Clathrina aurea was considered endemic to Brazil before being recorded from the Pacific (Peru) and the Caribbean Sea. We assessed the morphological variability, phylogeographic pattern and population genetic structure of the species across its geographic range to understand how habitat fragmentation/reduction can affect a widely distributed species with supposedly low dispersal capability. Samples from 15 localities in the Caribbean Sea (n = 8), Brazil (n = 5), and Peru (n = 2) were studied. Morphological analyses included characterisation of external morphology, skeleton composition, and spicules morphometry. Phylogenetic trees and haplotype network were constructed using rDNA sequences. Population structure was assessed using microsatellite loci (F_ST fixation index and Discriminant Analysis of Principal Components). Morphological traits were consistent with C. aurea, although certain differences have been found, possibly due to environmental factors (temperature and pH). Phylogenetic analyses corroborated the conspecificity of the individuals and indicated higher genetic variability in individuals from Brazil and Caribbean, compared to Peru. Phylogeographic analyses indicated that Brazil had the oldest population of C. aurea, suggesting the expansion of this species across the Amazon River to the Caribbean and its connectivity through intermediate populations (e.g., Abrolhos). Population structure analyses also revealed high levels of genetic connectivity between the Caribbean and Northeast Brazil and among Southeast Brazilian localities. All analyses indicated isolation or restricted gene flow between Pacific and Atlantic populations. This, combined with the reduced genetic diversity in Peru and the supposedly limited larval dispersal capability, suggest a possible non-natural dispersion; however, we cannot exclude other hypotheses.

Clathrina aurea被认为是巴西特有的，然后才从太平洋（秘鲁）和加勒比海被记录下来。我们评估了该物种在其地理范围内的形态变异性、系统地理学模式和种群遗传结构，以了解栖息地破碎化/减少如何影响分布广泛且扩散能力较低的物种。研究了来自加勒比海 ( n  = 8)、巴西 ( n  = 5) 和秘鲁 ( n  = 2) 15 个地区的样本。形态学分析包括外部形态特征、骨骼组成和针状体形态测量学。系统发育树和单倍型网络是使用rDNA 序列构建的。使用微卫星评估种群结构基因座（F _ST固定指数和主成分判别分析）。形态特征与C. aurea一致，尽管已发现某些差异，这可能是由于环境因素（温度和 pH 值）所致。系统发育分析证实了个体的同源性，并表明与秘鲁相比，来自巴西和加勒比海地区的个体具有更高的遗传变异性。系统地理学分析表明，巴西拥有最古老的C. aurea种群，表明该物种跨越亚马逊河扩展到加勒比地区，并通过中间种群（例如，Abrolhos）进行连接。人口结构分析还揭示了加勒比地区和巴西东北部之间以及巴西东南部地区之间的高水平遗传连通性。所有分析都表明太平洋和大西洋种群之间存在隔离或基因流动受限。再加上秘鲁遗传多样性减少和幼虫传播能力有限，表明可能存在非自然传播；然而，我们不能排除其他假设。