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71.
72.
Knowledge of population distribution and movement is crucial for the conservation and management of shark species occurring in coastal waters. From 1984 to 2009, 641 scalloped hammerheads Sphyrna lewini, 1 342 smooth hammerheads Sphyrna zygaena and 1 352 unspecified hammerheads Sphyrna spp. were tagged and released along the east coast of South Africa, with recapture rates of 1.9%, 1.5%, and 0.7% respectively. Maximum and average distance moved was 629 km and 147.8 km (95% CI = 33.0–262.7 km) for S. lewini and 384 km and 141.8 km (95% CI = 99.1–184.5 km) for S. Zygaena respectively. The majority of sharks (68% S. lewini, 74.1% S. zygaena and 33.5% Spyrna spp.) were tagged in the Transkei region, with the largest number tagged in Port St Johns. Across regions, most tagged sharks were >50–100 cm precaudal length (PCL), except in Transkei where more sharks >100–150 cm PCL were tagged. In the Western Cape, Southern Cape and Eastern Cape, few sharks were tagged during the autumn/winter months, whereas in KwaZulu-Natal and Transkei sharks were tagged throughout the year. Large-scale directional movements observed may have been migrations in response to seasonal sea surface temperature changes. We identify coastal locations in Transkei that are of importance to juvenile and subadult hammerhead populations year-round.  相似文献   
73.
Eimeria anguillae Léger & Hollande, 1922 (Sporozoa: Coccidia) is recorded from Anguilla australis Richardson, 1848 and A. dieffenbachii Gray, 1842 introduced as elvers into a New Zealand eel farm. The parasite is identified by the hexagonal cross section of the sporocysts, dimensions, and lack of asexual and early sexual stages in the mucosal and submucosal tissues. Discrepancies in previously published details of the micropyle and sporocyst vestigal body are attributed to the limitations of earlier microscopes.

In heavy infections the mucosa and submucosa are partially or totally destroyed, and both oocysts and sporocysts are passed out with necrotic tissue.  相似文献   
74.
Tag reporting rate is an important parameter required for estimating fishing and natural mortality in fished populations. It is an extremely difficult parameter to estimate and can vary both during the fishing season and between fishing years. Improving tag reporting rates has been identified as a cost‐effective way of improving precision in fishing and natural mortality estimates derived from tagging data. In this study we evaluated the use of passive integrated transponder (PIT) tags to improve tag reporting rates in a lobster (Jasus edwardsii) trap fishery. To minimise the risk of PIT tag ingestion by consumers, we tested insertion of the PIT tag into the base of the antennae, the base of the walking leg, and the base of the telson. The base of the antennae proved to be the best option for lobster health although impacts were observed at all tag insertion sites. We further developed and tested a hybrid tag that combined a conventional external T‐bar tag with a PIT tag embedded within the shaft. PIT tag scanners were positioned in bottlenecks in the capture process so that all lobsters retained on board the vessel were passed through a scanner. Thus, the tag reporting rate was expected to be 100% for the subsample of the fleet fitted with scanners when scanners were operational. Scanner malfunction was a major issue and further engineering solutions are required to ensure that scanners are reliable when working in harsh marine conditions such as on‐board fishing vessels. Advantages of the hybrid tag are: the ability to be detected by both automatic detectors and fishers; known tag‐induced mortality and tag loss rates from previous research; and PIT tagging without risk of human ingestion.  相似文献   
75.
分析了当前海洋测绘档案管理中存在的主要问题,阐述了无线射频识别技术(radio frequency identification,RFID)技术在海洋测绘档案管理应用方面的技术优势和特点,设计一套基于RFID技术的海洋测绘档案智能化管理系统,并就该系统的功能模块架构进行阐述,以期在海洋测绘档案信息化、智能化管理方面做出改善。  相似文献   
76.
建鲤与黄河鲤的RAPD分子标记及其杂交优势的遗传分析   总被引:3,自引:0,他引:3  
利用RAPD技术对建鲤、黄河鲤及其杂交子代进行了遗传分析,筛选的33个引物共扩增出155条带,其中多态性片段为105条,片段S18-1600、S472-300具有种的特异性,可作为鉴别建鲤与黄河鲤的分子遗传标记。建鲤、黄河鲤及其正、反交子代群体内的遗传相似系数分别为0.8240、0.7921、0.7920、0.8569,黄河鲤与正交F1具有较高的遗传变异水平,反交F1变异最小。正交F1、反交F1与亲本(建鲤、黄河鲤)的遗传距离分别为0.2233、0.2436、0.1749、0.2026,说明子代均继承了较多的建鲤的遗传物质。分析了子代与亲本的RAPD标记类型以及各类型的条带数。应用PIT标记系统测定了子代的杂种优势并探讨了优势产生的遗传机理。  相似文献   
77.
以海带(Laminaria ja ponica Aresch)为重点,综述了海带属褐藻生物学研究成就,介绍了海带属褐藻遗传育种技术、育苗技术和分子生物学研究进展。海带属褐藻生物学研究基础好,种质资源丰富,经济、生态价值高,是进行大型海藻遗传学和基因组学研究的理想材料。  相似文献   
78.
叙述了传统食堂售饭系统的不足,介绍了CAN总线与非接触式IC卡技术的特点和优势,并对以这两种技术为基础的新型食堂售饭系统窗口机的软硬件设计原理进行了较详细的分析。窗口机硬件系统主要由CAN总线通信接口、IC卡读写器、键盘、显示和存储器等功能模块组成,软件系统主要由窗口机初始化模块、窗口机监控模块、窗口机按键处理模块等组成。论文在对窗口机原理进行分析的同时,也对设计中遇到的关键问题进行了讨论,对于今后食堂售饭系统的设计提供了一个新的思路。  相似文献   
79.
ABSTRACT

The oceanic spawning migration of female Anguilla dieffenbachii eels was previously studied using pop-up satellite transmitting tags (PSAT). The swimming depths and experienced-temperature data of 3 eels released in May 2006 were re-examined in relation to water temperature data, and also lunar cycle and regional hydrography as these latter aspects were not considered in the original study. Eel 2 and Eel 3 initially experienced lower water temperature above 600?m, suggesting they remained south of the subtropical-convergence front longer than Eel 1. Their experienced nighttime minimum depths showed linear relationships with the lunar cycle, because they swam shallower during new moon than during full moon. The eels experienced narrow deep-day temperature ranges at a wide range of depths compared to experiencing narrow shallow-night depth ranges where temperatures varied more widely, indicating that several different factors determine their day and night depth ranges.  相似文献   
80.
韩军  颜龙 《地震工程学报》2015,37(3):896-900
动物异常是地震宏观测报的一个重要手段,本研究旨在帮助科研人员建立起长期的动物生活习性信息管理系统,方便其对动物生活习性信息的收集和研究。通过为每一只宏观观测动物配置ID卡,利用LabVIEW提供的串口配置函数和LabSQL工具包,上位机在Access数据库中调取每个ID所对应的动物日常生活习性信息,实现对动物信息表的查看、特定动物信息查询以及动物信息录入等功能。为科研人员掌握宏观观测动物生活习性,辨别动物震兆异常行为提供依据。  相似文献   
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