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1.
Information about the sites of catches of the sea lamprey Petromyzon marinus in the western Barents Sea and Arctic lamprey Lethenteron camtschaticum in the Barents and White seas is presented based on the data of trawl surveys performed in 2004?2016. It is demonstrated that sea lamprey is occasionally encountered in the western Barents Sea; nine specimens have been recorded during the entire period of surveys. The northernmost point of a capture of sea lamprey is located near 76° N and the easternmost point is at 31°15′ E. Arctic lamprey is not numerous in the Barents and White seas; a total of 66 and 17 specimens have been caught, respectively. Its local aggregations are found in the southeastern part of the Barents Sea and in Dvina Bay in the White Sea. Arctic lamprey penetrates to the north to 76° N and into the central part of the Barents Sea.  相似文献   

2.
Cardinal fish are commercially valuable species. In the Colombian Caribbean Sea E. occidentalis and E. pandionis occurred in 37and 35% of tows during a research trawl survey (>200 m), respectively and the biology of these vulnerable species is unknown. The aim of this work is to describe the spatial distribution patterns of biomass, size structure and morphometric relationships of E. occidentalis and E. pandionis in deep waters of the Colombian Caribbean Sea. The samples were collected by trawling in depths between 200 and 550 m. No statistical differences were found in size by sexes in both species. In female and male E. occidentalis the growth was isometric, while in female and male E. pandionis it was positive allometric. E. occidentalis occurred mainly in the northern zone of Colombian Caribbean Sea, with highest aggregations off Santa Marta and Riohacha. E. pandionis was distributed in the northern area between Santa Marta and Riohacha and in the southern area between Cartagena and Morrosquillo Gulf. However, before the exploitation of these species is considered, further research is required to determine basic life history traits, such as growth, reproduction, recruitment, and mortality.  相似文献   

3.
Based on the data of benthic surveys of 2010–2012, three benthic communities: a shallow-water community with the dominance of Scoloplos spp., Nucula tennuis, and Scalibregma inflatum; a deep-water community with the dominance of Chaetosone sp.; and a community of mixed sediments, have been distinguished in soft sediments in marine lakes Sisjajarvi and Linjalampi. These communities are typically marine and similar to other communities in shallow areas of the Barents Sea. They mostly differ in a high abundance of the polychaete Scalibregma inflatum and a small number of echinoderms from the communities in other bays of the Barents Sea. The abundance of the polychaete S. inflatum indicates indirectly possible cases of anoxia in Lake Sisjajarvi.  相似文献   

4.
Pacific herring, Clupea pallasii, have recently colonised the northeast Atlantic and Arctic Oceans in the early Holocene. In a relatively short evolutionary time, the herring formed a community with a complex population structure. Previous genetic studies based on morphological, allozyme and mitochondrial DNA data have supported the existence of two herring subspecies from the White Sea and eastern Barents and Kara Seas (C. p. marisalbi and C. p. suworowi, respectively). However, the population structure of the White Sea herring has long been debated and remains controversial. The analyses of morphological and allozyme data have previously identified local spawning groups of herring in the White Sea, whereas mtDNA markers have not revealed any differentiation. We conducted one of the first studies of microsatellite variation for the purpose of investigating the genetic structure and relationship of Pacific herring among ten localities in the White Sea, the Barents Sea and the Kara Sea. Using classical genetic variance-based methods (hierarchical AMOVA, overall and pairwise F ST comparisons), as well as the Bayesian clustering, we infer considerable genetic diversity and population structure in herring at ten microsatellite loci. Genetic differentiation was the most pronounced between the White Sea (C. p. marisalbi) versus the Barents and Kara seas (Chesha–Pechora herring, C. p. suworowi). While microsatellite variation in all C. pallasii was considerable, genetic diversity was significantly lower in C. p. suworowi, than in C. p. marisalbi. Also, tests of genetic differentiation were indicating significant differentiation within the White Sea herring between sympatric summer- and spring-spawning groups, in comparison with genetic homogeneity of the Chesha–Pechora herring.  相似文献   

5.
Molecular genetic and karyological analyses of antlered sculpin, Enophrys diceraus, from the Sea of Japan and the Sea of Okhotsk were carried out. The karyotype of this species was studied for the first time. On the basis of karyological analysis, it was established that E. diceraus from the Sea of Japan and the Sea of Okhotsk was polymorphic in terms of the number of chromosomes and their morphology (2n = 36, 35, and 37, NF = 40). It was suggested that the karyotype with 35 chromosomes could have been produced as a result of Robertsonian translocation; the karyotype with 37 chromosomes could have been produced by crossing of individuals with different number of chromosomes. On the basis of the molecular genetic analysis of the mitochondrial COI and 16S rRNA genes, considerable differences between E. diceraus from the Sea of Japan and the Sea of Okhotsk corresponding to the level of interspecies genetic variability were established. It is concluded that E. diceraus from the Sea of Japan belongs to another species, most likely, E. namiyei.  相似文献   

