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（alien species）是指被引入其自然分布范围以外区域的生物，被认为是海洋生物多样性丧失的主要诱因之一。本研究旨在报道在厄瓜多尔境内发现的外来甲壳动物（alien crustacean）物种。研究通过对科学文献进行数字化检索，开展了文献综述工作。最终在厄瓜多尔境内共记录到10种外来甲壳动物，隶属于7科8属。其中仅有一种蟹类——厚纹蟹（Cardisoma crassum Smith, 1870）在加拉帕戈斯群岛被发现。其余物种包括藤壶（barnacles）、螯虾（crayfishes）以及淡水对虾（freshwater prawns）。这些外来甲壳动物的原生分布范围涵盖印太海域、北美、亚洲及澳大利亚。主要的引入途径为水产养殖（aquaculture）与船舶运输。近期有报道称佛罗里达原螯虾（Procambarus alleni (Faxon, 1884)）作为水族观赏物种被引入，但目前尚不清楚其在自然环境中的存续情况。自20世纪60年代以来，厄瓜多尔每十年便会新增一种外来甲壳动物物种。另有部分物种曾被报道为厄瓜多尔外来物种，包括多纹藤壶（Amphibalanus improvisus (Darwin, 1854)）、网纹藤壶（Amphibalanus reticulatus (Utinomi, 1967)）以及桡足类的鲤锚头鳋（Lernaea cyprinacea Linnaeus, 1758），但这些物种当前的种群现状仍需进一步验证。此外，藤壶Dosima fascicularis (Ellis and Solander, 1786)在加拉帕戈斯群岛仅有偶见记录，鉴于其具有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。由于相关领域已发表的研究较为匮乏且存在分类学（taxonomic）难题，目前记录的厄瓜多尔外来甲壳动物物种清单尚不完整。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（aquatic ecosystems）造成的影响。