Near extinction of a highly fecund fish: the one that nearly got away   总被引：6，自引：0，他引：6  

Yvonne Sadovy  & Wai Lung Cheung 《Fish and Fisheries》2003,4(1):86-99

It is widely assumed that commercial fisheries of highly fecund species are particularly resilient to exploitation, and that, should populations become seriously diminished, economic constraints will force fishing to cease before biological extinction can occur. Indeed, among commercially exploited marine fishes there is not one confirmed global extinction. Here we document, using nonconventional means, a story that not only questions such assumptions but that should also alert us to how little we know about significant fisheries in some parts of the world. Our case study is that of the highly threatened Chinese bahaba, Bahaba taipingensis, a member of the Sciaenidae (the drums or croakers), and an example of a fecund and commercially important group of fishes that appears to be especially vulnerable to fishing. We also demonstrate that the careful use of informal, or traditional, information can provide a powerful, sometimes unique, means of identifying and assessing the status and history of species that might be quietly slipping away before we learn anything about them.  相似文献   

The yellow European eel (Anguilla anguilla L.) may adopt a sedentary lifestyle in inland freshwaters     

P. Laffaille  A. Acou  J. Guillouët 《Ecology of Freshwater Fish》2005,14(2):191-196

Abstract – We analysed the movements of the growing yellow phase using a long-term mark–recapture programme on European eels in a small catchment (the Frémur, France). The results showed that of the yellow eels (>200 mm) recaptured, more than 90% were recaptured at the original marking site over a long period before the silvering metamorphosis and downstream migration. We conclude that yellow European eels >200 mm may adopt a sedentary lifestyle in freshwater area, especially in small catchment.  相似文献   

An assessment of yellow perch, Perca flavescens, stocking contributions in eastern South Dakota lakes     

M. L. BROWN  T. St. SAUVER 《Fisheries Management and Ecology》2002,9(4):225-234

The success and value of yellow perch, Perca flavescens (Mitchill), stocking programmes are largely unknown because of the difficulties in differentiating between naturally recruited and translocated stocks. To determine stocking contributions of yellow perch, fingerlings and adults were collected from natural rearing ponds in south-eastern South Dakota. Prior to stocking, all fish were marked for 6 h in transfer tanks containing 700 mg L⁻¹ oxytetracycline hydrochloride. Six lakes containing yellow perch populations were supplemented at low, medium and high stocking densities of about 25, 135 or 200 fish ha⁻¹, respectively. Yellow perch populations were subsequently sampled with experimental gill nets during late summer; two lakes were resampled with additional gears (electric fishing, trap nets and cloverleaf traps). Yellow perch were processed for routine measurements, and saggital otoliths were removed to determine the origin of the fish. Stock contribution estimates determined from gill-net samples for Island (low), Oak (low), Twin (medium) and Wall (high) lakes were approximately 18, 5, 41, and 38%, respectively. Samples from other gears provided stock contributions of 15 and 10% for Cavour Lake and 41% for Diamond Lake (high density stockings). Although these results showed that supplemental stockings were successful, variability in stock contributions among populations indicates a need for further assessment of variables that may influence the stocking success of yellow perch.  相似文献   

虹鳟肝癌一例   总被引：2，自引：0，他引：2  

刘澧津 《河北渔业》1995,(6):3-4

本文报道了对虹鳟肝脏肿瘤进行的组织学检验情况,认定为恶性肿瘤。病因为饲料中含黄曲霉毒素及鱼体老龄化。  相似文献   

Relationship Between the Conducting Tissue in the First Internode and the Grain filling of Super Large Panicle Rice Restore Line R1126 and Its Derived Combinations     

ZHOU Hong ying  ZHANG Gui lian  XIAO Ying hui  TANG Wen bang  CHEN Li yun 《中国水稻科学》2014,28(4):411

  相似文献   

不同种类真菌多糖对小麦黄矮病的防治效果   总被引：1，自引：0，他引：1  

谢咸升  安德荣 《麦类作物学报》2014,34(4):557-562

为了筛选小麦黄矮病的真菌多糖防治药剂及其适宜浓度,将云芝、灵芝、虫草等13种真菌多糖稀释成0.1、0.5、1.0、2.0g·L-1溶液,以清水为对照,比较分析了叶面喷施真菌多糖对小麦黄矮病的预防和治疗效果,同时对防效好的1.1%云芝葡聚糖(多糖)与常规植物抗病毒药剂的田间防效进行了比较。结果表明,13种真菌多糖对小麦黄矮病的预防作用都显著高于治疗作用,且真菌多糖间和浓度间差异均显著,其中云芝多糖1.0g·L-1、云芝多糖2.0g·L-1、蜜环菌多糖2.0g·L-1、灰树花多糖2.0g·L-1、猪苓多糖2.0g·L-1的预防效果分别为86.88%、86.58%、86.33%、86.04%和85.97%。1.1%云芝葡聚糖800倍液为适宜喷施浓度,其防效64.27%,保产22.70%,说明云芝多糖是一种有前途的新型小麦黄矮病免疫抑制剂。  相似文献   

大连地区大樱桃常见缺素症状及防治对策     

翟立普  刘巍巍 《辽宁农业职业技术学院学报》2014,(3):3-4

大樱桃是多年生木本果树,其根系分布较浅,且养分需求比较集中,常造成某些养分的缺乏。近年来在大连地区大樱桃种植区走访调查发现,钾、锰、镁、硼、铁等养分的缺素现象比较多,因此针对大樱桃以上缺素症状的识别和采取相应的防治对策是很有必要的,同时针对樱桃缺素发生的原因进行了深入的分析,以便于系统的对樱桃缺素进行综合防治。  相似文献   

大类培养模式下《食品工艺学》理论教学改革探索     

徐书景  鞠建松  王会然 《安徽农业科学》2014,(12):3772-3773,3776

结合该校实际与自己的教学经验,依托《食品工艺学》从教学内容、教学方法和考核方式3个方面进行了教学改革探索,以期为同类应用性课程的教学改革提供参考.  相似文献   

甘蓝型油菜无花瓣黄子品系选育     

王俊生  阮先乐  范小芳  陈龙 《湖北农业科学》2014,53(20):4805-4808

为选育甘蓝型无花瓣黄子高油油菜(Brassica napus L.)品种,以显性黄子油菜品系06H440为母本,与自育黑子无花瓣品系AP1进行杂交、回交和连续多代自交,不同回交世代群体隔离种植,以无花瓣和黄子性状为选择标记,采用单株选择和混合选择相结合,品质筛选和抗病鉴定相结合,选育出一系列甘蓝型无花瓣黄子油菜品系.这些品系表现出完全无花瓣、黄色种皮、品质符合低芥酸和低硫甙指标、舍油量高、抗菌核病能力较强及可作为亲本配制高产高油杂交油菜品种等多项优良性状.  相似文献   

黄河三角洲地区新农村建设中的生态环境问题及对策研究     

许经伟  潘莹 《黑龙江农业科学》2014,(3):123-126

随着新农村建设进程的加快,农村生态环境问题日渐凸显。为有效解决农村生态环境问题,选取黄河三角洲地区核心区域为主要研究对象,对新农村建设中的生态环境问题进行了分析,并提出了相应的解决对策,即加强环保宣传、制定新农村建设规划、健全政府工作机制、优化农村产业结构及建立法制保障等。  相似文献