罗源湾鱼卵仔稚鱼的分布特征

Distribution Characteristics of the Ichthyoplankton of the Luo Yuan Bay,Fujian

共采获鱼卵 24,988粒、仔稚鱼 9,572尾,鉴定了鱼卵、仔稚鱼 78种,其中鱼卵 43种,仔稚鱼 49种,各有优势种 9种。春、夏季鱼卵仔稚鱼数量较多,6月为鱼卵的高峰期,仔稚鱼在5月,鱼卵集中分布在8、7和2站而4和5站为仔稚鱼的聚集区。鱼卵、仔稚鱼全年最高采获量分别为8站和4站。鱼卵种类数5月最多,仔稚鱼为9月。鱼卵种类数以1和8站最高,仔稚鱼为4站。运用群集结构相似值和相异值,绘制系统聚类图,将鱼卵分为4个群集区,仔稚鱼分为3个群集区。文中首次引入五个群集结构的特征指数和五个聚集强度指标对鱼卵、仔稚鱼群集进行研究,结果表明,湾内重点保护区应是8和4站,春、夏两季是鱼类资源繁殖保护期。

The present paper determines 78 species of ichthyoplankton which include 49 species of larvae and juvenil as well as 43 species of eggs from the Luoyuan Bay. Among the samples there are nine dominant species of eggs and larvae respectively,In the collecting year, the max quantity of eggs is the 8th sation (17,447 eggs/year) and that of larvae in the 4th station (6,539 larvae/year).On the other hand the max amount of species number of egg is in the 1st and 8th stations.that of larvae in the 4th stations.The species number of eggs are most in May and larvae are most in September. In the Bay ,the eggs is concentrate in 8th,7th and 2nd stations but the larvae is in the 4th and 5th stations the quantity of eggs and larvae is abundance in Spring and Summer.According to the calculation of the Bray-Curtis similarity(s) and dissimilarity(c).the egg can be divided basically into four aggregation zones and that of larvae can be divided into three.This paper first tried to recommend five characteristis index of aggregation structure and five assemblage density to study ichthyoplankton aggregation.The eggs aggregation structure was stablest and most complecated during spring and Summer is second to the Spring but that of the larvae is fairly stable in autumn and Winter.The eggs aggregation structure is more stable and complicated than that of larvae. The eggs assemblege density is highest in the aggregation region IV and that of larvae is highest in the aggregation region C.The max biomass of eggs is distributed in the southeast of the Bay .namely aggregation Ⅳ and Ⅲ,and that of the larvae in the northwest of the Bay ,,namely,aggregation C and B.As a result of our analysis.the 8th and 4th stations should become major regions of protection and Spring and Summer should be the fish resource reproduction periods.