The ornamental aquarium pet trade is a leading pathway for the introduction of aquatic invasive species. In addition to purchasing live organisms in stores, hobbyists are engaging more with alternative informal online marketplaces that enable peer-to-peer selling of aquarium organisms via auctions. Although growing in popularity, little is known regarding the global extent of informal marketplaces, including the taxonomy of species that are traded, their economic value, and the geographic routes by which live organisms are transported. In this study we use an automated web crawler to collect data on completed auctions between 2011 and 2017 from the largest informal market for aquarium hobbyists, AquaBid, to understand the market dynamics and trade flows of the informal retail market online. During the 7-year study period, the AquaBid website facilitated the estimated trade of 539,548 live freshwater animals, 579,700 fish eggs, and 31,431 plant assortments/bunches among 24,409 unique users who collectively placed 444,132 bids on 192,227 auctions, representing a total sale value of $6,015,030 USD. Source (seller) and recipient (buyer) locations of live organisms were distributed across 39 countries but concentrated largely in major cities of the United States and select European and southeast Asian countries. Our study is among the first to quantify geographic routes of live organism transport between specific locations on the landscape and demonstrates the highly diffuse and non-centralized nature of the informal aquarium trade. Evaluating the emerging challenges represented by informal online retail marketplaces is critical to create policy and regulatory solutions that minimize the transport of prohibited invasive species. Electronic supplementary material The online version of this article (10.1007/s10750-020-04407-7) contains supplementary material, which is available to authorized users.

中文翻译：

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在线拍卖市场作为水生入侵物种的全球途径

观赏水族馆宠物贸易是引入水生入侵物种的主要途径。除了在商店购买活体生物外，爱好者们还更多地参与替代的非正式在线市场，这些市场可以通过拍卖进行点对点销售。尽管越来越受欢迎，但人们对非正规市场的全球范围知之甚少，包括交易物种的分类、经济价值以及生物体运输的地理路线。在这项研究中，我们使用自动网络爬虫从最大的水族馆爱好者非正式市场 AquaBid 收集 2011 年至 2017 年间已完成拍卖的数据，以了解在线非正式零售市场的市场动态和贸易流。在 7 年的学习期间，AquaBid 网站促成了 539,548 只活淡水动物、579,700 个鱼卵和 31,431 个植物品种/束的估计交易，在 24,409 名独立用户中，这些用户在 192,227 次拍卖中总共出价 444,132 次，总销售额为 6,015,030 美元。活生物体的来源（卖方）和接受者（买方）分布在 39 个国家，但主要集中在美国的主要城市以及部分欧洲和东南亚国家。我们的研究率先量化了景观上特定位置之间活生物体运输的地理路线，并展示了非正式水族馆贸易的高度分散和非集中性质。评估非正式在线零售市场所代表的新挑战对于制定政策和监管解决方案以最大限度地减少违禁入侵物种的运输至关重要。电子补充材料 本文的在线版本 (10.1007/s10750-020-04407-7) 包含补充材料，可供授权用户使用。