Using multi-mesh gillnets and trawls, the fish communities in Dianshan Lake at 6 stations from Oct. 2009 to Jul. 2010 were investigated seasonally to reveal the biodiversity and its spatial and temporal distribution p...Using multi-mesh gillnets and trawls, the fish communities in Dianshan Lake at 6 stations from Oct. 2009 to Jul. 2010 were investigated seasonally to reveal the biodiversity and its spatial and temporal distribution patterns. The long-term changes in their structural characteristics were then analyzed to identify the main infl uencing factors and several measures for lake restoration were put forward. Thirty six species, belonging to 9 family and 30 genera, were collected, amongst which, the order Cypriniformes accounted for 61.1% of the total species number. In terms of importance value, Cypriniformes was the predominant group, Coilia nasus the dominant species, while Cyprinus carpio and Rhinogobius giurinus were the subdominant taxa. The community types did not differ among stations, but between seasons. There were no significant differences between seasons and among stations in species diversity, but richness differed both spatially and seasonally. Along with the process of eutrophication and the drastic reduction of the area colonized by macrophytes from 1959 to 2009–2010, the fish diversity declined markedly, and species numbers of herbivores and piscivores declined proportionately more than those of invertivores, omnivores, and planktivores. The decline of potamophilus and river-lake migratory fish was more marked than those of sedentary, river-sea migratory, and estuarine fishes. Eutrophication concomitant with sharp reduction of macrophyte area and overfishing may be the main reasons for the decline in fish diversity in Dianshan Lake.展开更多
Fish diversity in different habitats and their preference for a particular habitat was studied in a freshwater stream Hinval in Western Himalayas of Garhwal region. A total of 7 fish species belonging to 2 orders were...Fish diversity in different habitats and their preference for a particular habitat was studied in a freshwater stream Hinval in Western Himalayas of Garhwal region. A total of 7 fish species belonging to 2 orders were recorded. The maximum fish diversity and dominance was reported in the cyprinids. Two species of order Cypriniformes, Tot putitora （Ham.） and Barilius bendelisis （Ham.） were recorded at all the three sites, although they were more abundant at sites I and II. Among the Barilius spp., Barilius bendelisis （Ham.） was the most common at all the study sites, while Barilius barna （Ham.） and Barilius vagra （Ham.） were only found at Ⅰand Ⅱsites. The pool habitat was the most preferred habitat of almost all the species with （＇H＇=0.521-0.594） tbllowed by rapid and riffle habitat respectively.展开更多
基金Supported by the Science and Technology Commission of Shanghai Municipality(Nos.08DZ1203101,08DZ1203102)the Shanghai University Knowledge Service Platform,Shanghai Ocean University Aquatic Animal Breeding Center(No.ZF1206)the Open Project of Key Laboratory of Freshwater Biodiversity Conservation and Utilization,Certificated by Ministry of Agriculture of China
文摘Using multi-mesh gillnets and trawls, the fish communities in Dianshan Lake at 6 stations from Oct. 2009 to Jul. 2010 were investigated seasonally to reveal the biodiversity and its spatial and temporal distribution patterns. The long-term changes in their structural characteristics were then analyzed to identify the main infl uencing factors and several measures for lake restoration were put forward. Thirty six species, belonging to 9 family and 30 genera, were collected, amongst which, the order Cypriniformes accounted for 61.1% of the total species number. In terms of importance value, Cypriniformes was the predominant group, Coilia nasus the dominant species, while Cyprinus carpio and Rhinogobius giurinus were the subdominant taxa. The community types did not differ among stations, but between seasons. There were no significant differences between seasons and among stations in species diversity, but richness differed both spatially and seasonally. Along with the process of eutrophication and the drastic reduction of the area colonized by macrophytes from 1959 to 2009–2010, the fish diversity declined markedly, and species numbers of herbivores and piscivores declined proportionately more than those of invertivores, omnivores, and planktivores. The decline of potamophilus and river-lake migratory fish was more marked than those of sedentary, river-sea migratory, and estuarine fishes. Eutrophication concomitant with sharp reduction of macrophyte area and overfishing may be the main reasons for the decline in fish diversity in Dianshan Lake.
文摘Fish diversity in different habitats and their preference for a particular habitat was studied in a freshwater stream Hinval in Western Himalayas of Garhwal region. A total of 7 fish species belonging to 2 orders were recorded. The maximum fish diversity and dominance was reported in the cyprinids. Two species of order Cypriniformes, Tot putitora （Ham.） and Barilius bendelisis （Ham.） were recorded at all the three sites, although they were more abundant at sites I and II. Among the Barilius spp., Barilius bendelisis （Ham.） was the most common at all the study sites, while Barilius barna （Ham.） and Barilius vagra （Ham.） were only found at Ⅰand Ⅱsites. The pool habitat was the most preferred habitat of almost all the species with （＇H＇=0.521-0.594） tbllowed by rapid and riffle habitat respectively.
