The Pacific epizoic brittle star Ophiothela mirabilis Verrill, 1867 has successfully established itself along the Southwestern Atlantic. While reports of this species show high densities and an expanding range throughout the Western Atlantic, specific knowledge regarding populations and their potential for distribution is scarce. We assess herein the current distribution and abundance patterns of O. mirabilis along the subtropical SW Atlantic coast while simultaneously employing ecological niche models (ENMs) to predict suitable habitats in the future. Ophiothela mirabilis is currently distributed in both poly- and euhaline estuarine and inner continental shelf areas. Population densities tend to increase from the inner shelf (≤ 492 individuals.m⁻²) to estuarine habitats (≥ 815 individuals.m⁻²), characterized by a 53.38% mean habitat suitability index, until being limited by unsuitable environmental habitats. Octocoral species are the most densely and frequently colonized hosts (up to 3.6 individuals.cm⁻² of host's area). Currently, occurrence records for O. mirabilis encompass disjunct habitats from Santa Catarina (S Brazil) to Southeast Florida (USA). Our ENMs predicted that O. mirabilis has the potential to further spread across the warm marine provinces of the Western Atlantic, as they are characterized by ≥40.72% of environmentally suitable habitats. The occurrence of the species correlates mainly to mean calcite concentration and mean sea surface temperature, which accounts for 56.97% of the performance of the ENMs. The high spreading capacity and the maintenance of dense abundances on hosts raises questions about its effects on recipient biodiversity and systems.

1867年，太平洋上的脆性恒星Ophiothela mirabilis Verrill在西南大西洋沿岸成功建立了自己的位置。虽然有关该物种的报道显示出高密度，并且范围遍及整个西大西洋，但有关种群及其分布潜力的专门知识却很少。我们在这里评估了亚热带西南大西洋沿岸的奇异O. mirabilis的当前分布和丰度模式，同时采用了生态位模型（ENMs）来预测未来的合适栖息地。奇异纲纲目前分布在多，真盐河口和内陆大陆架地区。内层种群密度趋于增加（≤492个个体。⁻²）到河口栖息地（≥815个个体.m ⁻²），其特征在于平均栖息地适宜性指数为53.38％，直到受到不合适的环境栖息地的限制为止。八叶树种是最密集和最常定殖的寄主（寄主面积最多3.6个个体^{。cm -2}）。目前，奇异芽孢杆菌的发生记录涵盖从圣卡塔琳娜州（巴西）到佛罗里达州东南部（美国）的不同生境。我们的ENM预测出奇异的O. mirabilis具有≥40.72％的环境适宜栖息地的特征，因此有潜力进一步扩散到西大西洋温暖的海洋省份。该物种的出现主要与方解石的平均浓度和平均海表温度有关，占ENMs性能的56.97％。寄主的高传播能力和密集密度的维持引起了人们对其对受体生物多样性和系统的影响的疑问。