两种眉足蟹科蟹类的形态特征与遗传多样性研究

研究描述了解放眉足蟹和日本冠鞭蟹的形态特征，并基于线粒体COⅠ基因片段分析了解放眉足蟹和日本冠鞭蟹的遗传多样性现状。解放眉足蟹的主要形态特征为体白色，甲壳呈琵琶形，背部中线隆起，表面较光滑，步足扁平，指节弯曲明显；日本冠鞭蟹的主要形态特征为体红褐色，甲壳呈卵形，头胸甲长大于甲宽，有许多白色斑点，步足简化成铲，上有刚毛。在长度为659 bp的线粒体COⅠ基因片段上，解放眉足蟹20个个体共检测到15个单倍型，平均GC含量为33.26%，单倍型多样度为0.9421，核苷酸多样度为0.0059；日本冠鞭蟹20个个体共检测到15个单倍型，平均GC含量为47.65%，单倍型多样度为0.9415，核苷酸多样度为0.0061。基于K-2P模型计算得到解放眉足蟹和日本冠鞭蟹种间遗传距离为0.2705，解放眉足蟹个体间平均遗传距离为0.006，日本冠鞭蟹个体间平均遗传距离为0.006，种间遗传距离显著大于种内遗传距离。以Emerita emeritus为外群构建系统树，不同蝉蟹分别形成各自独立的分支，表明COⅠ基因可以作为蝉蟹DNA条形码辅助分类。

THE MORPHOLOGICAL CHARACTERS AND GENETIC DIVERSITY OF BLEPHARIPODA LIBERATE SHEN ANDLOPHOMASTIX JAPONICA

The present study described the morphological characters ofBlepharipoda liberate andLopoomastix japo-nica, and analyzed the genetic diversity of two species based onCOⅠ gene. The diagnostic characters ofB. liberate are as following: Carapace approximately 1.3 times longer than wide; strongly keeled medially; anterior margin with large rugosi spine on either side of ocular sinus; frontal region smooth with few low teeth posterior to rostrum. The diagnos-tic characters ofL. japonica are as following: Carapace approximately 1.2 times longer than wide; gently keeled medially; anterior margin with proximally broad and distally narrowing rugose outer-ocular spines on either side of ocular sinus, concave medially. The gene diversity and nucleotide diversity ofB. liberate based onCOⅠ gene were 0.942±0.043 and 0.0059±0.0034, respectively. The gene diversity and the nucleotide diversity ofL. japonica were 0.941±0.0048 and 0.0061±0.0035, respectively. The K-2P distance was 0.2705 between theB. liberate andL. japonica, and these two species were distributed into two distinct branches based on neighbor-joining tree analysis, which rein-forces the validity of DNA barcoding on classification of Blepharipodidae based onCOⅠ gene.