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At least 19 recordsLinked to original sources
PubMedDate not supplied

[Monogenea in 2 species of fish of the order of the garfish (Beloniformes) from the Indian and Pacific Oceans].

Two fish species, Euleptorhamphus viridis and Cololabis saira, were studied for monogeneans. 284 specimens of E. viridis collected in nearly all parts of its area in the Indian and Pacific Oceans have been examined. Five species of monogeneans were found in this species: Axine parini, Axinoides kola, Diplaxine popovae and two species of gastrocotylid larvae. None of them were recorded in E. viridis before. In both oceans the infection of E. viridis with Axine parini and Gastrocotylidae g. sp. I larvae was the most extensive. In the Indian Ocean the infection extensiveness of E. viridis with A. parini was higher than in the Pacific. The areas of all parasites were more restricted than that of the host. None of 190 specimens of the saury had any monogeneans.

Animals↗
PubMedDate not supplied

[Total number, biomass and production of bacteria in the water of the subtropical and equatorial-tropical regions of the Pacific Ocean].

The total number and biomass of bacteria were determined by capillary microscopy in 168 samples of water taken from different horizons (0-5,000 m) in the subtropic and equatorial-tropic regions of the central part of the Pacific Ocean (135 degrees and 150 degrees w. long) and the western half of the Indian Ocean (65 degrees e. long). In most cases, 1 ml of water contained dozens and hundreds of thousands of the cells whose biomass was several or dozens milligrams per 1 m3. Layers with a high content of bacteria were encountered not only in the surface zone but also at large depths. In the euphotic layer (0-200 m), the mean value of the bacterial biomass was similar to that of phytoplankton in mesotrophic waters of tropic divergences and subpolar zones. Vertical distribution of the total number of the microorganisms was found to be similar to distribution of saprophytic bacteria studied earlier.

Bacteria↗
PubMed2026

Bacterial extracellular vesicles exhibit distinct functional potential across biogeographic provinces of the South Pacific Ocean.

Bacterial extracellular vesicles (BEVs) are nanoscale membranous structures released by diverse types of bacteria, and are capable of transporting and delivering biological compounds between cells. Experimental investigation of BEVs in laboratory model systems indicates that these nanoparticles may play a number of roles in the ecophysiology of marine bacterial communities, but their functional potential in the environment remains unclear. Here we describe the proteomic composition of BEV populations over more than 5000 nautical miles of surface waters in the South Pacific, linking BEV cargoes to the bacterial communities producing them. The presence of marine BEVs was consistently observed across a range of biogeochemical conditions, with an overall abundance comparable to that of bacterial cells (up to 108 BEVs L-1). The protein cargo of marine BEVs, however, differed significantly among ocean regions. The BEV populations were enriched in carbohydrate transporters under phytoplankton bloom conditions, and contained iron uptake-related proteins in nutrient-limited waters. These data suggest that BEVs could enable cells to perform key extracellular functions in the marine environment. Our observations highlight the ubiquity of marine BEVs and biogeographic patterns in their ecological potential across oceanic scales.

Extracellular Vesicles↗
PubMed2026

Genomics Detects Japanese and Pacific Sardine (Sardinops spp.) Hybrids in the Northeast Pacific Ocean.

Sardine (Sardinops spp.) are ecologically important forage fishes distributed globally across temperate, coastal upwelling zones and, when abundant, they support major fisheries. Previous genomic analyses of Pacific Sardine (S. sagax) in the Northeast Pacific detected the presence of Japanese Sardine (S. melanosticta), a species typically found in the Northwest Pacific, along the west coast of North America starting in 2022 over multiple years. To facilitate continued monitoring, we developed a highly accurate species identification Genotyping-in-Thousands-by-sequencing (GT-seq) panel consisting of 88 single nucleotide polymorphisms (SNPs). This panel was constructed by utilizing low-coverage, whole-genome sequence data to identify highly divergent, genome-wide loci between Pacific and Japanese Sardine, enabling unambiguous identification of these morphologically indistinguishable species as well as the detection of hybrids. Using the novel panel, we genotyped 1821 sardine samples from the Northeast Pacific and identified 35 hybrid individuals, which were collected from 2023 to 2025 and are the first known observation of such hybrids. Most were F1 hybrids (33); however, two individuals collected in 2025 appeared to be backcrosses with S. sagax. Our newly developed panel is a powerful resource for the continued monitoring of Japanese Sardine in the Eastern Pacific and is critical for investigating the potential fitness consequences of hybridization with Pacific Sardine.

