chaetognaths) prevailed in plankton, suggests the presence of sufficient food resources for Pacific salmon in the western Bering Sea. © 2011 Pleiades Publishing, Ltd.
Volvenko I.V.,Pacific Research Fisheries Center
Russian Journal of Marine Biology | Year: 2012
In the virtual multidimensional space of integral biocenotic characteristics, such as abundance, the sizes of individuals, and the components of species diversity, which are scaled on corresponding coordinate axes, the points that represent samples from various biocenotic assemblages, form similar multi-layered hill-shaped figures. The examples we considered are the pelagic macrofauna of the Bering Sea, the Sea of Okhotsk, the Sea of Japan and the adjacent waters of the Northwestern Pacific Ocean; the phytoplankton, zooplankton, and zoobenthos of Lake Ladoga, the Neva Bay, and the Gulf of Finland in the Baltic Sea; the beetle guild in the rainforest of Borneo Island on the Malay Archipelago; and the bird taxocenes and biotope groups of soil mites in North America, among others. The obvious similarity of the composed diagrams results from the close interrelationships of all the integral characteristics and also from the universality of the structure of links between them, which is tolerant to movements in the real space-time continuum and invariant towards the subject of the studies. The multidimensional domain of the analyzed variables is a set of points that are aggregated along a segment, whose length and orientation relative to the coordinate axes determine the general rules of the biocenotic organization of the living matter. © 2012 Pleiades Publishing, Ltd.
Volkov A.F.,Pacific Research Fisheries Center
Russian Journal of Marine Biology | Year: 2012
The mass occurrence of the large hyperiid Themisto libellula was recorded in both the western and the eastern Bering Sea within 2007-2011. Those were the years of a relatively long 6-year period of cold, which was caused mainly by the inflow of cold waters from the north; this is confirmed by the distribution of bottom and surface temperatures and also by the ice-cover values. This hyperiid became dominant in the diet of salmon, walleye pollock, herring, and several other nekton fish species. T. libellula periodically spreads southward with cold northern waters, finding favorable conditions in "new" areas. Being a rapidly growing species with a short life cycle, within 1 or 2 years it reaches a high abundance, which then gradually declines and remains at a mean or low level, as usually occurs with species that were introduced into a new habitat. After the environmental conditions deteriorate, as a "warm" period arrives with changes in the general circulation and a growing inflow of warmed Pacific waters, the southern boundary of the species range moves back far northward and it completely disappears in the areas where it prevailed in the plankton and was a main forage item in the diet of many fish species. Taking into account the durations of warm and cold periods from 1980 until 2010, an event like this in the Bering Sea can be expected within 1 or 2 years. In the eastern Bering Sea, the abundance and dominance of a number of zooplankton species may vary simultaneously. This effect is more pronounced in T. libellula and for this reason the species is considered as a biological indicator of the described climatic changes in the Bering Sea. © 2012 Pleiades Publishing, Ltd.
Zavolokin A.V.,Pacific Research Fisheries Center
Russian Journal of Marine Biology | Year: 2010
The seasonal and interannual trends in the distribution and abundance of jellyfish (Scyphozoa and Hydrozoa) in the epipelagic and mesopelagic areas of the Sea of Okhotsk during 1992-2005 were examined on the basis of trawl survey data. The area of occurrence, biomass, and the numbers of Scyphozoa in the epipelagic layer were the smallest in spring; in summer and fall their abundance sharply increased and then decreased in winter. In contrast to the epipelagic zone, the numbers of scyphomedusae in the mesopelagic layer were significantly lower in the summer than in the winter and spring. This probably indicates that a part of scyphomedusae winter in the mesopelagic. Hydrozoa in both the epi- and mesopelagic areas were more numerous in the winter and spring. Jellyfish biomass and abundance greatly changed from year to year. Thus, in fall the biomass of scyphomedusae and hydromedusae in the epipelagic zone varied from 166 to 1271 and from 6 to 49 kg/km2, respectively. © Pleiades Publishing, Ltd 2010.
Hirpo L.A.,Pacific Research Fisheries Center
Livestock Research for Rural Development | Year: 2012
Food and feeding habits of Carassius carassius in Melkawakena reservoir were studied. Samples of C. carassius were collected monthly during August (2009) through to July (2010) using gillnets of different mesh sizes. C. carassius was found to ingest a variety of organisms of plant and animal origins, as well as items including detritus and sand grains. However, insects, zooplankton and phytoplankton were found to be the most important food of the fish in the reservoir. Thus, the fish is considered to have a mainly omnivorous feeding habit. The major food items ingested were insects when the size of the fish is increase. However, the importance of phytoplankton and zooplankton tended to decrease where as that of insect tended to increase with the length of C. carassius. Thus, it appeared that the fish feeds progressively more insect as it grows larger. High incidence of empty stomachs was observed during the whole sampling period. But, the frequency of empty stomach was high during the rainy season, which could be associated with breeding activity.
