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Tetsuro?Shiraishi Kohei?Ohta Akihiko?Yamaguchi Mari?Yoda Hisashi?Chuda Michiya?MatsuyamaEmail author 《Fisheries Science》2005,71(3):531-542
ABSTRACT: Final oocyte maturation and ovulation of captive chub mackerel Scomber japonicus with fully yolk-accumulated oocytes were induced by a single injection of human chorionic gonadotropin. Reproductive parameters, including spawning frequency and batch fecundity, which are required to estimate spawning biomass in pelagic fish by the daily egg production method, were analyzed. Germinal vesicle migration (GVM) occurred at 18–24 h post-injection, and the hydration and ovulation of oocytes were completed at 30 and 36 h post-injection, respectively. The results of the maturation process suggest that fish with GVM-stage ovaries captured in the daytime from the field are capable of spawning on the night following their capture. The oocytes used in the oocyte size-frequency distribution method for batch fecundity estimates should be at late GVM and more advanced stages. The results of sequential artificial insemination showed that the quality of ovulated eggs held in the ovarian lumen rapidly deteriorated as time progressed after ovulation. This indicates that the fertilization window for the ovulated eggs of chub mackerel lasts only a few hours, and spawning behavior should be performed within a few hours after ovulation in the wild population. 相似文献
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The spawning grounds of the chub mackerel (Scomber japonicus) and spotted mackerel (Scomber australasicus) in the East China Sea were estimated based on catch statistics of the Japanese large- and medium-type purse seine fishery
from 1992 to 2006. Biometric data were obtained from specimens caught by purse seiners in the East China Sea from 1998 to
2006. Gonadosomatic index (GSI) at 50% sexual maturity of chub mackerel and spotted mackerel females was 2.5 and 2.6, respectively.
Using this criterion for GSI, chub mackerel larger than 275 mm and spotted mackerel larger than 310 mm in fork length were
considered to be mature. Mature chub mackerel was observed in the area of 15–22°C sea surface temperature (SST), and mature
spotted mackerel was observed in the area of 17–25°C SST. The spawning period of chub mackerel ranged from February to June,
and that of spotted mackerel ranged from February to May in the East China Sea. The spawning grounds were estimated from the
distributions of catch per unit effort (CPUE) of spawners and SST. As a result, the spawning ground of chub mackerel was estimated
to be in the central and southern part of the East China Sea and the area west of Kyushu in February, March, and April, and
in the central part of the East China Sea, the area west of Kyushu and Tsushima Straight in May, and in Tsushima Straight
and western part of the Sea of Japan in June. The spawning ground of spotted mackerel was estimated to be in the central and
southern part of the East China Sea and southern coastal area of Kyushu in February, March, and April, and the central and
southern part of the East China Sea and the area west of Kyushu in May. 相似文献
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Nakai M Murata N Yoda T Yoshikawa Y Watanabe K Orino K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(3):313-318
The binding of ferritin to heme has been well studied using commercial horse spleen apoferritin, which is almost entirely composed of the L subunit, suggesting that mammalian ferritins bind heme. The present study revealed that both mammalian holoferritins (commercial horse spleen ferritin and purified horse spleen, bovine spleen and canine liver ferritins with L/H subunit ratios of 4.0, 1.1, and 2.3, respectively) and their apoferritins bound biotinylated hemin; apoferritins had higher binding activity than holoferritins, except for canine holo- and apoferritins, which showed the same binding. Bovine ferritin H subunit homopolymers expressed by a baculovirus expression system showed heme binding and had higher binding activity to biotinylated hemin than the L subunit homopolymer expressed by the same system. These bindings were inhibited by heme but not by iron-free or Zn-protoporphyrin IX (Zn-PPIX). Purified chicken liver holoferritin was found to be composed of only H subunits and showed the highest binding activity with biotinylated hemin compared with mammalian holoferritins. The binding of chicken liver holoferritin to biotinylated hemin was also inhibited by heme but not by PPIX or Zn-PPIX. These results indicate that mammalian and avian ferritins bind heme and that the H subunit preferentially recognizes heme. 相似文献