Journal Article↗
PubMed1977

[Biochemical polymorphism in the northern fur seal, Callorhinus usinus, from 3 regions of the northwestern part of the Pacific Ocean].

Polymorphism for the number of the blood proteins (transferrin, alkaline phosphatase, haptoglobin, plasma esterase and erythrocyte esterase) have been exposed by means of starch gel electrophoresis of northern fur seal Callorhinus ursinus from three regions: Pelagic of Commander Islands (n = 164), Rockery of Robben Island (Sakhalin population, n = 308), winter todder region to the east of Honshu Island (n = 110). The reliable differences have been exposed between fur seals of the Commander and Sakhalin populations by the gene frequencies Tf and Es pl. Fur seals from winter todder region turned out to be closer to Commander population, that to the Robben one. However, originality of gene frequencies of locus Ap (alkaline phosphatase), revealed from the todder region animals, is difficult to explain by the mixture of the Commander and Robben population only. Perhaps, this originality is caused by the influence of Pribylov population. It is established that hemoglobin of northern fur seal consists of two components (Hb I + Hb II). Individual variability of hemoglobin results in the variation of the colour intensity of the "slow" component (Hb II).

Alkaline Phosphatase↗
PubMed1975

Biochemical polymorphism of starry flounder, Platichthys stellatus, from the northwestern and northeastern Pacific Ocean.

Three enzyme systems, MDH, PGM and AGPDH, were investigated in starry flounder collected from off northwestern Hokkaido Island, Japan; western Kamchatka; USSR; Puget Sound, Washington, USA; and Yaquina Bay, Oregon, USA. Significant differences in MDH allele distribution were found between the Asian-Puget Sound and Yaquina Bay-Puget Sound samples suggesting that this system may be useful to separate different population units. The allele frequencies of MDH and PGM did not show significant variation with body length and handedness in starry flounder collected from Puget Sound, Washington, and did not support the hypothesis of differential viability between dextral and sinistrial forms of starry flounder.

Adaptation, Biological↗
PubMed2026

Integrating genomic distance analyses in the description of a new family, genus, and species of sponge-associated antipatharians (black corals).

Antipatharians (black corals) are among the least studied coral groups, with much of their diversity still undescribed. Here, we present an integrative morphological, phylogenomic and genomic distance study of deep-sea antipatharians sampled in high seas areas of the North Pacific Ocean and from New Zealand's Exclusive Economic Zone. These corals grow on hexactinellid sponges - a unique characteristic in the order Antipatharia. Using a dataset of ultra-conserved elements and exons, combined with morphological analyses, we reconstruct phylogenomic relationships and formally describe a new family (Eidikopathidae fam. nov.), a new genus (Eidikopathesgen. nov.), and two new species (E. korallispongiasp. nov., E. zealandkoralliasp. nov.). Morphologically, the new family is distinguished by a corallum consisting of a network of loose branches that fuse with the sponge skeletal framework. Phylogenomic analyses recovered consistent topologies with strong nodal support, corroborating the distinct evolutionary placement of this sponge-associated lineage. Pairwise genomic distances estimated using the Tamura-Nei model were concordant with patristic genomic distances, identifying Pteridopathidae as the genetically closest family to Eidikopathidae fam. nov., followed by Myriopathidae and Stylopathidae, which were recovered as sister families in the phylogeny. This pattern shows that genomic distance complements, rather than simply mirrors, tree topology by quantifying accumulated sequence divergence among lineages. Together, these results provide the first genomic distance framework for Antipatharia, offering a baseline for future systematic, evolutionary, and biodiversity studies on this fundamental shallow, mesophotic and deep-sea coral group.

