Marine ecosystems provide a wide variety of diverse habitats that frequently promote migration and ecological adaptation. The extent to which the geographic distribution of marine organism has reshaped by human activities remains underappreciated. The limitations intrinsic to morphology-based identification systems have engendered an urgent need for reliable genetic methods that enable the unequivocal recognition of fish species, particularly those that are prone to overexploitation and/or market substitution. In the present study, however, an attempt has been taken to identify two locally adapted fish species, Siganus sutor (Valenciennes, 1835) and Seriolina nigrofasciata (Rüppell, 1829) of order Perciformes, which happens to be the first record in Odisha coast, Bay of Bengal. The diagnostic characteristics of Siganus sutor are: dorsal fin XIII-10, anal fin VII-9, pectoral fin 15, pelvic fin II-3, while that of Seriolina nigrofasciata dorsal fin VI-I-35, anal fin I-17, pectoral fin 16, pelvic fin 5. All COI barcodes generated in this study were matched with reference sequences of expected species, according to morphological identification. Bayesian and likelihood phylogenetic trees were drawn based on DNA barcodes and all the specimens clustered in agreement with their taxonomic classification at the species level. The phylogeographic studies based on haplotype network and migration rates suggest that both the species were not panmitic and the high-frequency population distribution indicates successful migration. The result of this study provides an important validation of the use of DNA barcode sequences for monitoring species diversity and changes within a complex marine ecosystem.

中文翻译：

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形态和分子证据支持了两条鱼类的首次出现，它们来自印度孟加拉湾奥里萨哈海岸的海水中的两条鱼类：西加努斯捕食者（Valenciennes，1835年）和Seriolina nigrofasciata（Rüppell，1829年）（Actinopterygii：Perciformes）。

海洋生态系统提供了多种多样的生境，这些生境经常促进迁徙和生态适应。人类活动对海洋生物地理分布的影响程度仍未得到充分认识。基于形态学的识别系统固有的局限性导致迫切需要可靠的遗传方法，这些方法能够明确识别鱼类，特别是那些容易被过度开发和/或市场替代的鱼类。然而，在本研究中，已尝试鉴定两种本地适应的鱼类，即西加努斯捕食者（Valenciennes，1835年）和Seriolina nigrofasciata（Rüppell，1829年）订购的Perciformes，恰巧是孟加拉湾奥里萨邦海岸的第一笔记录。西加努斯（Saganus sutor）的诊断特征为：背鳍XIII-10，肛门鳍VII-9，胸鳍15，骨盆鳍II-3，而黑鳍金丝雀（Seriolina nigrofasciata）背鳍VI-I-35，肛门鳍I-17，胸鳍16，骨盆鳍5。根据形态学鉴定，本研究中生成的所有COI条码均与预期物种的参考序列匹配。贝叶斯和似然的系统发育树是根据DNA条形码绘制的，所有标本都按照其在物种级别上的分类进行了聚类。基于单体型网络和迁移率的系统地理学研究表明，这两个物种都不是泛虾类，高频种群分布表明迁移成功。这项研究的结果提供了使用DNA条形码序列监测复杂海洋生态系统中物种多样性和变化的重要验证。