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ABSTRACT: Stranded organisms were observed on the sandy beach of Kuroshima Island, Ryukyu Archipelago, in the early morning of 28 January 1993. Stranded organisms of 525 individuals were classified into 74 species. These organisms included 13 individuals of Panulirus pueruli, which were identical to P. longipes bispinosus. Kuroshima Island is located near Ishigakijima and Iriomote islands, Ryukyu Archipelago, where coral reefs develop. Coral reefs are common and develop in the Ryukyu Archipelago, southern Japan, with the exception of Yakushima and Tanegashima islands. Panulirus japonicus in Japanese waters has not been found in coral reef regions where P. longipes bispinosus are mainly found. The present study describes and identifies to species level puerulus specimens that were stranded on the beach of Kuroshima Island. 相似文献
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In the coastal zone of the Sea of Okhotsk off Hokkaido, Japan, the giant ezo scallop ( Patinopecten yessoensis ) is widely cultivated on the sea bed, making its fishery a major industry. However, the area experiences intense cyclones, including typhoons, about once a decade and the scallop resources appear to have received severe damage from the storms. Such an event occurred on 29 October 1988. The storm caused 12-m-high wind waves, which appeared to be fully developed sea waves. The water above the sea bed repeatedly moved back and forth at speeds of 1∼2 m s-1 causing damage to the scallops due to collisions and rubbing with gravel and other scallops. From a comparison of wind data with the annual catch of scallops, intense cyclones seem to play an important role on the year-to-year fluctuations in the scallop fishery. 相似文献
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RAMJI KUMAR BHANDARI IKUO USHIKOSHI HIDEO FUKUOKA NOBUHISA KOIDE KOHEI YAMAUCHI HIROSHI UEDA 《Fisheries Science》2002,68(4):776-782
ABSTRACT: The filamentous fungi Rhizopus , like many fungal species, possesses physiologically active substances. Rhizopus extract (RU) is reported to be effective for various aspects of growth and reproduction in many vertebrates. The effects of RU administration on body growth and plasma levels of steroid hormones were investigated in lacustrine sockeye salmon Oncorhynchus nerka . One-year-old fish were fed daily with RU (20 mg/kg feed) from July 1999 to October 2000 for 15 months. Fish were sampled every month and plasma levels of testosterone (T), 11-ketotestosterone (11-KT), estradiol-17β (E2 ) and 17α,20β-dihydroxy-4-pregnen-3-one (DHP) were measured by time-resolved fluoroimmunoassay. Body growth of RU-fed fish of both sexes increased significantly in 1+ and 2+ October, and 2+ January–March and July. All RU-fed males and one female matured in 2+ October. RU-fed 1+ precociously mature males showed increased plasma levels of T, 11-KT and DHP in 1+ October. In 2+ males, RU significantly elevated plasma levels of T from May to June, 11-KT from June to July, and DHP in October. In sockeye salmon, administration of RU accelerated body growth of both sexes and sexual maturation in males, suggesting physiologically active substances present in RU enhance somatic growth and sexual maturation by sex-specific mechanisms. 相似文献
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Oogenesis in the common Japanese conger Conger myriaster 总被引：1，自引：0，他引：1
TOMOKO UTOH NORIYUKI HORIE AKIHIRO OKAMURA YOSHIAKI YAMADA SATORU TANAKA NAOMI MIKAWA ATSUSHI AKAZAWA HIDEO P OKA 《Fisheries Science》2003,69(1):181-188
ABSTRACT: We investigated the process and characteristics of oogenesis in the common Japanese conger Conger myriaster . Young fish caught in November 1996 were reared for use in this experiment. Fish were sampled monthly from December 1997 to August 1998. Some were injected with human chorionic gonadotropin to stimulate ovarian maturation from May to August 1998. Oocytes from the chromatin nucleolus stage to the secondary yolk globule stage were obtained from non-hormone-treated fish; those of more advanced stages were obtained from hormone-treated ones. We divided oocyte development into eight stages from the chromatin nucleolus stage to the maturation stage. The yolk vesicle stage was not separated because yolk vesicles began to appear just after appearance of yolk globules. Oocyte, oil droplet, yolk globule and nucleus diameters all increased concomitant with oocyte development. Oil droplet and yolk globule diameters increased remarkably at the maturation stage. However, zona radiata thickness peaked at the secondary yolk globule stage, decreasing gradually thereafter. Increased gonadosomatic index was related to oocyte development as found in European and Japanese eels receiving hormone treatment to mature. The present study is the first report describing oogenesis characteristics in congrid eels. It indicates that oogenesis is almost identical to that of other anguillid eels. 相似文献
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Resistance of Venturia nashicola to thiophanate-methyl and benomyl: build-up and decline of resistance in the field 总被引：1，自引：1，他引：0
Changes in the proportion of benzimidazole-resistant strains in populations of Venturia nashicola were monitored in pear orchards. Successive applications of thiophanate-methyl increased the level of resistance in the populations. When the application of benzimidazoles was stopped and other fungicides were applied, the proportion of highly resistant strains gradually decreased and the proportion of intermediately resistant, weakly resistant and sensitive strains increased. It is suggested that this phenomenon is an example of genetic homeostasis within microbial populations. 相似文献
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Weed control with alfalfa pellets in transplanting rice 总被引：1，自引：1，他引：1
TRAN DANG XUAN EIJI TSUZUKI HIDEO UEMATSU HIROYUKI TERAO 《Weed Biology and Management》2001,1(4):231-235
Alfalfa [ Medicago sativa L. ( M. media , M. falcate )] plants contain allelochemicals that have detrimental effects on their own growth and that of surrounding plants. Alfalfa pellets, used as a food for livestock, were used as the material for the control of weeds in this study. In a greenhouse experiment, alfalfa pellets applied at 1–3 tons ha−1 completely inhibited the emergence of abunome ( Doparium junceum Hamilt.), false pimpernel ( Lindernia pyxidaria L.), and long stemmed water wort ( Elatine trianda Schk. var. pedicellata Krylov) The number and the dry weight of emerged Echinochloa oryzicola plants were significantly reduced. Application of 3 tons ha−1 alfalfa pellets completely inhibited the emergences of Eleocharis acicularis and Rotala indica. Results demonstrated that the inhibitory effect of alfalfa pellets became greater as the dose increased, and it also varied among weed species. Furthermore, the paddy field experiment suggested that the dose of 1–2 tons ha−1 of alfalfa pellets could control more weed species without any rice plant injury. 相似文献
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NORIYUKI HORIE TOMOKO UTOH YOSHIAKI YAMADA AKIHIRO OKAMURA HUAN ZHANG NAOMI MIKAWA ATSUSHI AKAZAWA SATORU TANAKA HIDEO P OKA 《Fisheries Science》2002,68(5):972-983
Development of embryos and larvae in the common Japanese conger Conger myriaster was observed after artificial fertilization. Eggs were obtained from females matured artificially by hormone injections and milt was obtained from males matured naturally. Fertilized eggs were kept in seawater at 12–14°C. The first cleavage occurred at 4 h, epiboly began at 24 h, the embryonic body was formed at 38 h and hatching occurred at 84 h after insemination. Newly hatched larvae were approximately 2.5 mm (total length) and similar to those of Anguilla japonica in terms of external features. The mouth and anus opened on the 7th day after hatching. Pigments began to appear at the tip of the tail on the 10th day. The total length of the larvae reached approximately 8 mm on the 11th day. Eye pigmentation began on the 14th day. One larva lived for 19 days without food. 相似文献
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