Genome size (GS) is known to vary widely among fishes. However, evolutionary drivers that shape this variation are largely unknown in Pomacentridae. GS information is available for several Pomacentridae species, which have adapted over evolutionary time mainly in reef environments. In the present study, we used comparative phylogenetic methods to evaluate the role of ecological variables in driving GS variation in 49 species of this family. We also aimed to understand how GS evolved, evaluating five continuous character evolution models. We found that GS varied 1.98-fold, with C-values ranging from 0.68 pg (Pomacentrus auriventris) to 1.35 pg (Chrysiptera hemicyanea). Our phylogenetic analyses, based on mitochondrial and nuclear sequences, revealed that Pomacentridae diversification into two main clades occurred ~58 Mya, with the two clades showing distinct evolutionary trends. Character reconstruction of GS values revealed expansions and retractions in GS with convergences and parallelisms in different lineages. We also found a significant association between GS and body size and proxies of niche breadth (temperature and salinity), suggesting that species with larger genomes tend to occupy a wider niche breadth. Thus, GS variation may influence the life histories of Pomacentridae fishes, independently of their evolutionary relationships.

已知鱼类之间的基因组大小（GS）差异很大。但是，形成这种变异的进化驱动力在香囊菌科中却鲜为人知。GS信息可用于几种疟原虫科，这些科目已随着进化时间而变化，主要是在珊瑚礁环境中。在本研究中，我们使用了比较的系统发育方法来评估生态变量在驱动该家族49个物种中GS变异中的作用。我们还旨在了解GS的演变过程，评估了五个连续的角色进化模型。我们发现GS的变化范围为1.98倍，C值范围为0.68 pg（Pomacentrus auriventris）至1.35 pg（Chrysiptera hemicyanea））。我们基于线粒体和核序列的系统发育分析表明，禾本科（Pomacentridae）分化为两个主要进化枝，发生在〜58 Mya，两个进化枝显示出明显的进化趋势。GS值的字符重建揭示了GS在不同谱系中具有收敛和平行性的扩展和缩回。我们还发现GS与体大小和生态位宽度的代理人（温度和盐度）之间存在显着关联，这表明具有较大基因组的物种倾向于占据更宽的生态位宽度。因此，GS的变异可能会独立于它们的进化关系而影响番茄对虾的生活史。