大黄鱼仔稚鱼不同发育阶段矢耳石形态发育和微结构特征

大黄鱼仔稚鱼不同发育阶段矢耳石形态发育和微结构特征刘志远;李圣法;徐献明;张翼;黎雨轩

【摘要】We documented the morphological development and microstructure of the sagittal otolith during the larval and early juvenile stages (between hatch and 78 d after hatch) of large yellow croaker (Larimichthys crocea). We observed daily periodicity in growth increment formation in the sagittal otoliths. The first daily increment was formed 2 days after hatching (dah), corresponding to the time of first feeding. The sagittas were round in shape during the yolk-sac larval and pre-flexion larval stages, subsequently becoming elongated on the long axis during the flexion larval stage. Following this, the sagitta became ellipsoid in shape during the post-flexion larval stage. During the early juvenile stage, the first secondary primordium began to form between 29-39 dah

(32±0.39), corresponding to the timing of metamorphosis from larvae to juvenile. The number of secondary primordium ranged from 5 to 7 in 47-78-day-old juveniles, and the secondary growth zone (SGZ) surrounding the first growth zone (FGZ) formed an "enclosed structure". During this stage, the sagittas were nearly peltate in shape. The radius (R) of the sagitta was significantly and linearly related to standard length (Ls) for all individuals (R =-155.8+39.1 Ls) (n=211, P＜0.001). The growth rates during the larvae stage (ft), calculated based on the width of the daily increment on the sagitta of juveniles, were significantly and linearly related to the time of formation of the first secondary primordium (tsp1) (b =38.6-

161.9tsp1) (n=42, P＜0.01). This suggests that the secondary primordium was formed much earlier and metamorphosis was more rapid in faster growing larvae. In summary, the pattern of early life history growth and development of large yellow croaker can be back-calculated based on sagitta size, morphology, and microstructure. Our results provide a theoretical basis for measuring early growth and development and documenting recruitment of large yellow croaker in the field.%对人工培育大黄鱼(Larimichthys crocea)的生长发育与矢耳石形态及微结构特征进行研究,结果表明:(1)大黄鱼矢耳石上的轮纹是每日形成的,第1日轮在孵化后第2天形成,与其初次摄食相对应.(2)大黄鱼卵黄囊期和前弯曲期仔鱼的耳石形态为圆形,进入弯曲期耳石长轴迅速伸长,在后弯曲期耳石形态变为椭圆形.进入稚鱼期,矢耳石开始形成次生核.随后次生核数量逐渐增加,在孵化后47～78 d的个体中,次生核数量稳定在5～7个,耳石近似盾形.(3)根据耳石日轮宽度推算的大黄鱼稚鱼在其仔鱼期生长率(b)与第1个次生核的形成时间(tspt)之间存在明显的线性关系,表明生长较快的个体形成次生核的时间较早,进入稚鱼期所需的时间更短.以上结论表明,大黄鱼矢耳石可以反演其早期生活史阶段的生长发育特征.

【期刊名称】《中国水产科学》

【年(卷),期】2012(019)005

【总页数】9页(P863-871)

【关键词】大黄鱼;耳石;日轮;次生核;生长率

【作者】刘志远;李圣法;徐献明;张翼;黎雨轩

【作者单位】中国水产科学研究院东海水产研究所,农业部东海与远洋渔业资源开发利用重点实验室,上海200090;上海海洋大学海洋科学学院,上海201306;中国水产科学研究院东海水产研究所,农业部东海与远洋渔业资源开发利用重点实验室,上海200090;江苏省海洋水产研究所,江苏南通226007;中国水产科学研究院东海水产研究所,农业部东海与远洋渔业资源开发利用重点实验室,上海200090;上海海洋大学海洋科学学院,上海201306;中国水产科学研究院东海水产研究所,农业部东海与远洋渔业资源开发利用重点实验室,上海200090

【正文语种】中文

【中图分类】S931

耳石记录了鱼类早期生长发育阶段的生活史事件, 如年龄、生长、发育和种群补充等重要信息[1-3]。大多数鱼类耳石上的轮纹每天形成 1轮,称为日轮[4-6]。第1日轮的形成通常与孵化或初次摄食有关[7], 通过确定耳石日轮的数量和第 1条日轮的形成时间就可以估算个体的日龄[8-10]。大量研究表明, 耳石日轮宽度与个体生长速度密切相关, 因此可以用来分析个体的早期生长状况[7, 11]。耳石上次生核(secondary primordium)的形成通常被认为是仔鱼期向稚鱼期转变的一个重要标志,根据耳石上日轮宽度及次生核的形成时间, 就可以估计个体变态发育的时间及其早期选择性死亡的状况[12-14] 。

大黄鱼(Larimichthys crocea)曾是中国近海重要的经济鱼类, 由于过度捕捞等原因, 大黄鱼资源已严重退化, 目前很难形成鱼汛。虽然近年来的人工增殖放流已取得初步成效[15], 但大黄鱼种群在自然条件下的繁殖时间及其早期仔稚鱼的生长发育状况还不清楚。因此本研究通过对人工培育的大黄鱼仔稚鱼的矢耳石形态及微结构进行观察, 分析其耳石轮纹沉积率、耳石形态和微结构特征与个体生长发育的对应关