【摘要】 在带鱼耳石横切片上,可以较清楚地看到暗窄带与明亮宽带交替排列所构成的生长年带。春季出生者自当年11月、秋季出生者自12月开始出现窄带,但耳石轮纹的主要形成期均在1—2月份。第一轮径的观测值最小为0.363mm,最大为1.254mm,其相应的鱼体长度为62和261mm。依r₁的大小,东海北部带鱼种群可划分为早生群（r₁≥0.72mm）和晚生群（r₁<0.72mm）。轮纹数相同者归属同一世代。更多还原

【Abstract】 The present paper deals with ageing of hairtails, Trichiurus haumela, based on the transverse section of the otolith. The main materials examined were 3793 specimens collected in the northern East China Sea during the period from May 1977 to June 1978, and the other eleven samples used for comparative study were taken from the continental shelf between the South China Sea and southern East China Sea as well as the Bohai and the Huanghai Seas in recent years. The analytical results are summarized as follows:1.The rather thin transverse section of the otolith is more useful in determining the age and measuring the size than the plate section. It is relatively clear that the borders between the opaque layers and the transparent ones were determined as the rings.2.Monthly observation on the marginal structure of the otolith and calculating the terminal index of each ring group carried out over a period of one year confirmed that the rings on the otolith were formed annually.It is therefore suggested that the opaque zone may be formed during the period from December- to April, mostly in January and February.3.The rhythym of the seasonal growth of the present species has been deduced from analyzing the otoliths growth periodically, which shows that growth of the fish body was very slow during the winter, but remarkably fast during the other seasons of the year.4.It was confirmed that the first rings were produced in the winter of the following year after hatching in spring or summer, or autumn. The fish lengths at the time of ring formation for most individuals of spring-born group were about 200 mm, and about 120 mm or 160 mm for more individuals of autumn or summer-born group. The first annual ring on the otoliths of the spring-born young fish could be formed after tenth month, and for autumn or summer ones was about six or eight month.5.The first annual ring radius is a minimum of 0.363 mm and a maximum of 1.254 mm and its calculated values of body length are 62 mm to 261 mm for all specimens. Hence the radius of the first ring (rt) in the later-born group are smaller than that of the earlier-born group. Thus, by the size of the first ring radius, the population of northern East China Sea are divided into two groups of the earlier-born (n^0.72 mm) and the later-born (r1<0.72mm). The statistical results of ring radius and calculated body length separated by the different season born groups as well as mixed group (including 1% autumn-born group) are shown in Table 1.6.Based on the comparative analysis of otoliths collected from different fishing areas in the coastal waters of China, the investigator found out their morphological characters and the structure of rings are nearly the same. Thus, the technological standard used for observing the otolith rings are generally suitable for determining the age of all population of this species.更多还原