闽南、台湾浅滩渔场二长棘鲷的生长特性

根据1998年7月至2000年6月闽南、台湾浅滩渔场二长棘鲷的生物学资料,研究其年龄组成和生长特性.二长棘鲷捕捞群体由0～Ⅵ龄组7个世代组成,以0龄组为主,Ⅰ龄组次之,平均年龄为0.71龄.应用vonBertalanffy生长方程拟合的生长参数L∞=244.56mm,K=0.2313,t0=-1.1817,体重的生长拐点为3.71龄.与上世纪80年代初相比,二长棘鲷群体结构已发生很大的变化,个体早熟化,生长速度加快,捕捞群体小型化、低龄化,二长棘鲷幼鱼损害情况严重,资源处于过度利用状态.根据渔获组成、资源现状及生长特性,建议加强对二长棘鲷幼鱼的保护和管理,合理利用其资源.

Growth characteristics of golden-skin porgy,Parargyrops edita,in the south Fujian and Taiwan bank fishing ground

According to the biological data published, the age composit ion and growth characteristics of crimson tai ( Parargyrops edita Tanaka) grown in the south Fujian and Taiwan bank fishing ground in the period of July 1998 through June 2000 were studied. It was found that the catch consisted of 7 year-classes from 0 to 6 age in which 0 age was dominant. The average age was 0. 71, being smaller than 1. 08 in 1976 and 0. 99 in 1994. On the basis of their actual length and weight of each age class, the relative growth rate, instaneous growth rate and growth target were computed. It could be seen that crimson tai grew quickly prior to 2 age, stably in the stage of 2 to 4 age, and doated after 4 age. The parameters of von Bertalanffy.. s growth equation were: L .. = 244. 56 mm, K = 0. 2313 and t 0= - 1. 1817. The infexion point on the body weight growth curve of stock was 3. 71, being lower than 5. 38 in the early 1980s. As compared with the population structure of f ish, a tangible variation occurred, in which the adult s were early matured and their growth speed increased, while the individuals of catch stock were smaller and in low-aged size. The fork length of maturing female individuals was 117mm seen for the f irst time and the individuals of the same generation all possibly matured which were born before one year. In recent years, the yield of crimson tai in the area of the south Fujian and Taiwan bank fishing ground possibly remained in high level, the main reason of which was overf ishing of immaturing population. Now the resources of crimson tai seems in a state of overexplo itation with high intensive utilization. Therefore, based on the catch composition, stock status and growth characterist ics, it is suggested that the young stage of crimson tai should be well protected and managed as well as reasonably utilized.