基于DNA条形码技术的永暑礁泻湖鱼卵鉴定研究

The identification analysis of fish eggs from lagoon of Yongshu Reef based on DNA barcoding technology

为了解南海珊瑚礁鱼类的产卵时间、产卵地点和种类分布,本研究以南海永暑礁泻湖鱼卵为研究对象,根据形态学特征和DNA条形码序列信息对其进行种属鉴定分析。71个鱼卵样品根据形态学特征分为圆形和椭圆形2种类型,圆形鱼卵44个,椭圆形鱼卵27个。利用DNA条形码技术扩增测序获得了30个鱼卵样品的线粒体COI条形码序列,经BOLD数据库比对分析显示30个鱼卵样品均可鉴定到种,分属于1个目,7个科,13个种。双斑栉齿刺尾鱼有10个鱼卵,白尾栉齿刺尾鱼有4个鱼卵,为该海域的优势种类,其余各种类均为1~2个鱼卵。根据线粒体COI序列计算种内的K2P(Kimura-2-parameter)遗传距离为0.002,同一个属种间的遗传距离为0.004~0.132,而同一个科不同属间的遗传距离为0.117~0.185。该研究结果表明DNA条形码技术可以作为鉴定南沙群岛珊瑚礁海域鱼卵的有效方法,能被广泛应用于南沙群岛珊瑚海区域鱼卵和仔稚鱼的鉴定工作。

The fish eggs from Yongshu reef lagoon of Nansha islands was researched in this stydy.The species identifications of fish egges were carried out by morphological features and DNA barcoding technology to understand the spawning time,spawning sites and species distribution for coral fish from South China Sea.The spherical and elliptical types were set apart from 71 fish eggs,there were 44 spherical eggs and 27 elliptical eggs.The mitochondrial COI sequences of 30 fish eggs were amplified and sequenced,then these sequences were respectively compared with the reference database of BOLD system.The results showed that all the 30 fish eggs could be identified to species level,which belonged to 1 order,7 families and 13 species.There were 10 eggs belonging to Ctenochaetus binotatus and 4 eggs belonging C.flavicauda,which were dominant species in Yongshu lagoon reef.The rest of species only had 1 2 eggs.The coral reef areas of Nansha islands were firstly confirmed to be important spawning site of Decapterus maruadsi.The Kimura-2-parameter(K2P)genetic distance between barcode sequences within species was 0.2%,whereas interspecific divergences among species within genera was 0.4%-13.2%,and intergeneric divergences among genera within families was 11.7%18.5%.These results showed that DNA barcoding technology was an effective method to identify fish egg,which would be widely applied to identify fish eggs and larvae for studying the spawning time,spawning sites and species distribution of fish from coral reef region of Nansha islands in South China Sea.