Animals↗
PubMed2025

Biogeographic Structure and Mitonuclear Discordance Reveal Cryptic Diversity in Pacific Herring (Clupea pallasii).

Forage fishes are biological drivers throughout the Pacific Ocean, from the Arctic to nearly subtropical latitudes. As a critical trophic link, the health and stability of Pacific herring (Clupea pallasii) populations have implications for other marine species, including several targeted by large, productive fisheries. Previous research has indicated marked divergence between Pacific herring in the Bering Sea and the Gulf of Alaska. Seeking to localize this biogeographic break, we generated low-coverage whole genome resequencing data for 120 Pacific herring from seven sites across the northern Gulf of Alaska and the eastern Bering Sea and Aleutian Islands. Single nucleotide polymorphisms across the mitogenome (267) and nuclear genome (~5.6 million) corroborate a biogeographic break in Pacific herring along the Alaska Peninsula and Aleutian Islands, as far west as Unalaska. We identified two distinct populations: one exists along the northern coasts of the Aleutian Islands and in the eastern Bering Sea; the other occupies the southern edge of the Aleutians and the Gulf of Alaska. Two mitochondrial haplogroups co-occurring across the Gulf of Alaska suggest secondary contact between two populations, likely representing glacial refugia. Our results underscore the importance of geological events to contextualize the diversification of forage fish species.

Bering Sea↗
PubMed1992

Direct sequencing of mitochondrial DNA detects highly divergent haplotypes in blue marlin (Makaira nigricans).

We were able to differentiate between species of billfish (Istiophoridae family) and to detect considerable intraspecific variation in the blue marlin (Makaira nigricans) by directly sequencing a polymerase chain reaction (PCR)-amplified, 612-bp fragment of the mitochondrial cytochrome b gene. Thirteen variable nucleotide sites separated blue marlin (n = 26) into 7 genotypes. On average, these genotypes differed by 5.7 base substitutions. A smaller sample of swordfish from an equally broad geographic distribution displayed relatively little intraspecific variation, with an average of 1.3 substitutions separating different genotypes. A cladistic analysis of blue marlin cytochrome b variants indicates two major divergent evolutionary lines within the species. The frequencies of these two major evolutionary lines differ significantly between Atlantic and Pacific ocean basins. This finding is important given that the Atlantic stocks of blue marlin are considered endangered. Migration from the Pacific can help replenish the numbers of blue marlin in the Atlantic, but the loss of certain mitochondrial DNA haplotypes in the Atlantic due to overfishing probably could not be remedied by an influx of Pacific fish because of their absence in the Pacific population. Fishery management strategies should attempt to preserve the genetic diversity within the species. The detection of DNA sequence polymorphism indicates the utility of PCR technology in pelagic fishery genetics.

Amino Acid Sequence↗
PubMedDate not supplied

Kinetic approach to the study of primary production in the ocean.

Theoretical arguments for and experimental verification of the kinetic approach to the study of primary production in the ocean are described. According to some kinetic models the increase in pure primary production in the ocean is proportional not to time, but approximately to the square root of time. Calculation of the pure primary production of the Pacific Ocean, according to data in the literature, allowing for kinetic correction, gives a value of the order of 7 x 10(9)-10 x 10(9) tons CO2 per annum, equivalent to about 10% of the global pure primary production in the present-day biosphere, calculated from seasonal fluctuations in CO2 in the atmosphere. The existence of polycircadian cycles of function of oceanic phytoplankton is demonstrated.

Atmosphere↗
PubMed1992

20-Hz pulses and other vocalizations of fin whales, Balaenoptera physalus, in the Gulf of California, Mexico.

Low-frequency vocalizations were recorded from fin whales, Balaenoptera physalus, in the Gulf of California, Mexico, during three cruises. In March 1985, recorded 20-Hz pulses were in sequences of regular 9-s interpulse intervals. In August 1987, nearly all were in sequences of doublets with alternating 5- and 18-s interpulse intervals. No 20-Hz pulse sequences of any kind were detected in February 1987. The typical pulse modulated from 42 to 20 Hz and its median duration was 0.7 s (1985 data). Most other fin whale sounds were also short tonal pulses averaging 82, 56, and 68 Hz, respectively, for the three cruises; 89% were modulated in frequency, mostly downward. Compared to Atlantic and Pacific Ocean regions, Gulf of California 20-Hz pulses were unique in terms of frequency modulation, interpulse sound levels, and temporal patterns. Fin whales in the Gulf may represent a regional stock revealed by their sound characteristics, a phenomenon previously shown for humpback whales, birds, and fish. Regional differences in fin whale sounds were found in comparisons of Atlantic and Pacific locations.

