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Habitat use and movement patterns of small (age‐0) juvenile Pacific bluefin tuna (Thunnus orientalis) relative to the Kuroshio 
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下载免费PDF全文 Ko Fujioka Hiromu Fukuda Seishiro Furukawa Yaoki Tei Suguru Okamoto Seiji Ohshimo 《Fisheries Oceanography》2018,27(3):185-198
The habitat use of Pacific bluefin tuna (Thunnus orientalis; PBF) in nursery waters off the southern coast of Japan was investigated using archival tags over a 3 year study period (2012–2015), and the data were used to examine the free‐ranging habitat preferences of PBF and the relationship between their horizontal movements and the path of the Kuroshio off the Pacific coast of Japan. The path of the Kuroshio fluctuated seasonally, leading to changes in water temperature that strongly influenced the habitat use of small PBF (2–3 months after hatching). Most PBF were present in coastal waters inshore of the path of the current, and their habitat use changed in response to the distance of the current from the coast. The Kuroshio typically flowed along the coast from summer to autumn, and PBF remained in the coastal waters off Kochi Prefecture during this period. In contrast, PBF quickly moved eastward in winter when the current moved away from the coast. Throughout the winter and spring, the area of habitat use extended widely from the eastern end of the southern coast of Japan (the Boso Peninsula) to the offshore Kuroshio‐Oyashio transition region. These findings suggest that the seasonal habitat use and movement behavior of juvenile PBF are influenced by the distance of the Kuroshio axis from the coast, and the ultimate drivers are likely variations in oceanographic conditions and prey availability along the southern coast of Japan. 相似文献
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Seishiro Taki Yoshihiro Nobori Maximo Larry Lopez Caceres 《Journal of Forest Research》2014,19(1):226-232
We derived a formula for estimating the relationship between stem carbon weight and stem volume, which was calculated from DBH and tree height using a combination of stem analysis and soft X-ray densitometry. The results indicate carbon weight in a 33-year-old coastal Japanese black pine (Pinus thunbergii) forest is approximately 68,186 kg ha?1 in Yamagata Prefecture and 38,253 kg ha?1in a 42-year-old black pine forest in Hokkaido Prefecture, Japan. Also, age-related changes in the stem density following oven-drying of samples of black pine trees are small: the oven-dried density (hereafter “density”) of black pine trees in the two locations mentioned above were 425.6 (kg m?3) and 523.2 (kg m?3) respectively, which is comparable to the density (converted from basic density) of black pine of Land Use, Land-Use Change and Forestry (LULUCF) (533 kg m?3). When compared with the carbon weight by the oven-dried density of LULUCF, the carbon weights calculated from each density were 27 % lower in Yamagata and 6 % lower in Hokkaido. This difference directly affects carbon weight for large-scale estimation and thus can create an error at a regional scale. This methodology can contribute to the management of forests acting as carbon sinks. 相似文献
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Seishiro Furukawa Seiji Ohshimo Seitaro Tomoe Tetsuro Shiraishi Naoyuki Nakatsuka Ryo Kawabe 《Fisheries Science》2012,78(6):1153-1162
The growth and reproductive characteristics of dolphinfish Coryphaena hippurus collected in the waters off western Kyushu from May 2008 to April 2011 were determined based on scale and otolith readings and gonad histological examinations, respectively. Based on annual increments in scales and daily increments in sagittal otoliths, the von Bertalanffy growth curves in male and females were determined as $ FL_{t} = 1049[1 - \exp \{ - 0.835(t + 6.975 \times 10^{ - 14} )\} ] $ and $ FL_{t} = 938[1 - \exp \{ - 1.029(t + 6.975 \times 10^{ - 14} )\} ] $ , respectively, where FL t is the mean fork length (mm) at age t. The spawning period was found to last from June to August for dolphinfish, based on an examination of the monthly changes in the gonadosomatic index and histological observations. Therefore, based on the relationship between the fork length and the developmental stage of the testes or ovaries, male and female dolphinfish were found to reach sexual maturity by the following spawning season after hatching in the northern East China Sea. 相似文献
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Itoh N Ikegami H Takagi M Ito Y Kanai K Chikazawa S Hori Y Hoshi F Higuchi S 《Journal of Feline Medicine and Surgery》2012,14(6):436-439
The present study is the first national investigation of intestinal parasites in private-household cats in Japan. A total of 942 faecal samples were collected from private-household cats. Giardia species was assessed using an enzyme-linked immunosorbent assay kit and other intestinal parasites were identified microscopically. The overall prevalence of intestinal parasites was 10.1%; two protozoan parasites (Giardia species and Cystoisospora species) and five helminths (Toxocara cati, Toxascaris leonina, Ancylostoma tubaeforme, Taenia species and Spirometra erinacei) were detected. The total prevalence of intestinal parasite infection was significantly higher in cats aged ≤ 6 months old than in cats older than 6 months because of a significantly higher prevalence of Cystoisospora species and T cati. The total infection prevalence was higher among outdoor cats as a result of the significantly higher prevalence of T cati and S erinacei. Sex and faecal condition were not related to intestinal parasite infections. Regional differences were observed in Cystoisospora species and A tubaeforme. 相似文献
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Seishiro CHIKAZAWA Yasutomo HORI Fumio HOSHI Kazutaka KANAI Naoyuki ITO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(7):843-846
In the present study, we examined the relationship between serum ferritin concentration
before treatment and survival time in dogs with multicentric lymphoma. Eighteen dogs with
multicentric lymphoma were enrolled in the study. When the dogs were classified into high
and low ferritin groups on the basis of their serum ferritin concentration (3,000
ng/ml cut-off value), the median survival time of dogs
with high concentrations (≥3,000 ng/ml, n=7) was 40
days, whereas it was 360 days among dogs with low concentrations (<3,000
ng/ml, n=11). This difference was statistically
significant (P=0.001). This finding suggests that the initial high level
of serum ferritin indicates short survival time in dogs with multicentric lymphoma.
Large-scale research is necessary to confirm this finding. 相似文献
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