Due to the morphological similarity between some billfish species, the International Commission for the Conservation of Atlantic Tunas (ICCAT) recommends the use of molecular tools to identify billfish at the species level to properly manage this imperiled group. In this study, species-specific swordfish and billfish identification was carried out by using PCR-RFLP and multiplex PCR of the mitochondrial COI gene. Samples were obtained during landings of the tuna fleet at the Public Fisheries Port of Santos (PFPS) and in the General Warehouse Company of São Paulo (CEAGESP), Brazil. A total of 87 samples from PFPS were identified: Kajikia albida, Tetrapturus georgii, T. pfluegeri, Makaira nigricans, and Istiophorus platypterus. At CEAGESP, 432 individuals were collected, and three species were detected: Xiphias gladius, I. platypterus and T. georgii. Some samples presented an unknown band pattern for PCR-RFLP, which were sequenced and identified as X. gladius. These findings demonstrate that billfishes protected by law are being caught by industrial fisheries, but they are not traded at the CEAGESP. We advocate continuous onboard and of landings fishing monitoring using molecular identification tools in accordance with ICCAT recommendations. We provided evidence that DNA-based methods are efficient in overcoming billfish misidentification in the Atlantic Ocean.

由于某些比目鱼物种之间的形态相似，国际大西洋金枪鱼养护委员会（ICCAT）建议使用分子工具在物种水平上鉴定比目鱼，以适当地管理这一受害群体。在这项研究中，通过使用PCR-RFLP和线粒体COI基因的多重PCR进行了物种特异性箭鱼和比目鱼的鉴定。在金枪鱼船队降落在桑托斯公共渔业港口（PFPS）和巴西圣保罗总仓库公司（CEAGESP）期间获得了样本。总共从PFPS中鉴定出87个样品：白叶假丝酵母（Kajikia albida），吉氏Tetrapturus georgii，T。pfluegeri，Makaira nigricans和Istiophorus platypterus。在CEAGESP上，收集了432个个体，并检测到3个物种：剑兰（Xphipas gladius），鸭嘴兽（I. platypterus）和乔治哥（T. georgii）。一些样品呈现出未知的PCR-RFLP谱带模式，被测序并鉴定为X.gladius。这些发现表明，受法律保护的bill鱼正被工业化捕捞，但并未在CEAGESP上进行交易。我们主张根据ICCAT的建议，使用分子识别工具对船上和登陆捕鱼进行连续监视。我们提供的证据表明，基于DNA的方法可以有效克服大西洋中的比目鱼误认。