Animal Communication↗
PubMedDate not supplied

[Hydrocarbon-oxidizing microflora of uncontaminated seawater].

The distribution of hydrocarbon-oxidizing microflora in noncontaminated sea waters was studied in the northern region of the Pacific Ocean in the vicinity of the Copper Island. The total number of microorganisms was assayed as well as the number of heterotrophic, oligocarbophilic and hydrocarbon-oxidizing microorganisms. Oligocarbophilic bacteria were the most abundant group (from 120 to 24,000 cells per 1 ml), and predominated in 12 stations among 23. The number of heterotrophic organisms was not great and did not exceed 200 cells per 1 ml in 13 stations. A solid medium with an oil product (1%) which was used to determine the number of hydrocarbon-oxidizing bacteria gave overstated results due to the growth of oligocarbophilic forms that could survive in the presence of high hydrocarbon concentrations in the medium. A silica gel medium with an oil product is recommended. Despite the absence of oil contaminations in littoral waters, hydrocarbon-oxidizing bacteria were found in all samples and their content was high in some stations. This can be accounted for by the variety of nutrient requirements of these microorganisms and, apparently, by the presence in water of high molecular weight aliphatic lipids inding the capacity to oxidize hydrocarbons. Organisms belonging to the genera Mycobacterium and Arthrobacter prevailed among hydrocarbon-oxidizing bacteria.

Hydrocarbons↗
PubMed1977

Geographic variations in tumor prevalence among marine fish populations.

A global epidemiological study on the frequency of skin papillomas among various flatfish species (Pleuronectids), papillomas of eels and the virus induced lymphocystis disease has revealed particular distribution patterns. Skin papillomas are prevalent among at least 20 flatfish species of the northern Pacific Ocean, Bering Sea, Sea of Okhotsk, and Japan Sea but appear to be absent from the Atlantic, North Sea, and the Caribbean Sea. The opposite is found for lymphocystis, which is common among flatfish species of the Atlantic shores of Europe and North America. Similarly the skin papillomas of eels are restricted to relatively small region along the European coast extending from the Baltic countries to Denmark, Germany and Holland. Superimposed on this global distribution pattern are local variations in tumor prevalences which can vary from about 58% to 0.01%. The geographic distribution pattern points to the existence of areas around the globe in which flatfish or eels are able to develop skin papillomas. Outside these areas of "potential skin papilloma risk," flatfish and eel populations are not afflicted with papillomas even if they inhabit estuaries or rivers with a high man-made or naturally-occurring pollution.

Animals↗
PubMed1975

Taxonomic difficulties in red tide and paralytic shellfish poison studies: the "tamarensis complex" of Gonyaulax.

The type illustrations of the dinoflagellate Gonyaulax tamarensis contain an apparent reversal of the epithecal plates. Furthermore a culture from the type locality has been found not to be toxigenic. These two features have led a recent author to doubt the appropriateness of the allocation of toxic populations in the North Atlantic to this species or a variety of it (var. excavata Braarud). The latter has been raised to the status of a distinct species but the wrong name has been applied to it (G. excavata) as, according to the rules of priority, it should be G. phoneus (Woloszynska & Conrad) nov. comb. A history of this confused situation is provided. The criteria by which other similar species are recognised are summarised. The necessity for further study on the specific distinction of these taxa is stressed. G. conjuncta has been so inadequately described or rejected. Variability in the plate pattern of a culture of G. tamarensis var. excavata from British Columbia is illustrated and its bearing on the taxonomy of the group discussed. The presence of this toxic variety on the west coast of N. America is a new record for the Pacific Ocean.

Animals↗