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7.
A rust fungus was found on the leaves of Euphorbia helioscopia during a field study in Pakistan. Previously, Melampsora euphorbiae, M. euphorbiae-gerardianae and M. helioscopiae have been reported on E. helioscopia, the first two of which are also known from Pakistan. Morphological observations of the newly collected rust samples detected some differences from the previously described Melampsora species on E. helioscopia. The molecular analysis of the ITS and LSU sequences also detected that the rust is different from the previously reported rusts described from E. helioscopia. Based on both morphological comparisons and sequence analysis, the rust is described here as M. pakistanica sp. nov. This species could have potential as a bio-control agent against its host plant—E. helioscopia—which is a weed of wheat fields in Pakistan and elsewhere in the world.  相似文献   

8.
Six species that belong to the diatom genus Attheya were found in the Russian waters of the Sea of Japan. A. cf. flexuosa is a new record for the seas of Russia. A. decora is recorded for the first time for the Sea of Japan. The peculiarities of the morphology of A. decora and A. cf. flexuosa are described and illustrated. The study of the seasonal distribution, abundance, and ecology of Attheya species in the northwestern Sea of Japan showed that A. longicornis and A. ussurensis were the most numerous and widespread species, reaching maximum densities (up to 1.5 × 106 and 1.8 × 104 cells/liter, respectively) in the spring, summer, and fall. A. cf. flexuosa and A. septentrionalis were rare and were found in low numbers in the winter and early spring. Based on the ultrastructure of the girdle bands, the form and number of chloroplasts, the presence/absence of rimoportula on the valve, and habitat features, we distinguished two groups of species of the genus Attheya from the Sea of Japan. The first group includes psammophytes A. decora, A. arenicola, and A. ussurensis; the second one comprises A. longicornis and A. cf. flexuosa epiphytic on other diatoms, as well as A. septentrionalis, which is found in the under-ice plankton and is able to attach to the underside of ice.  相似文献   

9.
High level of intraspecific polymorphism of the mtDNA cytochrome b gene in the Atlantic cod Gadus morhua L. from the northeastern part of the species range (Barents and White seas) is detected. The absence of genetic differentiation between the samples from different areas of the Norwegian and Barents seas is shown, and the fact that these samples belong to the same population of Northeast Arctic cod is confirmed. Significant differences in the frequences of mitochondrial DNA haplotypes between the cod from the Barents and White seas, as well as from the northwestern part of the range, are found. The cod Gadus morhua kildinensis Derjugin, 1920 from Mogilnoye Lake and Gadus morhua marisalbi Derjugin, 1920 from the White Sea were revealed to have common haplotypes with the cod from the Barents Sea, confirming the recent origin of these forms from the Atlantic cod G. morhua.  相似文献   

10.
Pacific herring (Clupea pallasii) is divided into three subspecies: two in northeast Europe and one in the north Pacific Ocean. Genetic studies have indicated that the populations in northeast Europe have derived from the northwest Pacific herring recently, or during the last 10–15 kyr, and that they are distinct from the population in the northeast Pacific. In addition, hybridization between the Pacific herring and the Atlantic herring has been documented. Otolith variation has been considered to be largely affected by environmental variation, but here we evaluate whether the genetic differentiation is reflected in otolith shape differences. A clear difference in otolith shape was observed between the genetically differentiated herring species Clupea harengus from the Atlantic and C. pallasii. The otolith shape of C. p. suworowi in the Barents Sea was different from the shape of C. pallasii in northern Norway and C. p. pallasii from the Pacific. Populations of C. p. pallasii, sampled east and west of the Alaska Peninsula, which belong to two genetically different clades of the C. p. pallasii in the Pacific Ocean, show a clear difference in otolith shape. C. p. suworowi and the local C. pallasii peripheral population in Balsfjord in northern Norway are more similar to the northwest Pacific herring (C. p. pallasii) than to the northeast Pacific herring (C. p. pallasii), both genetically and in otolith shape. The Balsfjord population, known to be influenced by introgression of mtDNA from the Atlantic herring, does not show any sign of admixture in otolith shape between the two species. A revised classification, considering the observed genetic and morphological evidence, should rather group the northwest Pacific herring in the Bering Sea together with the European populations of C. pallasii than with the northeast Pacific herring in the Gulf of Alaska.  相似文献   

11.
The genus Eckhardites Mitta 1999, with the type species Macrocephalites pavlowi Smorodina, 1928 is discussed and its diagnosis and assignment to the family Cardioceratidae are substantiated. Eckhardites is compared to the genus Macrocephalites Zittel (family Sphaeroceratidae), to which some workers presently assign the type species of Eckhardites. Three species of Eckhardites are recorded from the basal Callovian elatmae Zone of the Russian Platform, one of which (E. menzeli (Mönnig)) was originally described from the synchronous beds in Germany. A new species E. dietli sp. nov. is described.  相似文献   

