Alien crustacean species recorded in Ecuador

Abstract Alien species are organisms introduced into an area outside of their natural range and are considered a major cause of biodiversity loss in the marine environment. The aim of this work is to report on the alien crustacean species observed in Ecuador. A bibliographic review was conducted using a digital search in the scientific literature. A total of ten alien species of crustaceans, representing eight genera in seven families, were encountered in Ecuador. The only crab, Cardisoma crassum Smith, 1870, was observed in the Galapagos Islands. The other species include barnacles, crayfishes, and freshwater prawns. Native ranges of the alien crustaceans include the Indo-Pacific region, North America, Asia, and Australia. Major introduction pathways are aquaculture and transport by ship. Procambarus alleni (Faxon, 1884) was reported recently as an aquarium species, but its presence in the natural environmental is currently unknown. One alien species has been introduced each decade since the 1960s. Some species (the barnacles Amphibalanus improvisus (Darwin, 1854), Amphibalanus reticulatus (Utinomi, 1967), and the copepod Lernaea cyprinacea Linnaeus, 1758) were reported as alien species for Ecuador but need verification regarding their current status. Additionally, the barnacle Dosima fascicularis (Ellis and Solander, 1786) presented an occasional record in the Galapagos Islands, but due to its dispersal ability and open ocean habitat it is not possible to conclude that this really is an alien species. The list of alien crustacean species recorded in Ecuador is considered incomplete due to both scarce published work regarding this topic and taxonomic problems. Therefore, it is necessary to carry out more research to establish a complete list of the alien species present in Ecuador and assess their impact on aquatic ecosystems.摘要：外来物种是指被引入其自然分布范围以外区域的生物，被普遍认为是引发海洋生物多样性丧失的主要诱因之一。本研究旨在报告在厄瓜多尔境内发现的外来甲壳类动物类群。研究通过对科学文献开展数字化检索，完成了系统性文献综述。本次研究共在厄瓜多尔境内记录到10种外来甲壳类动物，隶属于7科8属。其中唯一的蟹类为厚地蟹（Cardisoma crassum Smith, 1870），发现于加拉帕戈斯群岛。其余物种涵盖藤壶、螯虾以及淡水虾类群。这些外来甲壳类动物的原生分布范围涵盖印度-太平洋区域、北美洲、亚洲以及澳大利亚。其主要引入途径为水产养殖与船舶携运。近期有报道称艾伦原螯虾（Procambarus alleni (Faxon, 1884)）为水族观赏物种，但其在自然环境中的定居情况目前尚不明确。自20世纪60年代以来，厄瓜多尔每十年就会新增一种外来甲壳类物种。部分物种（如无纹藤壶（Amphibalanus improvisus (Darwin, 1854)）、网纹藤壶（Amphibalanus reticulatus (Utinomi, 1967)）以及桡足类鲤锚头鳋（Lernaea cyprinacea Linnaeus, 1758)）虽被报道为厄瓜多尔的外来物种，但其当前的种群存续状态仍需进一步验证。此外，束状船藤壶（Dosima fascicularis (Ellis and Solander, 1786)）在加拉帕戈斯群岛仅有偶发记录，鉴于其具备较强的扩散能力且栖息于远洋生境，目前无法确定其是否为真正的外来物种。由于相关公开研究匮乏且存在分类学争议，目前厄瓜多尔已记录的外来甲壳类物种名录仍不完整。因此，有必要开展更多研究以建立完整的厄瓜多尔外来物种名录，并评估其对水生生态系统造成的生态影响。