156 research outputs found

    Genetic and morphological differences between Sebastes vulpes and S. zonatus (Teleostei: Scorpaeniformes: Scorpaenidae)

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    The taxonomic status of Sebastes vulpes and S. zonatus were clarified by comprehensive genetic (amplif ied fragment length polymorphisms [AFLP] and mitochondrial DNA [mtDNA] variation) and morphological analyses on a total of 65 specimens collected from a single locality. A principal coordinate analysis based on 364 AFLP loci separated the specimens completely into two genetically distinct groups that corresponded to S. vulpes and S. zonatus according to body coloration and that indicated that they are reproductively isolated species. Significant morphological differences were also evident between the two groups; 1) separation by principal component analysis based on 31 measurements, and 2)separation according to differences in counts of gill rakers and dorsal-fin spines without basal scales, and in the frequencies of specimens with small scales on the lower jaw. Restriction of gene flow between the two groups was also indicated by the pairwise ΊST values estimated from variations in partial sequences from the mtDNA control region, although the minimum spanning network did not result in separation into distinct clades. The latter was likely due to incomplete lineage sorting between S. vulpes and S. zonatus owing to their recent speciation

    Taxonomic review of the Sebastes pachycephalus complex (Scorpaeniformes: Scorpaenidae)

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    A taxonomic review of the Sebastes pachycephalus complex established the existence of two valid species, S. pachycephalus and S. nudus. Similarities between them include: cranium armed dorsally with robust preocular, supraocular, postocular, and parietal spines; interorbital space concave; lower jaw lacking scales, shorter than upper jaw; thickened rays in ventral half of pectoral fin; dorsal fin usually with 13 spines and 12 soft-rays; pored lateral line scales 27–35 (usually 29–33). However, S. pachycephalus is distinguishable from the latter in having minute scales below the entire dorsal-fin spine base (vs. lacking minute scales below first to fifth or variously to the posteriormost spine in the latter), dark spots scattered on the dorsal, anal and caudal fins (vs. no distinct dark spots), and lacking distinct colored markings on the dorsum (vs. yellow or reddish-brown markings present). Although both species occur off the southern Korean Peninsula and in the Bohai and Yellow Seas, in Japanese waters, the former is distributed from northern Honshu Is. southward to southern Kyushu Is., whereas the latter extends from southern Hokkaido southward along the Pacific coast of Japan to Kanagawa, and along the Sea of Japan coast to northern Kyushu Is., including the Seto Inland Sea. Sebastes nigricaus, S. nigricans, and S. latus are confirmed as junior synonyms of S. pachycephalus, and S. chalcogrammus as junior synonym of S. nudus, based on the examination of type specimen

    Snailfishes of the Careproctus rastrinus complex (Liparidae): redescriptions of seven species in the North Pacific Ocean region, with the description of a new species from the Beaufort Sea.

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    Herein we review and recognize as valid all previously described species of the Careproctus rastrinus complex based on morphological evidence, provide diagnoses and descriptions of all species, describe a new species from the Beaufort Sea, and address the misapplication of several names throughout the area. In particular, the name C. rastrinus is restricted to populations of the western Pacific and is known conclusively only from the Sea of Okhotsk. Careproctus acanthodes, from the Sea of Japan and Sea of Okhotsk, and C. pellucidus, from the Pacific Ocean side of northern Japan, are resurrected from synonymy with C. rastrinus. Populations of the eastern Pacific previously routinely identified as C. rastrinus are recognized under two names: C. scottae, a name that is applied to deeper water Bering Sea, Aleutian Islands, and eastern Pacific populations having a postorbital pore, and Careproctus phasma, applied to shallow water populations of the Bering Sea and Gulf of Alaska lacking a postorbital pore. Although we consider Careproctus spectrum valid, the species has been routinely misidentified and is presently known only from the type series. Careproctus lerikimae is a new species described from the Beaufort Sea, diagnosed from other species of the C. rastrinus complex by the absence of the postorbital pore and higher median fin and vertebral counts

    Fish assemblages associated with three types of artificial reefs: density of assemblages and possible impacts on adjacent fish abundance

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    We evaluated the effectiveness of wooden artificial reefs (ARs) as fish habitat. Three types of ARs, made of cedar logs, broadleaf tree logs, and PVC pipes, respectively, were deployed in triplicate at 8-m depth off Maizuru, Kyoto Prefecture, Sea of Japan, in May 2004. Fish assemblages associated with each of the nine ARs were observed by using SCUBA twice a month for four years. Fish assemblages in the adjacent habitat were also monitored for two years before and four years after reef deployment. In the surveyed areas (ca. 10 m2) associated with each of the cedar, broadleaf, and PVC ARs, the average number of fish species was 4.14, 3.49, and 3.00, and the average number of individuals was 40.7, 27.9, and 20.3, respectively. The estimated biomass was also more greater when associated with the cedar ARs than with other ARs. Visual censuses of the habitat adjacent to the ARs revealed that the number of fish species and the density of individuals were not affected by the deployment of the ARs. Our results support the superiority of cedar as an AR material and indicate that deployment of wooden ARs causes no reduction of fish abundance in adjacent natural reefs

    Taxonomic review of the deep water flathead genus Parabembras with description of the new species Parabembras multisquamata from the western Pacific Ocean (Teleostei, Parabembridae)

