A taxonomic revision of Cheilodactylidae and Latridae (Centrarchiformes: Cirrhitoidei) using morphological and genomic characters

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

The molecular biogeography of the Indo‐Pacific: Testing hypotheses with multispecies genetic patterns

Aim: To test hypothesized biogeographic partitions of the tropical Indo‐Pacific Ocean with phylogeographic data from 56 taxa, and to evaluate the strength and nature of barriers emerging from this test. Location: The Indo‐Pacific Ocean. Time period: Pliocene through the Holocene. Major taxa studied: Fifty‐six marine species. Methods: We tested eight biogeographic hypotheses for partitioning of the Indo‐Pacific using a novel modification to analysis of molecular variance. Putative barriers to gene flow emerging from this analysis were evaluated for pairwise ΦST, and these ΦST distributions were compared to distributions from randomized datasets and simple coalescent simulations of vicariance arising from the Last Glacial Maximum. We then weighed the relative contribution of distance versus environmental or geographic barriers to pairwise ΦST with a distance‐based redundancy analysis (dbRDA). Results: We observed a diversity of outcomes, although the majority of species fit a few broad biogeographic regions. Repeated coalescent simulation of a simple vicariance model yielded a wide distribution of pairwise ΦST that was very similar to empirical distributions observed across five putative barriers to gene flow. Three of these barriers had median ΦSTthat were significantly larger than random expectation. Only 21 of 52 species analysed with dbRDA rejected the null model. Among these, 15 had overwater distance as a significant predictor of pairwise ΦST, while 11 were significant for geographic or environmental barriers other than distance. Main conclusions: Although there is support for three previously described barriers, phylogeographic discordance in the Indo‐Pacific Ocean indicates incongruity between processes shaping the distributions of diversity at the species and population levels. Among the many possible causes of this incongruity, genetic drift provides the most compelling explanation: given massive effective population sizes of Indo‐Pacific species, even hard vicariance for tens of thousands of years can yield ΦST values that range from 0 to nearly 0.5

Phylogeography of Eleotris fusca (Teleostei: Gobioidei: Eleotridae) in the Indo-Pacific area reveals a cryptic species in the Indian Ocean

International audienceIndo-Pacific insular freshwater systems are mainly dominated by amphidromous species. Eleotris fusca is a widespread one, its life cycle is characterised by a marine pelagic larval phase allowing the species to disperse in the ocean and then to recruit to remote island rivers. In the present study, the population structure of E. fusca over its Indo-Pacific distribution range (Western Indian Ocean to French Polynesia, Pacific Ocean) was evaluated. We analysed a section of mitochondrial COI of 557 individuals sampled from 28 islands to visualise the population structure. Haplotypes diversity (Hd) was between 0.458 and 1 and, nucleotide diversity (π) was between 0.001 and 0.02. Two distinct genetic groups appeared, one in the Indian Ocean and the other in the Pacific Ocean (FST mean = 0.901; 5.2% average divergence). Given these results, complete mitogenomes (mtDNA) were sequenced and combined with the nuclear Rhodopsin (Rh) gene for a subset of individuals. The two phylogenetic trees based on each analysis showed the same genetic pattern: two different groups belonging to the Indian and the Pacific oceans (6.6 and 1.6% of divergence for mtDNA and Rh gene respectively), which supported species level differentiation. These analyses revealed the presence of two sister species confounded until present under the name of Eleotris fusca. One of them is cryptic and endemic of the Indian Ocean and the other one is the true E. fusca, which keeps, nevertheless, its status of widespread species