基于角质颚外部形态特征的曼氏无针乌贼2个地理群体判别

Identification of Two Geographic Populations of Sepiella maindroni Based on Rostrum’s External Morphological Characters

【目的】对春季舟山和洞头海域曼氏无针乌贼(Sepiella maindroni)角质颚的形态学参数进行分析,为探讨2个群体基于角质颚的判别建立依据。【方法】根据2021年3-4月在舟山和洞头海域采集的曼氏无针乌贼样品,提取角质颚共602对,测量角质颚12个形态指标数据,将数据进行标准化处理后对舟山群体和洞头群体的形态差异进行分析,并建立不同群体的判别函数。【结果】两个群体在胴长和体质量上均存在显著差异(P<0.05)。舟山和洞头群体角质颚形态学参数雌性均大于雄性。均数差异性检验认为,同一群体不同性别角质颚上头盖长、上脊突长、上侧壁长、上喙长、下翼长、下喙长和下喙宽均存在显著差异(P<0.05),同一性别不同群体角质颚上头盖长、上脊突长、上侧壁长、上喙长、下侧壁长、下翼长和下喙长均存在显著差异(P<0.05)。角质颚形态参数经主成分分析,认为上喙长、下喙宽和下脊突长最适合用来表征舟山群体角质颚的生长,上喙宽和下喙宽最适合用来表征洞头群体角质颚的生长。【结论】利用角质颚对两群体样本分性别建立了判别函数,总判别正确率均高于60%,所划分群体在部分形态指标上差异明显,具有一定可信度。

【Objective】The morphological parameters of rostrums of sepiella maindroni in Zhoushan and Dongtou sea areas in spring were analyzed in order to lay the basis for the identification of the two populations based on their rostrums’ morphological characters 【Method】According to the Sepiella maindroni samples collected in Zhoushan and Dongtou waters from March to April 2021, a total of 602pairs of rostrums were extracted, and 12 morphological index data of rostrums were measured. After the data were standardized, the morphological differences between Zhoushan and Dongtou populations of S. maindroni were analyzed, and the discriminant functions of different populations of S. maindroni were established. 【Result】 There were significant differences in mantle length(ML) and body mass between the two populations(P < 0.05). The morphological parameters of rostrums in Zhoushan and Dongtou populations of S. maindroni were larger in females than in males. The mean difference test showed that there were significant differences in rostrum’s UHLs(upper hood length), UCLs(upper crest length), ULWLs(upper lateral wall length), URLs(upper rostrum length), LWLs(lower wing length),LRLs(lower rostrum length)and LRWs(lower rostrum width)of different genders in the same population(P < 0.05). There were significant differences in UHLs, UCLs, ULWLs, URLs, LLWLs(lower lateral wall length), LWLs and LRLs between the same genders and different populations(P < 0.05). Principal component analysis of rostrum morphological parameters showed that URLs, LRWs and LCLs(lower crest length) were the most suitable for characterizing the growth of rostrums in Zhoushan population, and URWs and LRWs were the most suitable for characterizing the growth of rostrums in Dongtou population.【Conclusion】Using the rostrums, a discriminant function was established for the two populations, and the total identification accuracy was higher than 60%. The divided groups have obvious differences in some morphological indicators, which has a certain degree of credibility.