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A new labrid fish species,Halichoeres sanchezin. sp., is described from eight specimens collected in the Revillagigedo Archipelago in the tropical eastern Pacific Ocean, off the coast of Mexico. The new species belongs to theHalichoeres melanotisspecies complex that is found throughout the region, differing by 2.4% in the mtDNA cytochrome c oxidase I sequence from its nearest relative,H. melanotisfrom Panama, and 2.9% fromHalichoeres salmofasciatusfrom Cocos Island, off Costa Rica. The complex is distinguished from others in the region by having a black spot on the opercular flap and a prominent black area on the caudal fin of males. The juveniles and initial phase of the new species closely resemble those ofH. salmofasciatusandHalichoeres malpelofrom Malpelo Island of Colombia, differing in having an oblong black spot with a yellow dorsal margin on the mid-dorsal fin of initial-phase adults as well as on juveniles. In contrast, the terminal-phase male color pattern is distinct from other relatives, being vermilion to orangish brown with dark scale outlines, a white patch on the upper abdomen, and a prominent black band covering the posterior caudal peduncle and base of the caudal fin. The new species adds to the list of endemic fish species for the isolated archipelago and is an interesting case of island endemism in the region. The discovery was made during the joint 2022 collecting expedition to the archipelago, which featured a pioneering collaborative approach to an inventory of an island ichthyofauna, specifically including expert underwater photographers systematically documenting specimensin situ, before hand-collection, and then photographed fresh, tissue-sampled, and subsequently vouchered in museum collections. 

Systematic relationships within the Cirrhitoidei, a suborder of five closely related families, have been uncertain for over a century. This is particularly true in reference to the families Cheilodactylidae and Latridae, which have been revised numerous times over the past several decades. Species that have been included in these two families are found in temperate regions around the world, which has led to regionally-focused studies that have only exacerbated taxonomic confusion. Here we examine systematic relationships within the Cheilodactylidae and the Latridae using ultraconserved genomic elements with near complete taxonomic sampling, and place our results in the context of the Cirrhitoidei. Our results agree with previous findings suggesting that Cheilodactylidae is restricted to two South African species, with the type species of the family, Cheilodactylus fasciatus Lacépède, forming a clade with C. pixi Smith that together is more closely related to the Chironemidae than to other species historically associated with the genus. We also strongly resolve the relationships of species within the Latridae. As a result of our analyses we revise the taxonomy of Latridae, name a new genus, and re-elevate Chirodactylus and Morwong. 

Abstract A wide variety of species are distinguished by slight color variations. However, molecular analyses have repeatedly demonstrated that coloration does not always correspond to distinct evolutionary histories between closely related groups, suggesting that this trait is labile and can be misleading for species identification. In the present study, we analyze the evolutionary history of sister species ofPrionurussurgeonfishes in the Tropical Eastern Pacific (TEP), which are distinguished by the presence or absence of dark spots on their body. We examined the species limits in this system using comparative specimen‐based approaches, a mitochondrial gene (COI), more than 800 nuclear loci (Ultraconserved Elements), and abiotic niche comparisons. The results indicate there is a complete overlap of meristic counts and morphometric measurements between the two species. Further, we detected multiple individuals with intermediate spotting patterns suggesting that coloration is not diagnostic. Mitochondrial data recovered a single main haplotype shared between the species and all locations resulting in a complete lack of structure (Φ_ST = 0). Genomic analyses also suggest low levels of genetic differentiation (F_ST = 0.013), and no alternatively fixed SNPs were detected between the two phenotypes. Furthermore, niche comparisons could not reject niche equivalency or similarity between the species. These results suggest that these two phenotypes are conspecific and widely distributed in the TEP. Here, we recognizePrionurus punctatusGill 1862 as a junior subjective synonym ofP. laticlavius(Valenciennes 1846). The underlying causes of phenotypic variation in this species are unknown. However, this system gives insight into general evolutionary dynamics within the TEP.