Arroyave Jairo, Stiassny Melanie L J
Division of Vertebrate Zoology, Department of Ichthyology, American Museum of Natural History Central Park West at 79th St., New York, New York, 10024.
Ecol Evol. 2014 Dec;4(23):4534-42. doi: 10.1002/ece3.1321. Epub 2014 Nov 19.
DNA barcoding was used to investigate dietary habits and prey selection in members of the African-endemic family Distichodontidae noteworthy for displaying highly specialized ectoparasitic fin-eating behaviors (pterygophagy). Fin fragments recovered from the stomachs of representatives of three putatively pterygophagous distichodontid genera (Phago, Eugnathichthys, and Ichthyborus) were sequenced for the mitochondrial gene co1. DNA barcodes (co1 sequences) were then used to identify prey items in order to determine whether pterygophagous distichodontids are opportunistic generalists or strict specialists with regard to prey selection and, whether as previously proposed, aggressive mimicry is used as a strategy for successful pterygophagy. Our findings do not support the hypothesis of aggressive mimicry suggesting instead that, despite the possession of highly specialized trophic anatomies, fin-eating distichodontids are opportunistic generalists, preying on fishes from a wide phylogenetic spectrum and to the extent of engaging in cannibalism. This study demonstrates how DNA barcoding can be used to shed light on evolutionary and ecological aspects of highly specialized ectoparasitic fin-eating behaviors by enabling the identification of prey species from small pieces of fins found in fish stomachs.
DNA条形码技术被用于研究非洲特有的歧须鮠科鱼类的饮食习惯和猎物选择，该科鱼类以表现出高度特化的体外寄生食鳍行为（食鳍癖）而闻名。从三个假定有食鳍癖的歧须鮠属（Phago、Eugnathichthys和Ichthyborus）代表的胃中回收的鳍碎片，对其线粒体基因细胞色素c氧化酶亚基I（co1）进行测序。然后利用DNA条形码（co1序列）来识别猎物，以确定食鳍癖歧须鮠在猎物选择方面是机会主义的通才还是严格的专才，以及是否如先前所提出的，攻击性拟态被用作成功进行食鳍癖的一种策略。我们的研究结果不支持攻击性拟态的假设，相反表明，尽管拥有高度特化的营养解剖结构，但食鳍歧须鮠是机会主义的通才，捕食来自广泛系统发育谱系的鱼类，甚至到了同类相食的程度。这项研究展示了DNA条形码技术如何通过从鱼胃中发现的小鳍片识别猎物物种，从而揭示高度特化的体外寄生食鳍行为的进化和生态方面。