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    Three valid species of Parabembras are recognized: P. curta, P. robinsoni, and the new species P. multisquamata. Parabembras robinsoni from the southwestern Indian Ocean (South Africa to Mozambique) is easily distinguishable from the other species in having eleven spines in the first dorsal fin, a distinct symphyseal knob on the lower jaw, two preocular spines, and a single lachrymal spine. Parabembras multisquamata from the southwestern Pacific (Vanuatu, Papua New Guinea) and the Philippines, and P. curta, known from the northwestern Pacific (southern Japan to South China Sea), are similar in sharing the absence of a symphyseal knob on the lower jaw, the presence of two lachrymal spines, and a single preocular spine, but the former is clearly distinguished from the latter in usually having 10 spines in the first dorsal fin (vs. eight or nine spines in P. curta), 9–11 supraocular spines (vs. 6–8 in P. curta), 40–44 pored lateral line scales (vs. 34–39 in P. curta), and the pectoral fin extending beyond the level of the anus (vs. not reaching to the level of the anus in P. curta)

    Recurrent Erythema Nodosum in a Child with a SHOC2 Gene Mutation

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    We report the case of a 6-year-old male who developed recurrent erythema nodosum (EN) at the age of 3 years. The patient exhibited hypertelorism, low-set ears, micrognathia, moderate intellectual disability, thin long fingers, loose anagen hair, and prominent palmoplantar wrinkles. A heterozygous single nucleotide variant in the SHOC2 gene (c.4 A > G, p.S2G) was identified. Patients with a SHOC2 mutation exhibit a unique combination of ectodermal abnormalities including darkly pigmented skin and loose anagen hair. This report is the first to describe EN in a patient with SHOC2 mutation, and to examine the patient’s hair using scanning electron microscopy. We hypothesize that the RAS/MAPK pathway is associated with the pathogenesis of cutaneous lesions in patients with SHOC2 mutations via autoinflammation and disturbance of epithelial stem cells

    EMPRESS. IX. Extremely Metal-Poor Galaxies are Very Gas-Rich Dispersion-Dominated Systems: Will JWST Witness Gaseous Turbulent High-z Primordial Galaxies?

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    We present kinematics of 6 local extremely metal-poor galaxies (EMPGs) with low metallicities (0.016−0.098 Z⊙0.016-0.098\ Z_{\odot}) and low stellar masses (104.7−107.6M⊙10^{4.7}-10^{7.6} M_{\odot}). Taking deep medium-high resolution (R∌7500R\sim7500) integral-field spectra with 8.2-m Subaru, we resolve the small inner velocity gradients and dispersions of the EMPGs with Hα\alpha emission. Carefully masking out sub-structures originated by inflow and/or outflow, we fit 3-dimensional disk models to the observed Hα\alpha flux, velocity, and velocity-dispersion maps. All the EMPGs show rotational velocities (vrotv_{\rm rot}) of 5--23 km s−1^{-1} smaller than the velocity dispersions (σ0\sigma_{0}) of 17--31 km s−1^{-1}, indicating dispersion-dominated (vrot/σ0=0.29−0.80<1v_{\rm rot}/\sigma_{0}=0.29-0.80<1) systems affected by inflow and/or outflow. Except for two EMPGs with large uncertainties, we find that the EMPGs have very large gas-mass fractions of fgas≃0.9−1.0f_{\rm gas}\simeq 0.9-1.0. Comparing our results with other Hα\alpha kinematics studies, we find that vrot/σ0v_{\rm rot}/\sigma_{0} decreases and fgasf_{\rm gas} increases with decreasing metallicity, decreasing stellar mass, and increasing specific star-formation rate. We also find that simulated high-zz (z∌7z\sim 7) forming galaxies have gas fractions and dynamics similar to the observed EMPGs. Our EMPG observations and the simulations suggest that primordial galaxies are gas-rich dispersion-dominated systems, which would be identified by the forthcoming James Webb Space Telescope (JWST) observations at z∌7z\sim 7.Comment: Submitted to ApJ; After revisio

    The Ganymede Laser Altimeter (GALA) for the Jupiter Icy Moons Explorer (JUICE): Mission, science, and instrumentation of its receiver modules

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    The Jupiter Icy Moons Explorer (JUICE) is a science mission led by the European Space Agency, being developed for launch in 2023. The Ganymede Laser Altimeter (GALA) is an instrument onboard JUICE, whose main scientific goals are to understand ice tectonics based on topographic data, the subsurface structure by measuring tidal response, and small-scale roughness and albedo of the surface. In addition, from the perspective of astrobiology, it is imperative to study the subsurface ocean scientifically. The development of GALA has proceeded through an international collaboration between Germany (the lead), Japan, Switzerland, and Spain. Within this framework, the Japanese team (GALA-J) is responsible for developing three receiver modules: the Backend Optics (BEO), the Focal Plane Assembly (FPA), and the Analog Electronics Module (AEM). Like the German team, GALA-J also developed software to simulate the performance of the entire GALA system (performance model). In July 2020, the Proto-Flight Models of BEO, FPA, and AEM were delivered from Japan to Germany. This paper presents an overview of JUICE/GALA and its scientific objectives and describes the instrumentation, mainly focusing on Japan’s contribution
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