碧流河水库鱼类寄生虫调查     

何幽峰  康淑梅 《大连水产学院学报》1988,(Z1)

本文报导了1984—1986年碧流河水库鱼类寄生虫调查.共检查、解剖鱼类49种,计846尾。查见寄生虫13个类群.计51种.对寄生虫在鱼体上的寄生部位、感染率、感染强度作了记录.根据调查和鱼种放养情况.提出了鱼病预防建议.  相似文献   

呼市郊区鱼类寄生虫种类和感染情况     

郭媛华  刘珍莲  呼和巴特尔 《内蒙古农业大学学报(自然科学版)》1994,(1)

近年来，鱼类寄生虫病在呼和浩特市地区经常发生。为此，作者于１９９２年３～１０月对呼市郊区主要经济鱼类进行了调查，共得到１６种鱼类寄生虫，隶属于８纲、１２目、１２科、１２属。同时，对鱼类寄生虫的感染情况也进行了研究。  相似文献   

贪食迈阿密虫(M.avidus)对4种海水养殖鱼类组织匀浆液的趋化性     

林能锋  陈立志  曾红 《福建畜牧兽医》2021,(2):11-13

通过对贪食迈阿密虫(M.avidus)对4种养殖鱼类组织匀浆液的趋化特性进行研究,以探讨贪食迈阿虫对养殖鱼类的侵染特点.试验结果显示,贪食迈阿密虫对大黄鱼、大菱鲆、黄姑鱼、鲈鱼的眼、脑、脑脊液匀浆液有强烈的趋化效果(P＜0.01),对皮肤黏液、鳃、肝、肌肉、肾组织匀浆液的趋化性较弱(P＞0.05);对不同鱼类组织匀浆液...  相似文献   

中国的冷水性鱼类及其开发利用     

张觉民 《水产学杂志》1990,3(1):1-20

本文系统的阐述了中国冷水性鱼类资源及其分布状况,中国冷水性水域及冷水性鱼类的开发价值。同时概述了中国冷水性鱼类资源开发利用的现状以及存在的问题,并对今后冷水性渔业提出了规划。  相似文献   

新疆土著鱼类的数值分类     

田永胜  潘育英  王国英 《新疆农业大学学报》1994,(1)

本文采用鱼类的３４个可数量化性状，借助微机，利用主成分分析法对新疆５１种土著鱼类进行数值分类，其结果可将新疆土著鱼明显地划分为：条鳅属鱼类，臀鳞鱼亚科鱼类，雅罗鱼亚科鱼类３个主要的群体。  相似文献   

松花江哈段主要排污口污水对设置网箱中鱼类成活率的影响     

战培荣  陈惠等 《水产学杂志》1996,9(2):44-46

用设置网箱的方式，监测松花江哈段主要排污口水质对鱼类成活率的影响。结果表明：未经处理的污水排入江中，明显的影响鱼类的生长，并且产生致死效应，城市污水集中处理十分重要。  相似文献   

Metapopulation analysis indicates native and non‐native fishes respond differently to effects of wildfire on desert streams          下载免费PDF全文

James E. Whitney  Keith B. Gido  Tyler J. Pilger  David L. Propst  Thomas F. Turner 《Ecology of Freshwater Fish》2016,25(3):376-392

Ash flows and flooding associated with wildfires represent important but understudied sources of disturbance for fish populations. Knowledge concerning these disturbances is especially limited for larger streams where warm water species dominate. Fire‐related disturbances have been hypothesised to differentially affect native and non‐native fishes, although this hypothesis has only been tested for salmonids. The objective of our research was to contrast effects of uncharacteristically large wildfires followed by flooding on metapopulations of native and non‐native fishes in the Gila River of southwest New Mexico. Probabilities of occupancy, colonisation and local extinction of fishes were calculated across sites before and during disturbance and were also measured across a broader spatial scale during disturbance to identify potential refuge locations. Occupancy was higher for native fishes than non‐natives, but multiple wildfire and flood events increased extinction probabilities of native species. Responses of non‐native species to wildfires were mixed; extinction of non‐native salmonids increased during disturbance, while extinction of several warm water species remained unchanged or decreased. Several undisturbed sites were poor refugia for natives as they were impacted by non‐native piscivores, dewatering, and fragmentation. However, despite exposure to multiple disturbances, sites located in large tributary and valley reaches were consistently occupied by native species, suggesting these habitats provided refugia. We suggest that management actions (forest thinning; prescribed burning) that restore a more natural disturbance regime of small and less severe fires coupled with habitat remediation activities (non‐native removal; decreased water withdrawal; improved connectivity) might diminish extinction risk for native fishes exposed to wildfire disturbance.  相似文献   

