Age and growth of alfonsino Beryx splendens from the Kanto District, central Japan, based on growth increments on otoliths

ABSTRACT:   Age and growth of alfonsino Beryx splendens (Lowe) were studied using counts of presumed daily incremental growth rings on the transverse section of otoliths of fish collected from the Kanto District, central Japan. Microstructural growth increments were observed from the core to the outermost margin of the broadest of approximately 50 branches formed on the surface of an otolith. Of 98 otoliths examined, 46 were readable. The number of increments and fish lengths ranged from 448 (218 mm fork length [FL]) to 3701 (411 mm FL). The ages of these fish were estimated to be 1 year, 2 months and 10 years, 2 months, respectively, assuming that an increment was formed daily. The von Bertalanffy growth equation combined for males and females was expressed as follows: L _t  = 542 {1 −  exp  [−0.133( t  + 2.00)]}, where L _t is fork length (mm) at yearly age t . The results of the present study were compared with those of other researchers who had studied alfonsino from central Japan.     

日本旋耕机技术特点及操作使用要点

旋耕机作为一种耕整地机械,一次作业可完成耕耘、碎土、整地等多项作业,具有相当高的效率.而且其使用、操作、调整均很简单.因此从1975年开始,旋耕机作为农业机械化的支柱在日本被广泛使用,支撑着日本的农业生产.发展至今,旋耕机已趋于多功能化,不仅仅是耕耘,只要在旋耕机上安装不同的附属设施,就可以进行不同的作业,大大扩展了其作业范围.目前在水田、旱地等均广泛应用着旋耕机.     

韩、日和中国台湾地区处理新农村建设中若干重大关系的比较

借鉴韩国、日本和中国台湾地区新农村建设经验,在新农村建设中,要处理好若干重大关系,主要有政府主导作用和农民主体作用的关系、现代农业建设与环境保护和城市发展的关系、耕地经营规模理想模式和耕地难以集中的现实关系、个体小农经济与合作经济的关系、加强农业投入和确定投入比例重点的关系,以此加速推进社会主义新农村的建设进程。     

Distribution and migration of Japanese common squid, Todarodes pacificus, in the southwestern part of the East (Japan) Sea

Data on squid catches of Korean and Japan, water temperatures at depth of 100 m, and night-visible images of fishing boats collected in the East (Japan) Sea from 1970 to 1999 were analyzed to examine the distribution and migration of the Japanese common squid, Todarodes pacificus, in the southwestern part of the East (Japan) Sea. The main fishing grounds detected from squid catch in each grid (0.5° latitude × 0.5° longitude) by Korean squid fishery and night-visible images provided by the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) were situated in the southwestern part of the East (Japan) Sea. The distribution and migration route was illustrated from squid catch in each grid and DMSP OLS image. In years of high catches, the fishing grounds were situated mainly between Ulleung Island and the eastern coastal waters of Korea, while in years of low catches they were situated between Ulleung Island and the Yamato Bank in the central East (Japan) Sea. The center of fishing activity began moving northward from around the Korea/Tsushima strait to the northern boundary of the Tsushima Warm Current in March, reaching into the Yamato Bank in September, and then returning to the strait by February. The northward and southward migration routes differed; the northward migration route occurred closer to the mainland coast of Korea than the southward migration route did. This work suggests T. pacificus begin their northward migration almost 2 months earlier than previously suggested.     

中日水产品流通体系的比较与启示

日本是世界上最大的水产品消费国和进口国，其水产品流通体系具有很强的代表性、借鉴性，文章通过分析日本水产品流通渠道的形式和特征，结合中国现阶段水产品流通结构的比较，提出中国构建有效水产品流通渠道的建议。     

日本的竹笋罐头生产和进出口情况

本文介绍了日本国内竹笋罐头生产的现状,以及日本的竹笋罐头的进出口情况,近年来竹笋罐头在日本市场上的激烈竞争。     

日本竹产业状况

第二次世界大战以后，日本的竹产业经历了由兴起到兴旺，再转向不振的过程，从中也反映出了竹产业与整个社会经济发展的关系。论文简单地例举了竹产业的部分数据变化，陈述了其中一些原因，这对于我国发展竹产业或许具有一定的参考意义。     

日本野漆树嫁接繁育技术初探

对日本野漆树进行了3年的嫁接试验,探索出日本野漆树引种在我国最佳的嫁接时间和方法,试验结果显示:夏季采用切腹嫁接法,成活率达46%,秋季采用切腹嫁接,成活率达87%,高于日本文献介绍的同期成活率值(30%~40%),可见在我国南方秋季采用切腹嫁接可大大提高日本野漆树嫁接成活率。     

日本木腊引种造林效果及栽培技术

分析了日本木腊引种的生态适应状况和生长效果 ,总结出一套山地造林、栽培管理技术模式     

四川盆地中山地带日本落叶松林分生产力研究

本文根据日本落叶松人工林林分蓄积量、生产力与林龄、立地条件、林分密度等因子的关系,选取21个样地,采用标准地调查、树干解析方法对其人工林的蓄积量、生产力以及与立地条件之间的关系进行了较为系统的研究。研究表明:日本落叶松人工林在四川盆地中山地带生长良好,林分生产力与林分所处立地条件、林分密度、经营管理等密切相关。