Updated checklist and analysis of completeness of the marine fish fauna of Isla del Coco, Pacific of Costa Rica: Fishes Checklist

Isla del Coco, Costa Rica, is one of the five groups of oceanic islands of the Eastern Tropical Pacific (ETP), and is considered one of the most diverse. Since the mid-19th century, it has been the target of a number of scientific research expeditions that have produced specimen collections which are housed in natural history museums around the world. The fish assemblage of Isla del Coco is considered one of the most speciose and best documented group of marine organisms of the island. Despite this, recent work has resulted in a need to update the checklist for this important group. We performed a completeness analysis of the ichthyofauna of Isl del Coco based on scientific publications and reports of expeditions, specimens in foreign and national collections, and field surveys. We confirmed the presence of 514 species of marine fishes, representing an increase of approximately 23% compared to what was previously reported. From a habitat perspective, 58 % of this assemblage is typically reef fishes, while the remaining 42% are deep-water, and pelagic species. The average expected reef fish species richness is 318.2 ± 7.3, suggesting that the local inventory represents 93.7 % of the expected total richness. Our updated list and greater number of species has particular relevance to the conservation efforts at Isla del Coco, since current conservation efforts are protecting at least 50 % of ETP fish species and about 40 % of Costa Rica’s Pacific fish species.

哥斯达黎加科科斯岛（Isla del Coco）是东热带太平洋（Eastern Tropical Pacific, ETP）五大洋岛群之一，被认为是该区域物种多样性最高的区域之一。自19世纪中期以来，该岛便成为诸多科学考察活动的目标，所采集的标本现收藏于全球多家自然历史博物馆。科科斯岛的鱼类组合被视为该岛海洋生物中物种最丰富、记录最完备的类群之一。尽管如此，近期的研究表明亟需更新这一重要类群的物种名录。本研究基于科学文献、考察报告、国内外馆藏标本及实地调查数据，对科科斯岛的鱼类区系（ichthyofauna）开展完整性分析。本研究确认该海域共分布514种海洋鱼类，较此前报道的物种数量增长约23%。从栖息环境来看，该鱼类组合中58%为典型的礁栖鱼类，剩余42%为深水鱼类和远洋鱼类。礁栖鱼类的预期物种丰富度均值为318.2±7.3，表明本次本地物种调查覆盖了预期总丰富度的93.7%。本研究更新的物种名录及新增的物种数量，对科科斯岛的保护工作具有重要意义：当前的保护措施已覆盖至少50%的东热带太平洋鱼类物种，以及约40%的哥斯达黎加太平洋海域鱼类物种。