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Growth and reproductive characteristics of jack mackerel Trachurus japonicus collected in the East China Sea were determined based on otolith readings and gonad histology, respectively. Translucent and opaque zones on sectioned otoliths were identified and opaque rings counted. Von Bertalanffy growth parameters did not significantly differ between males and females, and the combined growth curve was: L t = 401{1 ? exp[?0.275 (t + 1.149)]} (0.8 < t < 6.9), where L t is fork length (mm) at age t. The calculated lengths at age 1 in our study were larger than those reported 50 years ago from the East China Sea. The spawning period was evaluated to be from December to June, but primarily from February to May, based on the monthly changes in the gonadosomatic index and histological observations. The minimum size and age at first maturity were smaller and younger, respectively, than those reported in previous studies. 相似文献
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Mengyao Zhu Takashi Yamakawa Mari Yoda Tohya Yasuda Hiroyuki Kurota Seiji Ohshimo Masa-aki Fukuwaka 《Fisheries Science》2017,83(4):499-513
The abundance index (AI) is a representative indicator used to assess the state of fishery resources. Conventional AI is generally calculated by summing the catch per unit of effort (CPUE) weighted by the size of each fishing area. However, CPUE data has many missing values owing to annual changes in operational fishing areas, and this can lead to a considerable bias in the estimated AI. To obtain an unbiased AI, a multivariate auto-regressive state-space (MARSS) model was used to estimate and interpolate missing values in a spatially arranged, long-term bottom-trawl CPUE dataset for yellow seabream Dentex hypselosomus and largehead hairtail Trichiurus japonicus in the East China Sea. As expected, increasing the number of analyzed fishing grids improved interpolation accuracy, but remarkably increased the time required for the analysis. Reducing the maximum number of expectation–maximization (EM) iterations in the maximum likelihood procedure was an effective way to practically reduce analysis time, while keeping the accuracy of the estimation. Thus, this EM-reduction MARSS model was applied to the entire CPUE datasets of yellow seabream and largehead hairtail to address the annual shifts in their AIs and their seasonal migration. 相似文献
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Jung Jung-Mo Matsushita Yoshiki Hirose Miyuki Sakai Takeshi Kawauchi Yohei Yoda Mari 《Fisheries Science》2021,87(3):263-270
Fisheries Science - We compared the shapes and catches of two trawl nets having differing headrope and groundrope configurations based on paired tow data collected by two research vessels (Yoko... 相似文献
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Two ecotypes of Japanese beech (Fagus crenata Blume), the Pacific Ocean type (PAO) and the Japan Sea type (JAS), show different responses to high solar irradiance. When PAO and JAS saplings were grown in continuous high-light (H), leaves of JAS became pale green. To elucidate this phenomenon, we investigated in vivo photochemistry based on pigment concentrations of Photosystem (PS) I and PS II and Western blot analysis. In JAS-H leaves, the amount of D1-protein decreased, resulting in decreases in the maximal quantum yield of PS II (F(v)/F(m)) and electron transport rate, whereas PAO-H leaves maintained high activities. The PS I photochemistry determined by measurement of P-700 photo-oxidation showed that the intersystem electron pool size was 1.4 times greater in JAS-H leaves than in PAO-H leaves. Furthermore, the re-reduction kinetics of P-700(+) showed that cyclic electron transport around PS I was 1.2 times faster in PAO-H leaves than in JAS-H leaves. Analysis of the area over the fluorescence induction kinetics indicated that the relative abundance of the PS IIalpha center increased in PAO-H leaves, whereas JAS leaves were observed to have low acclimation capacity to high light. These results demonstrate that PAO leaves possess acclimation mechanisms to continuous high light, whereas JAS leaves are more vulnerable to continuous high light, resulting in reduced leaf longevity owing to photoinhibition caused by increases in the intersystem electron pool size and suppression of photochemistry at the level of PS I and PS II. 相似文献