Allen S.,Pacific Research Fisheries Center
Pacific Science | Year: 2013
Fish stocks in many parts of the western Pacific are increasingly being subjected to a variety of environmental and human pressures. Resource managers are responding to the situation by limiting and allocating catch across the various fisheries. There is a corresponding need to appropriately classify fishers and fishing fleets to ensure that all sectors are fairly considered when catch allocation decisions are undertaken in the region. But discrete classification of small-scale fishing sectors is challenging because commercial, recreational, and food-gathering motives often overlap. Moreover, despite the known importance of small-scale fishing in the western Pacific, the manner and extent of such activities are not well understood or thoroughly documented. This paper seeks to elucidate the nature of subsistence or consumption-oriented fishing and its relationship to other forms of small-scale fishing activities in the region. A conceptual framework of potential utility for assessing the degree to which small-scale operations are moving toward or away from subsistence fishing is developed with the intent of optimizing the resource allocation decision-making process. The discussion is based on review of pertinent literature and on findings from research recently conducted in Hawai'i and the Commonwealth of the Northern Mariana Islands. © 2013 by University of Hawai'i Press All rights reserved.
Jay C.V.,U.S. Geological Survey |
Fischbach A.S.,U.S. Geological Survey |
Kochnev A.A.,Pacific Research Fisheries Center
Marine Ecology Progress Series | Year: 2012
The Pacific walrus Odobenus rosmarus divergens feeds on benthic invertebrates on the continental shelf of the Chukchi and Bering Seas and rests on sea ice between foraging trips. With climate warming, ice-free periods in the Chukchi Sea have increased and are projected to increase further in frequency and duration. We radio-tracked walruses to estimate areas of walrus foraging and occupancy in the Chukchi Sea from June to November of 2008 to 2011, years when sea ice was sparse over the continental shelf in comparison to historical records. The earlier and more extensive sea ice retreat in June to September, and delayed freeze-up of sea ice in October to November, created conditions for walruses to arrive earlier and stay later in the Chukchi Sea than in the past. The lack of sea ice over the continental shelf from September to October caused walruses to forage in nearshore areas instead of offshore areas as in the past. Walruses did not frequent the deep waters of the Arctic Basin when sea ice retreated off the shelf. Walruses foraged in most areas they occupied, and areas of concentrated foraging generally corresponded to regions of high benthic biomass, such as in the northeastern (Hanna Shoal) and southwestern Chukchi Sea. A notable exception was the occurrence of concentrated foraging in a nearshore area of northwestern Alaska that is apparently de - pauperate in walrus prey. With increasing sea ice loss, it is likely that walruses will increase their use of coastal haul-outs and nearshore foraging areas, with consequences to the population that are yet to be understood. © Inter-Research 2012.
Panchenko V.V.,Pacific Research Fisheries Center
Journal of Ichthyology | Year: 2012
Age and growth have been studied in four species of staghorn sculpins of the genus Gymnocanthus inhabiting Primorye (the Russian sector of the Sea of Japan). Large black edged and purplegray sculpins, G. herzensteini and G. detrisus, inhabited deeper waters compared with threaded sculpin G. pistilliger and (especially) whip sculpin G. intermedius. The size differences between different sculpin species could already be revealed in the diameter of mature oocytes and the length of hatching larvae and fries passing to the benthic phase of development. The maximum size in these species correlated with their maximum age. G. herzensteini, G. detrisus, G. pistilliger, and G. intermedius could attain the age of no less than 16+, 15+, 9+, and 7+, respectively. The gains in fish of the same age were also greater in species attaining greater size values. In all the species, females lived longer than males and were larger than males of the same age. Throughout the life cycle, the growth rate gradually came down; the decrease was especially pronounced during the period of sexual maturation. In the southern part of the geographic range, the specimens of purplegray sculpin attained smaller size and showed lower growth rate compared with the fish from the northern part of the range. The threaded sculpin demonstrated the inverse relationships. In general, females were dominating in samples of staghorn sculpins; however in small and medium size groups, the proportion of males was greater, which was due to their smaller, compared with females, absolute gains. In elder groups, the proportion of males gradually went down, as they were dying earlier than females. © 2012 Pleiades Publishing, Ltd.
Savin A.B.,Pacific Research Fisheries Center
Journal of Ichthyology | Year: 2012
Biomass of bottom and near-bottom fishes in the eastern Sea of Okhotsk has been calculated using results of a bottom trawl survey performed in the summer 2010 through depths of 200-1000 m. Obtained data are compared with the results of investigations performed in compatible water areas during the same season of 1989 and 1997. Biomass variability patterns of major species have been revealed for the period of more than two recent decades. The bathymetric and spatial distribution of major fish species has been revealed using the modern information. Species are listed whose commercial catches could be enlarged. © 2012 Pleiades Publishing, Ltd.