长江安庆段仔稚鱼群落特征调查研究

安庆江段是长江下游重要渔业资源水域之一, 为了解该江段仔稚鱼群落特征及与环境因子的关系, 于2016年4月17日至8月15日对安庆江段仔稚鱼进行了逐日调查。结果显示: 研究共采集仔稚鱼个体92160尾, 鉴定90457尾, 隶属于7目11科49种, 其中鲤科(Cyprinidae)种类数居第一, 32种, 尾数占比为90.16%; 鰕虎鱼科(Gobiidae)居第二, 3种, 尾数占比为5.71%。在生态类型及产卵方式上, 淡水定居性鱼类和产漂流性卵鱼类数量占比最大, 分别为87.57%和88.30%。贝氏?(Hemiculter bleekeri)是该江段第一优势种, 数量占比44.53%, 其余优势种为?(Hemiculter leucisculus, 占比14.21%)、银鲴(Xenocypris argentea, 占比8.11%)、子陵吻鰕虎(Rhinogobius giurinus, 占比5.60%)、飘鱼(Pseudolaubuca sinensis, 占比4.75%)、似鳊(Pseudobrama simoni, 占比4.13%)、寡鳞飘鱼(Pseudolaubuca engraulis, 占比4.50%)、鳊(Parabramis pekinensis, 占比2.63%)、刀鲚(Coilia nasus, 占比1.89%)、鲢(Hypophthalmichthys molitrix, 占比1.57%)。仔稚鱼丰度出现4次明显的高峰时期, 第一次在5月1日, 后面三次集中出现在6月中下旬, 分别为1127.00、1608.44、1568.35 和1202.94 ind./100 m3。通过冗余分析(RDA)表明, 影响安庆江段仔稚鱼丰度的主要环境因子为水流量、水位、透明度(P<0.05), 大多数仔稚鱼丰度与水流量、水位呈现负相关, 与透明度呈现正相关, 可能与该年份过高的水流量、水位有关。研究表明, 安庆江段的仔稚鱼种类较丰富, 但主要以小型鱼类为主, 且经济性仔稚鱼类占比小。研究初步探明了安庆江段的仔稚鱼资源状况, 其结果为安庆鱼类早期资源进一步研究提供基础资料, 同时也为渔业资源保护策略制定提供科学依据。

THE COMMUNITY CHARACTERISTICS OF LARVAE AND JUVENILE FISH IN THE ANQING SECTION OF THE YANGTZE RIVER

Anqing section is one of the important fishery resources waters in the lower reaches of the Yangtze River. To understand assemblage characteristics of larvae and juveniles fish and their correlation with environmental factors, the early fish resources in Anqing section were investigated day by day from April 17 to August 15, 2016. The results revealed that a total of 92160 larvae or juveniles were captured, and 90457 were identified, belonging to 7 orders, 13 families and 49 species, while Cyprinidae was the largest family including 32 species, accounting for 90.16% of the total number of tails; Gobiidae was the second largest family including 3 species, accounting for 5.71% of the total number of tails. As for ecological type and spawning type, fishery residents fishes and fishes with pelagic eggs accounted for the largest proportions of 87.57% and 88.30%, respectively. Hemiculter bleekeri (44.53%) was the largest dominant species in this section and the other dominant species were Hemiculter leucisculus (14.21%), Xenocypris argentea (8.11%), Rhinogobius giurinus (5.60%), Pseudolaubuca sinensis (4.75%), Pseudobrama simoni (4.13%), Pseudolaubuca engraulis (4.50%), Parabramis pekinensis (2.63%), Coilia nasus (1.89%) and Hypophthalmichthys molitrix (1.57%). Larvae or juveniles abundances have four obvious outbreak period with the first period on the 1st May and the other three in the mid to late June, which were 1127.00, 1608.44, 1568.44, 1202.94 ind./100 m3, respectively. Redundancy analysis (RDA) revealed that the main environmental factors affecting the abundance of larval and juvenile fish in Anqing river section are water flow, water level and transparency (P<0.05). The abundance of most larval and juvenile fish were negatively correlated with water flow and water level, and positively correlated with transparency, which may explain by the excessive water flow and water level in that year. This study demonstrated that Anqing section was abundant of diverse species of early fish resources which mainly consisted of small fish, and the proportion of economic juvenile fish is small. These results provide basic information for the formulation of protection policy on Anqing fishery resources with scientific reference.