Chaetodontidae, known as butterflyfishes, are typical fish in coral ecosystems, exhibiting remarkable interspecific differences including body colour patterns and feeding ecology. In this study, we report genomes of three butterflyfish species (Chelmon rostratus, Chaetodon trifasciatus and Chaetodon auriga) and a closely related species from the Pomacanthidae family, Centropyge bicolour, with an average genome size of 65,611 Mb. Chelmon rostratus, comprising 24 chromosomes assembled to the chromosome level, could be served as a reference genome for butterflyfish. By conducting a collinearity analysis between butterflyfishes and several fishes, we elucidated the specific and conserved genomic features of butterflyfish, with particular emphasis on novel genes arising from tandem duplications and their potential functions. In addition to the two melanocyte-specific tyr genes commonly found in fish, we found the gene tyrp3, a new tyrosinase-related proteins gene in the reef fish, including butterflyfish and clownfish, implicating their involvement in the pigmentation diversity of fish. Additionally, we observed a tandem duplication expansion of three copies of nell1 gene in C. rostratus genome, which likely contribute to its unique jaw development and distinctive morphology of its sharp mouth. These results provided valuable genomic resources for further investigations into the genetic diversity and evolutionary adaptations of reef fish.

中文翻译：

---

蝴蝶鱼的染色体水平基因组揭示了独特颜色图案和形态特征的基因组特征。

毛齿鱼科（Chaetodontidae）被称为蝴蝶鱼，是珊瑚生态系统中的典型鱼类，表现出显着的种间差异，包括体色模式和摄食生态。在这项研究中，我们报告了三种蝴蝶鱼物种（Chelmon rostratus、Chaetodon trifasciatus 和 Chaetodon auriga）以及与 Pomacanthidae 家族密切相关的物种 Centropyge bicolor 的基因组，平均基因组大小为 65,611 Mb。Chelmon rostratus 由 24 条染色体组成，在染色体水平上组装，可以作为蝴蝶鱼的参考基因组。通过对蝴蝶鱼和几种鱼类之间进行共线性分析，我们阐明了蝴蝶鱼特定且保守的基因组特征，特别强调串联重复产生的新基因及其潜在功能。除了鱼类中常见的两个黑色素细胞特异性 tyr 基因外，我们还在珊瑚鱼（包括蝴蝶鱼和小丑鱼）中发现了tyrp3基因，这是一种新的酪氨酸酶相关蛋白基因，表明它们参与了鱼类的色素沉着多样性。此外，我们观察到 C. rostratus 基因组中 nell1 基因的三个拷贝的串联重复扩增，这可能有助于其独特的下颌发育和锋利嘴的独特形态。这些结果为进一步研究礁鱼的遗传多样性和进化适应提供了宝贵的基因组资源。