12.
A new species, Melanostigma olgae sp. n., is described from the Southern Ocean. The type series was obtained along the South Sandwich Islands (Scotia Sea, Western Antarctic) at the depths of 800?850 m. The new species differs from the other representatives of Melanostigma genus by the original combination of the features of the seismosensory system, axial skeleton, and coloration. The homologization of the structural elements (senses) of the head canals of the lateral line has been done for the first time for the Melanostigma. Morphology of M. olgae allows considering this species as the most evolutionary advanced within the representatives of this genus inhabiting the Southern Ocean. The key of the Antarctic species of the genus Melanostigma is provided.  相似文献   

13.
A total of 18 polymorphic microsatellite loci were isolated and characterized from RAPD products in the Xinjiang Arctic Grayling (Thymallus arcticus grubei). The number of alleles (Na) per locus varied from 2 to 10. Observed (Ho) and expected (He) heterozygosities ranged from 0.64 to 0.92, and from 0.63 to 0.88, respectively. Considerable differences were found among HBH, FH and FY populations in the number of alleles, effective number of alleles, number of genotypes at all of these loci. These new RAPD-SSR markers have provided a helpful tool for genetic analyses and resources conservation of T. arcticus grubei. Five additional fish species, Amur grayling (Thymallus grubii), Taimen (Hucho taimen), Sea perch (Lateolabrax japonicus), Lenok (Brachymystax lenok) and Red seam bream (Pagrosomus major) were assessed for cross-species amplification. Three of the five species showed at least one polymorphic locus. In addition, seven loci were found to be polymorphic in at least one species.  相似文献   

14.
15.
Red king crab (Paralithodes camtschaticus) was introduced into the Barents Sea in the 1960–1970s. At present, it occurs along the coast from Hammerfest (Northern Norway) to the (northeastern coast of Kola Peninsula). We studied the polymorphism of a mitochondrial gene encoding cytochrome oxidase (COI) and five nuclear microsatellite loci in four samples from the Barents Sea and two donor populations from the Western Kamchatka and Primorye (Russian Pacifics). No decrease in the genetic diversity of the introduced populations was observed. The results of PCA103 locusanalysis but some samples from the Barents Sea significantly differed from the Pacific populations according to the test for population differentiation demonstrated that the sample from Varrangerfjord was highly significantly different from the other five populations. As no significant differences between the other samples were found at this locus. We consider it to be a marker for Varangerfjord population differentiation. Possible reasons of this phenomenon are discussed.  相似文献   

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18.
Ten new species of the genera Eurytoma (8 species) and Tetramesa (2 species) from Yemen are described (Eurytoma lahji Zerova, E. thoraxica Zerova, E. cyrtophorae Zerova, E. longipes Zerova, E. yemeni Zerova, E. mabari Zerova, E. tibiaspinae Zerova, E. longitarsis Zerova, Tetramesa sanai Zerova, and T. rujumi Zerova). The type specimens of the new species are deposited in the collection of the Institute of Zoology, National Academy of Sciences of Ukraine, Kiev.  相似文献   

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20.
Based on light and scanning electron microscopical studies, a new nematode parasite, Pseudodelphis eleginopsis n. sp. (Dracunculoidea: Guyanemidae), is described from tissues behind the gills of the Patagonian blennie Eleginops maclovinus (Cuvier) (Perciformes: Eleginopsidae) off the Atlantic coast (San Matías and San José Gulfs) of Patagonia, Argentina. The new species is mainly characterised by the length of the body (males 10–13 mm, larvigerous females 31–59 mm), the number (14) and arrangement of cephalic papillae, the absence of a buccal capsule, the muscular to glandular oesophagus length ratio (1:3–4) of larvigerous females, the length of the spicules (48–63 µm) and the number (7 pairs) and arrangement of the caudal papillae in the male. Pseudodelphis eleginopsis n. sp. is the first species of this genus described from a marine fish in the Atlantic Ocean and the first known dracunculoid parasitising the fish host belonging to the family Eleginopsidae. As revealed by the examination of very young females of the new species, the female genital tract of Pseudodelphis spp. is monodelphic. The genus Syngnathinema Moravec, Spangenberg & Frasca, 2001 is considered a junior synonym of Pseudodelphis Adamson & Roth, 1990 and, consequently, S. californiense and S. chitwoodi are transferred to Pseudodelphis as P. californiensis (Moravec, Spangenberg & Frasca, 2001) n. comb. and P. chitwoodi (Moravec & Kuchta, 2013) n. comb., respectively. Two dracunculoid species, Pseudodelphis limnicola Brugni & Viozzi, 2006 and the previously established Philonema percichthydis Moravec, Urawa & Coria, 1997, both described from the same freshwater host species, Percichthys trucha (Valenciennes), in the same region (Patagonia), are considered to be identical; therefore, the valid name of this species is Pseudodelphis percichthydis n. comb. and P. limnicola becomes its junior synonym. A key to the species of Pseudodelphis is provided.  相似文献   

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