西北太平洋秋刀鱼耳石透明带的初步研究

On statolith hyaline zones of Pacific saury Cololabis saira in the Northwest Pacific

根据2014年我国秋刀鱼捕捞船在西北太平洋采集的秋刀鱼（Cololabis saira）样本,提取1 062个耳石进行拍照处理,并根据耳石透明带特征对其进行划分,运用统计学方法研究耳石类型及与肉体长组的关系,分析各月份耳石类型变化。研究发现,83%小型鱼（Kn L≤240 mm）和71%中型鱼（240 mm314 mm）耳石类型Ⅱ、类型Ⅲ占优。肉体长在280 mm以下的类型Ⅰ耳石比例较大,耳石没有形成透明带,随着Kn L的增加,类型Ⅱ和类型Ⅲ在肉体长组的比例增加。耳石透明带最早在202 mm时开始形成,秋刀鱼耳石第1条透明带主要在260~280 mm之间形成,以中型鱼为主;秋刀鱼耳石第2条透明带主要在290~310 mm之间形成,以大型鱼为主。雌性和雄性秋刀鱼耳石在各耳石类型下无显著差别（P=0.064〉0.05）。耳石类型Ⅰ比例在月份间变化大,在10月和11月份耳石类型Ⅰ比例占优,分别为44.1%和36.4%,多为小型和中型鱼,6月和7月份耳石类型Ⅱ和类型Ⅲ比例大约为40%,多数为大型和特大型鱼,表明大型鱼比小型和中型鱼早到达索饵场进行索饵。

Based on samples collected by Chinese saury fishery fleets from the Northwest Pacific in 2014,1 062 specimens were extracted and measured,and their statolith types were divided according to hyaline zones of statolith. The paper is to study hyaline zones of statolith and its relationship with knob length group using statistics,and to analyze the variation of statolith types in different months. Results showed that 83% of small-sized fish and 71% of medium-sized fish（ Kn L ≤280 mm） exhibited type Ⅰ,and in large-sized fish（ 280 Kn L≤314 mm） and very large-sized fish（ Kn L 314 mm） the dominant was in type Ⅱ and type Ⅲ,type Ⅰ of C. saira（ Kn L ≤280 mm） had higher percentage,its statolith did not form hyaline zones,the proportion of type Ⅱ and type Ⅲ increased in each group with the increasing of Kn L. Led statolith hyaline zones began to form in 202 mm,the first hyaline zones of C. saira formed between 260- 280 mm,and medium-sized fish was dominant,the second hyaline zones of C. saira formed between 290- 310 mm,and large-sized fish was dominant. Statolith type proportion of male and female Pacific saury had no difference（ P = 0. 064 0. 05）. Variation of type Ⅰ statolith in different months is obvious. Percentage of type Ⅰis dominant in October and November,and is 44. 1% and 36. 4% respectively,moreover,it is mostly small and medium-sized fish,percentage of type Ⅱ and type Ⅲ is 40% approximately in June and July,and is mostly large-sized and very larged fish,suggesting that large-sized fish arrives in feeding ground earlier than small and medium-sized fish.