漓江中游近岸水域仔稚鱼物种组成及其与生境的关系

Species composition and habitats of larval and juvenile fish in the shoreline waters of the middle reaches of Lijiang river

2014年5月、6月和7月对漓江中游近岸水域4种不同生境组合(A-复合河岸+卵石底质+有水生植物、B-天然河岸+沙底质+有水生植物、C-人工护岸+卵石底质+有水生植物、D-人工护岸+卵石底质+无水生植物)的仔稚鱼聚群进行了调查,共采集仔稚鱼样本5 416尾,经鉴定为11种,隶属于3目5科10属.4种生境间的β多样性Cody指数测度矩显示,生境A、B与生境D物种组成差异较大,生境A与生境B差异最小.对4种生境仔稚鱼物种丰富度与丰度进一步做单因素方差分析(one-way ANOVA)和LSD多重比较,结果表明:有水生植物的生境仔稚鱼物种丰富度明显高于无水生植物的生境(P<0.05),有水生植物的天然河岸生境中仔稚鱼丰度大于无水生植物的人工护岸生境仔稚鱼丰度(P<0.05),而底质类型对仔稚鱼丰富度和丰度影响不显著(P>0.05).

Larval and juvenile fish samples were collected from shoreline and shallow waters of the middle reaches of Lijiang River in May,June,and July of 2014. Four habitat types（ A： compound bank with grait and aquatic plants,B： natural bank with sand and aquatic plants,C： constructed bank with grait and aquatic plants,and D： constructed bank and graits without aquatic plants） were investigated. We collected a total of 5416 individuals of 11 species,belonging to 3 genera,5families,and 10 orders. β-Cody diversity index measurement matrix demonstrated that types A and B and type D are significantly different in species richness level. One-way ANOVA and LSD analysis showed that the species richness and abundance of larval and juvenile fish were significantly higher in types A and B than type D,and were similar in types A and B. Aquatic vegetation had a significant impact on species richness and bank type combined with aquatic plant had a significant impact on larval and juvenile fish abundance. However,sediment had no significant impact on abundance. In a word,restoration of riparian and aquatic vegetation is crucial to the maintenance of species richness and abundance of larval and juvenile fish.