1. Elasmobranchs are apex predators that play a crucial role in marine ecosystems by regulating the dynamics of food webs, as well as connecting different trophic levels across habitats.
2. The large-scale removal of elasmobranchs impacts the energy transfer in trophic interactions. The pressure of unsustainable fisheries is considerable, as most elasmobranchs have reproductive strategies that render them unable to recover their demographic status after depletion.
3. In Brazil, elasmobranchs are broadly commercialized under the generalist common name of ‘cação’ (namely, shark meat). This allows threatened species to be commercialized and makes the tracking of different species difficult.
4. DNA barcoding of the Cytochrome c oxidase subunit 1 (COI) gene was applied to identify the different species sold as ‘cação’ along the coastline of Brazil. Fifty-seven samples from 33 cities in 15 coastal states of Brazil were purchased and analysed.
5. Bioinformatic analyses revealed the presence of 17 species that were sold as ‘cação’. Among them, Prionace glauca (blue shark) was the most abundant. Other species, listed as Endangered under the IUCN Red List of Threatened Species, were also uncovered as being in the shark meat trade, such as Sphyrna lewini (scalloped hammerhead), Isurus paucus (longfin mako shark), and Squatina guggenheim (angular angel shark).
6. These findings have reinforced the necessity to correctly label the commercialized species. Public actions towards species-specific management plans must be applied, as well as monitoring the supervised allied educational programmes.

中文翻译：

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出售生物多样性：鲨鱼肉市场威胁到巴西的软骨鱼

1. Elasmobranchs 是顶级捕食者，通过调节食物网的动态以及连接不同栖息地的不同营养水平，在海洋生态系统中发挥着至关重要的作用。
2. 大量去除弹性鳃会影响营养相互作用中的能量转移。不可持续渔业的压力是相当大的，因为大多数 elasmobranchs 有繁殖策略，使它们在枯竭后无法恢复其人口状况。
3. 在巴西，棘鳃类动物在通用通用名称“cação”（即鲨鱼肉）下被广泛商业化。这使得受威胁的物种可以商业化，并使不同物种的追踪变得困难。
4. 应用细胞色素 c 氧化酶亚基 1 ( COI ) 基因的DNA 条形码来识别沿巴西海岸线以“cação”出售的不同物种。购买并分析了来自巴西 15 个沿海州的 33 个城市的 57 个样品。
5. 生物信息学分析显示存在以“cação”名义出售的 17 种物种。其中以Prionace glauca（蓝鲨）数量最多。在世界自然保护联盟濒危物种红色名录中列为濒危物种的其他物种也被发现参与鲨鱼肉贸易，例如Sphyrna lewini（扇形双髻鲨）、Isurus paucus（长鳍灰鲭鲨）和Squatina guggenheim（角天使鲨） ）。
6. 这些发现加强了正确标记商业化物种的必要性。必须针对特定物种的管理计划采取公共行动，并监督受监督的相关教育计划。