权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Biology and effects of cartilaginous fishes on fisheries in the Sagami Bay

相模湾软骨鱼类的生物学及其对渔业的影响

基本信息

批准号：
14560163
负责人：
TANIUCHI Toru
金额：
$ 2.56万
依托单位：
Nihon University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

The total number of 21 species of cartilaginous fishes were collected from the depth below 150 m in the Sagami Bay during the course of the present study. Three triakid species were provided by fishermen. Among those species, most abundant species was Squalus mitsukurii, making up 69% of the total catch of 442 specimens captured by R/V Enoshima-maru belonging to Kanagawa Prefectural Fisheries Research Center. Other species constituted less than 10 % of the total.Shortspined dog fish, S.mitsukurii, ranged from 150 m to 550 m in depth, mainly between 300-400 m. Trend of catch per unit efforts (CUPUE) using hooked rates expressed by number caught per hundred hooks and unit net length, indicates that they made seasonally vertical migration and go into deep waters during warm seasons while they inhabit shallower depth during cold seasons. However, they were not caught in mid-winter in the coastal waters while they are captured in the seamount near the entrance of Tokyo Bay., suggesting hori … More zontal migration within the bay as well. Segregation by sizes and sexes were also suggested, judging from scarcity of males and small specimens in the catch. Predation by S.mitsukurii on commercially important fishes distributed in the Sagami Bay was also investigated using stomach contents analysis and tooth scars of damaged fishes. As a result, it is concluded that about 8 % of fishes caught by vertical loglines suffered from predation by S.mitsukurii. Age and growth studies were also conducted using annuli marked on second dorsal fin spines. Growth curves were close to those presented by the past studies in offshore area of Choshi while quire different from those in Ogasawara and Seamount of Hancock... Reproductive studies of S.mitsukurii indicate that reproductive strategy is a little different from that obtained from Choshi area. Stomach contents analysis reveals that there seemed to be a little different between regions in Sagami Bay but totally S.mitsukurii are an exclusive picivore as reported by other studies in other regions. Feeding status of seven species was analyzed using stable isotope ratio of nitrogen and carbon. C-N maps indicated that differences between species are rather smaller than differences between habitats. They also differed according to growth stage. Less

本研究在相模湾150 m以下海域共采集到软骨鱼类21种。渔民提供了三种三尖目动物。其中，神奈川县水产研究中心的江之岛丸号（R/V Enoshima-maru）捕捞到的442个样本中，以三栗角鲨（Squalus mitsukurii）的数量最多，占总捕捞量的69%。其他种类的数量占总数量的10%以下，短刺狗舌鱼（S.mitsukurii）的分布深度为150 ~ 550 m，主要分布在300-400 m之间。单位努力渔获量（CUPUE）趋势表明，在温暖季节，它们季节性垂直洄游，进入较深的沃茨，而在寒冷季节，它们栖息在较浅的水域。然而，它们不是在冬季中期在沿海沃茨捕获的，而是在东京湾入口附近的海山捕获的。提示Hori ...更多信息海湾内的萨格勒布人也在迁移。从捕获的雄性和小样本的稀缺性来看，也有人建议按大小和性别进行隔离。利用胃内容物分析和受害鱼牙痕分析等方法，研究了三栗海链霉菌对相模湾重要经济鱼类的捕食作用。因此，它的结论是，约8%的鱼类捕获的垂直loglines遭受捕食S. mitsukurii。年龄和生长的研究也进行了使用环标记的第二背鳍刺。生长曲线与以往铫子近海的研究结果接近，而与小笠原和汉考克海山的研究结果不同。对三叠海蛞蝓的繁殖研究表明，其繁殖策略与铫子地区的繁殖策略略有不同。胃内容物分析显示，相模湾的地区之间似乎有一点不同，但与其他地区的其他研究报告一样，三栗海蜥是唯一的食饵动物。利用氮碳稳定同位素比值分析了7种鱼类的摄食状况。C-N图表明，物种之间的差异比栖息地之间的差异要小得多。它们也因生长阶段而异。少