Cirrhilabruswakanda, a new species of fairy wrasse from mesophotic ecosystems of Zanzibar, Tanzania, Africa (Teleostei, Labridae)

Cirrhilabrus finifenmaa (Teleostei, Labridae), a new species of fairy wrasse from the Maldives, with comments on the taxonomic identity of C. rubrisquamis and C. wakanda

Cirrhilabrus rubrisquamis is redescribed on the basis of the juvenile holotype and compared to known species of Cirrhilabrus. Examination of material from the Maldives identified as C. rubrisquamis reveal differences from the holotype collected from the Chagos Archipelago. Consequently, the Maldivian specimens are herein described as Cirrhilabrus finifenmaasp. nov., on the basis of the holotype and twelve paratypes. The new species differs from all congeners in having: males with anterior third to half of body bright magenta, peach to orange-pink posteriorly; lateral line with 22–26 pored scales (16–18 in the dorso-anterior series, 6–8 in the posterior peduncular series); tenth to eleventh dorsal-fin spine longest (14.0–15.5% SL); scales on the opercle, chest, isthmus, and anterior third of the body with a dark purple-red central region (purple in alcohol), the markings joining appearing crosshatched; dorsal, caudal, anal, and pelvic-fin rays purple in alcohol. Meristic details and coloration patterns of C. rubrisquamis are very similar to C. wakanda from Tanzania, Africa, although synonymy of both species cannot be determined without additional material from Chagos. This potential synonymy is briefly discussed; however, until such material becomes available, the taxonomic statuses of C. wakanda and C. rubrisquamis are here provisionally regarded as valid.

Redescription of Conniella apterygia Allen and its reassignment in the genus Cirrhilabrus Temminck and Schlegel (Teleostei: Labridae), with comments on cirrhilabrin pelvic morphology

Conniella apterygia is redescribed from re-examination of the holotype, two paratypes, and six additional specimens. The genus is closely allied to Cirrhilabrus, sharing similarities in general morphological and meristic details, but is separated from Cirrhilabrus and most other labrid fishes in lacking pelvic fins and a pelvic girdle. Recent molecular phylogenetic studies have provided strong evidence for the deep nesting of Conniella within Cirrhilabrus, contradicting its generic validity and suggesting that the loss of pelvic elements is autapomorphic. Consequently, the species is redescribed and assigned to the genus Cirrhilabrus, as Cirrhilabrus apterygia new combination. The pelvic morphologies of related cirrhilabrin labrids are discussed, and a new synapomorphy is identified for Paracheilinus.

Phylogenomic Analysis of Concatenated Ultraconserved Elements Reveals the Recent Evolutionary Radiation of the Fairy Wrasses (Teleostei: Labridae: Cirrhilabrus)

The fairy wrasses (genus Cirrhilabrus) are among the most successful of the extant wrasse lineages (Teleostei: Labridae), with their 61 species accounting for nearly 10% of the family. Although species complexes within the genus have been diagnosed on the basis of coloration patterns and synapomorphies, attempts to resolve evolutionary relationships among these groups using molecular and morphological data have largely been unsuccessful. Here we use a phylogenomic approach with a data set comprising 991 ultraconserved elements (UCEs) and mitochondrial COI to uncover the evolutionary history and patterns of temporal and spatial diversification of the fairy wrasses. Our analyses of phylogenetic signal suggest that most gene-tree incongruence is caused by estimation error, leading to poor resolution in a summary-coalescent analysis of the data. In contrast, analyses of concatenated sequences are able to resolve the major relationships of Cirrhilabrus. We determine the placements of species that were previously regarded as incertae sedis and find evidence for the nesting of Conniella, an unusual, monotypic genus, within Cirrhilabrus. Our relaxed-clock dating analysis indicates that the major divergences within the genus occurred around the Miocene-Pliocene boundary, followed by extensive cladogenesis of species complexes in the Pliocene-Pleistocene. Biogeographic reconstruction suggests that the fairy wrasses emerged within the Coral Triangle, with episodic fluctuations of sea levels during glacial cycles coinciding with shallow divergence events but providing few opportunities for more widespread dispersal. Our study demonstrates both the resolving power and limitations of UCEs across shallow timescales where there is substantial estimation error in individual gene trees.

A new species of Chromis damselfish from the tropical western Atlantic (Teleostei, Pomacentridae)

Initially described in 1882, Chromisenchrysurus, the Yellowtail Reeffish, was redescribed in 1982 to account for an observed color morph that possesses a white tail instead of a yellow one, but morphological and geographic boundaries between the two color morphs were not well understood. Taking advantage of newly collected material from submersible studies of deep reefs and photographs from rebreather dives, this study sought to determine whether the white-tailed Chromis is actually a color morph of Chromisenchrysurus or a distinct species. Phylogenetic analyses of mitochondrial genes cytochrome b and cytochrome c oxidase subunit I separated Chromisenchrysurus and the white-tailed Chromis into two reciprocally monophyletic clades. A principal component analysis based on 27 morphological characters separated the two groups into clusters that correspond with caudal-fin coloration, which was either known or presumed based on the specimen’s collection site according to biogeographic data on species boundaries in the Greater Caribbean. Genetic, morphological, and biogeographic data all indicate that the white-tailed Chromis is a distinct species, herein described as Chromisvanbebberaesp. nov. The discovery of a new species within a conspicuous group such as damselfishes in a well-studied region of the world highlights the importance of deep-reef exploration in documenting undiscovered biodiversity.