东南太平洋智利竹荚鱼矢耳石的形态特征分析

Study on sagitta morphology of Chilean jack mackerel (Trachurus murphyi) in the southeast Pacific Ocean

摘要:

根据大型拖网渔船“开欣”轮2010年7-10月在东南太平洋海域采集的211尾智利竹鱼样本，对其矢耳石形态特征进行观察与测量。东南太平洋智利竹荚鱼的矢耳石存在4个区，即前区、后区、背区和腹区。有明显的基叶，基叶均长于翼叶。对矢耳石的24项形态参数进行主成分分析，结果显示，耳石总长（L₁）、耳石中心到末端的距离（L₃）、耳石末端到翼叶的距离（L₁₁）、耳石末端到矩口的距离（L₁₃）可作为耳石长度特征参数，耳石中心到腹部的距离（L5）、耳石末端到腹部的距离（L₁₀）、耳石腹部到矩口的距离（L₁₈）、耳石翼叶的长度（L_{23）则可作为耳石宽度特征参数。耳石长度特征参数L1、L3、L11、L13与叉长和体重，以及耳石宽度特征参数L5、L10、L18与叉长和体重分别呈显著的幂函数关系（P=0<0.05），参数L23与叉长以及体重呈显著的指数函数关系（P=0<0.05）。}

Abstract:

A total of 211 Chilean jack mackerel (Trachurus murphyi) were collected by a largescale trawler named “KAIXIN” from July to October 2010 in the southeast Pacific Ocean. The morphologic features of their sagittas were observed and measured. The sagittas of Chilean jack mackerel have four parts: front part, back part, dorsal part and ventral part. It has an apparent rostrum which is longer than the antirostrum. The result of principal component analysis on 24 morphologic indices shows that the total sagitta length (L₁), distance from the core to the end(L₃), distance from the end to the antirostrum(L₁₁) and distance from the end to the intersection(L₁₃) can reflect the length features of sagitta, and distance from the core to the ventral(L5), distance from the end to the ventral(L₁₀), distance from the ventral to the intersection(L₁₈) and antirostrum length(L₂₃) can reflect its width features. The relationships between the featuredlength of sagitta including L₁, L₃, L₁₁ and L₁₃, and fork length as well as body weight were best described by power functions(P=0 <0.05). Also, the relationships between the featuredwidth of sagitta including L₅, L₁₀ and L₁₈, and fork length as well as body weight were best described by power functions(P=0<0.05). Antirostrum length (L₂₃) was best described by exponential functions with fork length as well as body weight (P=0<0.05).