Abstract The invasive bivalve Mytilopsis sallei caused several economic and ecological impacts in Asia. In Brazil, M. sallei was first reported in 2004, and thus far, little is known about its ecological impact on Brazilian estuaries. The present study aims to evaluate the abundance and distribution of M. sallei and to analyse the environmental factors that led to the establishment of this species in a Brazilian Northeast estuary. Sampling was carried out in six stations along the estuary, covering a broad spectrum of salinities. Results showed that M. sallei was the most abundant benthic species in this estuary, although it was not broadly distributed, occurring only in one station (S1), the most polluted and the one with the lowest salinities (mean 17.3 ± 11.56), which was the abiotic factor controlling the distribution of M. sallei. This station also had the lowest diversity of species (H′ = 0.3269). The main M. sallei microhabitat was the pneumatophores roots from mangrove trees and decomposing wood. Despite the high abundance of M. sallei in S1, this species experienced negative effect of other benthic species suggesting that its distribution was limited by the high abundance of native species in other stations. Our results suggest that the distribution of M. sallei is influenced by a set of characteristics: preference for low salinity, favourable substrate type, tolerance to pollutants, and less direct competitors. Understanding how invasive species are distributed and relate to native species will provide more robust strategies to help maintain environmental health that ultimately will prevent the expansion of M. sallei population.

中文翻译：

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环境因素对巴西东北海岸外来物种 Mytilopsis sallei (Récluz, 1849) (Bivalvia: Dreissenidae) 分布的影响

摘要 入侵的双壳类动物 Mytilopsis salei 在亚洲造成了若干经济和生态影响。在巴西，M. sallei 于 2004 年首次被报道，迄今为止，对其对巴西河口的生态影响知之甚少。本研究旨在评估 M. sallei 的丰度和分布，并分析导致该物种在巴西东北河口建立的环境因素。采样是在沿河口的六个站点进行的，涵盖了广泛的盐度。结果表明，M. sallei 是该河口底栖物种数量最多的物种，但分布不广，仅出现在一个站（S1），污染最严重，盐度最低（平均 17.3 ± 11.56）。是控制 M. sallei 分布的非生物因素。该站的物种多样性也最低（H' = 0.3269）。M. sallei 的主要微生境是来自红树林和腐烂木材的 pneumatophores 根。尽管 S1 中的 M. sallei 丰度高，但该物种受到其他底栖物种的负面影响，表明其分布受到其他站点本地物种高丰度的限制。我们的结果表明，M. sallei 的分布受一系列特征的影响：对低盐度的偏好、有利的底物类型、对污染物的耐受性以及较少的直接竞争者。了解入侵物种的分布方式以及与本地物种的关系将提供更强有力的策略来帮助维持环境健康，最终防止 M. salle 种群的扩张。