Quantifying ichthyofaunal zonation and species richness along a 2800‐km reach of the Rio Chama and Rio Grande (USA)     

Daniel J. McGarvey 《Ecology of Freshwater Fish》2011,20(2):231-242

Abstract – Ichthyofaunal zonation occurs when lotic fishes are partitioned into distinct assemblages, usually in response to longitudinally distributed habitats. Several studies have documented zonation within the Rio Grande, but this is the first to quantitatively test the zonation hypothesis along a continuous 2800‐km river profile, extending from the Rio Chama headwaters to the Gulf of Mexico. Using a large, multi‐source dataset, I detected three ichthyofaunal zones: a high gradient (～1.5%) ‘upper’ zone, a moderate gradient (～0.2%) ‘middle’ zone and a low gradient (<0.1%) ‘lower’ zone. Species richness was lowest in the upper zone and highest in the lower zone, and all zones contained large numbers of nonnative species. However, species richness did not accumulate in a consistent, downstream manner. Instead, it tracked local‐scale changes in mean annual discharge. This demonstrates the strong effect of river regulation and irrigation withdraws on fish diversity in the Rio Grande.  相似文献   

The Palaeozoic, Mesozoic and Early Cenozoic fishes of Africa   总被引：2，自引：0，他引：2  

A.M. Murray 《Fish and Fisheries》2000,1(2):111-145

Africa has provided many fossil fishes from sediments laid down over a 400 million year period. The large array of fossil fishes come from diverse localities throughout the continent, representing a variety of environments. The marine fossil fishes of Africa have not been reviewed as a whole, while the freshwater Cenozoic fishes of Africa were last reviewed over 25 years ago. Since that time, many new finds have increased our knowledge of the history of African fishes. This paper summarizes the known fish fossils, excluding otoliths, from marine and freshwater deposits throughout Africa from the Palaeozoic, Mesozoic and first part of the Cenozoic (Palaeogene). Much new work is ongoing, in areas such as Mali and South Africa, from which more information on the ichthyofaunas should come to light. New information presented here includes the Eocene site of Mahenge, Tanzania, from which have come the oldest known members of the family Cichlidae.  相似文献   

太湖主要鱼类食物组成   总被引：5，自引：0，他引：5  

刘恩生 《水产学报》2008,32(3):395-401

根据2004年9-12月和2005年4月的调查,研究了太湖8种鱼的食物组成.结果表明:优势种鲚主要摄食枝角类、占食物个数比例89.77%±13.69%;太湖新银鱼主要摄食桡足类、占个数比例70.11%±10.57%;鲢、鳙主要摄食微囊藻、占食物体积比例90%以上;鲤食物中水生植物约占体积比例70%;鲫主要摄食微囊藻、占体积比例93.99%±3.34%;翘嘴红鲌、蒙古红鲌主要摄食鲚和小型鱼类.分析认为,随着太湖富营养化程度不断加重,以蓝藻为主的浮游植物食性鱼产力在快速增加,但实际渔获量以浮游动物食性鱼类为主.如2003年浮游植物食性鱼产力为10234t、占总鱼产力37.0%.而2004年实际渔获量中浮游动物食性鱼类占80%-90%,浮游植物食性鱼类渔获量仅3637.7t、占10.9%.因此,太湖现有鱼类群落组成和实际饵料构成是不吻合的.不仅如此,浮游动物食性鱼类数量的快速增加对浮游动物形成了巨大牧食压力,这更利于藻类繁殖.太湖鲫几乎完全以微囊藻为食物,可能对蓝藻暴发有抑制作用,应重新评价其对环境的影响.  相似文献