作　　者： ; ;

机构地区： 暨南大学

出　　处： 《海洋渔业》 2020年第1期1-9,共9页

摘　　要： 为明确中国马鲅科(Polynemidae)鱼类的分类地位,测定了中国7省10个地点马鲅科鱼类3属5种33条COI基因5′端序列,结合GenBank下载的5属16种41条同源序列,共分析了6属20种马鲅科鱼类DNA条形码。结果显示,20种鱼类种间平均遗传距离为19.6%,是种内平均遗传距离0.9%的22倍;其中14种形成了单系分支,支持其物种有效性。四指马鲅(Eleutheronema tetradactylum)和多鳞四指马鲅(E.rhadinum)种间遗传距离(16.0%)是种内平均遗传距离(1.2%)的13倍,支持将二者作为2个独立物种的分类处理。多鳞四指马鲅种内遗传距离(2.3%)大于2%,形成了2个自展数据支持率为99%的分支,分支间遗传距离(4.8%)是分支内平均遗传距离(0.1%)的48倍,表明在中国沿海分布的多鳞四指马鲅有可能存在2个亚种或隐藏种。黑斑多指马鲅(Polydactylus sextarius)与马达加斯加多指马鲅(P.malagasyensis)外部形态极为相似,种间遗传距离仅为1.0%,且在分子系统树上镶嵌混杂为一支,仅根据分子数据结果,推测二者可能为同一物种;但由于没有可检视的标本,也不能排除GenBank序列种名注释中形态鉴定出错的可能。马伦氏多指马鲅(P.mullani)与七丝指马鲅(Filimanus heptadactylus)也混为1支,分支内遗传距离仅为0.1%;如果不是GenBank序列种名注释出错,则二者应为同一物种。GenBank序列中来源于北部湾的六丝多指马鲅(P.sexfilis),则可能是黑斑多指马鲅的错误鉴定。 To determine species status of some Polynemid species,5 of mitochondrial COI gene sequences of 33 individuals of 5 species of 3 genera from 10 locations in the coastal waters of China were sequenced,and 41 homologous sequences of 16 species of 5 genera were downloaded from GenBank,the combined analyses revealed that the average genetic distance among 20 species(19.6%)was about 22 times those within species(0.9%),and 14 species were monophyletic,supporting their species status.The genetic distance between Eleutheronema tetradactylum and Eleutheronema rhadinum(16.0%)was about 13 times the average genetic distance within species(1.2%),confirming that Eleutheronema tetradactylum and Eleutheronema rhadinum were two different species.The intraspecies genetic distance of Eleutheronema rhadinum(2.3%)was more than 2%,and was further divided into 2 subclades with 99%bootstrap support,and the genetic distances between the subclades(4.8%)were about 48 times those(0.1%)within subclades,which conformed to the“10×”rule,suggesting that Eleutheronema rhadinum in coastal waters of China might have evolved to two subspecies or two different species.Polydactylus sextarius and Polydactylus malagasyensis were very similar in morphological charateristics,and were interwined in the same clade,and interspecies genetic distance was 1.0%,thus if not misidentified morphologically,the two species might be synonyms.Polydactylus mullani and Filimanus heptadactylusalso were interwined in the same clade and the genetic distance between species was only 0.1%,if species identification in GenBank were not wrong,they should be treated as synonyms.Polydactylus sexfilis collected from the Beibu Bay appeared in the same clade with morpholically checked Polydactylus sextarius from various sites in coastal waters of China,which suggested that the sequences were misidentified.

关 键 词： 马科 条形码 基因

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