Although attempts to understand Central American freshwater fish provincialism date to the 1960s, early efforts lacked the wealth of distributional data now available. Biogeographic work on Central American freshwater fishes has been largely descriptive and regional, and lacked a broader synthesis. Here we use parsimony analysis of endemicity (PAE) to elucidate faunistic relationships between major drainages and to delineate areas of endemism. We then perform a Brooks parsimony analysis (BPA) on the resulting areas. The PAE recovered a primary division between four Pacific and six Atlantic slope areas of endemism. In contrast, the BPA recovered two Central American geographic clades, one sharing a history with North America and the other with South America. Fish diversity is uneven across Central America, with greater diversity in areas adjacent to the more species‐rich regions of North and South America. In northern and nuclear Central America, the paucity of ostariophysan freshwater fishes such as catfishes and characins (groups that dominate adjacent regions) contrasts with high species richness of poeciliids and cichlids. Results of this study are consistent with Myer's hypothesis that poeciliids and cichlids dispersed to Northern or Nuclear Middle America early in the Cenozoic, long before the Plio‐Pleistocene rise of the Isthmus of Panama.

The contrasting distribution of species diversity across the major lineages of cichlids makes them an ideal group for investigating macroevolutionary processes. In this study, we investigate whether different rates of diversification may explain the disparity in species richness across cichlid lineages globally. We present the most taxonomically robust time-calibrated hypothesis of cichlid evolutionary relationships to date. We then utilize this temporal framework to investigate whether both species-rich and depauperate lineages are associated with rapid shifts in diversification rates and if exceptional species richness can be explained by clade age alone. A single significant rapid rate shift increase is detected within the evolutionary history of the African subfamily Pseudocrenilabrinae, which includes the haplochromins of the East African Great Lakes. Several lineages from the subfamilies Pseudocrenilabrinae (Australotilapiini, Oreochromini) and Cichlinae (Heroini) exhibit exceptional species richness given their clade age, a net rate of diversification, and relative rates of extinction, indicating that clade age alone is not a sufficient explanation for their increased diversity. Our results indicate that the Neotropical Cichlinae includes lineages that have not experienced a significant rapid burst in diversification when compared to certain African lineages (rift lake). Neotropical cichlids have remained comparatively understudied with regard to macroevolutionary patterns relative to African lineages, and our results indicate that of Neotropical lineages, the tribe Heroini may have an elevated rate of diversification in contrast to other Neotropical cichlids. These findings provide insight into our understanding of the diversification patterns across taxonomically disparate lineages in this diverse clade of freshwater fishes and one of the most species-rich families of vertebrates.

Ostariophysi is a superorder of bony fishes including more than 10,300 species in 1100 genera and 70 families. This superorder is traditionally divided into five major groups (orders): Gonorynchiformes (milkfishes and sandfishes), Cypriniformes (carps and minnows), Characiformes (tetras and their allies), Siluriformes (catfishes), and Gymnotiformes (electric knifefishes). Unambiguous resolution of the relationships among these lineages remains elusive, with previous molecular and morphological analyses failing to produce a consensus phylogeny. In this study, we use over 350 ultraconserved element (UCEs) loci comprising 5 million base pairs collected across 35 representative ostariophysan species to compile one of the most data-rich phylogenies of fishes to date. We use these data to infer higher level (interordinal) relationships among ostariophysan fishes, focusing on the monophyly of the Characiformes-one of the most contentiously debated groups in fish systematics. As with most previous molecular studies, we recover a non-monophyletic Characiformes with the two monophyletic suborders, Citharinoidei and Characoidei, more closely related to other ostariophysan clades than to each other. We also explore incongruence between results from different UCE data sets, issues of orthology, and the use of morphological characters in combination with our molecular data. [Conserved sequence; ichthyology; massively parallel sequencing; morphology; next-generation sequencing; UCEs.].

Phylogeographic inference has typically relied on analyses of data from one or a few genes to provide estimates of demography and population histories. While much has been learned from these studies, all phylogeographic analysis is conditioned on the data, and thus, inferences derived from data that represent a small sample of the genome are unavoidably tenuous. Here, we demonstrate one approach for moving beyond classic phylogeographic research. We use sequence capture probes and Illumina sequencing to generate data from >400 loci in order to infer the phylogeographic history of Salix melanopsis, a riparian willow with a disjunct distribution in coastal and the inland Pacific Northwest. We evaluate a priori phylogeographic hypotheses using coalescent models for parameter estimation, and the results support earlier findings that identified post-Pleistocene dispersal as the cause of the disjunction in S. melanopsis. We also conduct a series of model selection exercises using IMa2, Migrate-n and ∂a∂i. The resulting ranking of models indicates that refugial dynamics were complex, with multiple regions in the inland regions serving as the source for postglacial colonization. Our results demonstrate that new sources of data and new approaches to data analysis can rejuvenate phylogeographic research by allowing for the identification of complex models that enable researchers to both identify and estimate the most relevant parameters for a given system.

Aim The mountain mullet, Agonostomus monticola, is a diadromous fish widespread throughout Middle America, occurring in rivers along the Atlantic and Pacific slopes, as well as in the West Indies. Based on the disjunct distribution of this species, it has been hypothesized that this fish may represent more than one taxon. The purpose of this study was to conduct a robust phylogeographical analysis of A. monticola across its range, using mitochondrial and nuclear markers. We aimed to investigate the potential for cryptic diversity and the time‐scale of divergence in an effort to elucidate biogeographical episodes within Middle America in relation to the evolutionary history of Agonostomus monticola. Location North and Middle America, including the West Indies. Methods Mitochondrial and nuclear sequence data (cyt b, S7‐1) from individuals throughout the range of the species were analysed phylogenetically using maximum‐likelihood methodology. The oldest known fossil mullet was used as a calibration to investigate divergence times for clades within A. monticola. Results Results indicate four distinct lineages within the known range of A. monticola that largely correspond to oceanic basins (Caribbean, Gulf of Mexico, Pacific‐A, Pacific‐B). Divergence time estimates indicate early to mid‐Miocene divergences for all four A. monticola clades, with Oligocene to Miocene divergences of internal nodes. Main conclusions These findings are congruent with geological hypotheses regarding movement of the Chortís block, as well as recent studies on the age of beginning emergence of the Panama Arc.

No abstract

In recent years great strides have been made for improving our understanding of the evolutionary relationships among neotropical cichlids, particularly within the clade Heroini and its crown clade the herichthyins. Most phylogenetic studies have largely converged on congruent topologies for relationships among species and major lineages within the herichthyins. One major aspect missing from previous studies of these cichlids is a formal taxonomic revision, including the redefining of genera. Based on analysis of 52 species and three mitochondrial and two nuclear loci, we generate a Bayesian phylogeny for the herichthyin cichlids, and formally revise the taxonomy for genera within this clade using morphological features. Eight new genera are recognized and a key to all 16 genera of herichthyin cichlids is also presented.Key words: cichlid, revision, Mexico, Central America, morphology ResúmenGrandes pasos se han dado en años recientes en la mejora de nuestro conocimiento de las relaciones evolutivas entre ciclidos Neotropicales, particularmente dentro del clado Heroini. En el clado corona de Heroini están los herichthyins. Los estudios filogenéticos más recientes, han coincidido ampliamente con topologías congruentes para definir las relaciones entre especies y linajes mayores en este clado. La falta de una revisión taxonómica formal de estos ciclidos, es un gran vacío que han dejado estudios anteriores, incluyendo la redefinición de géneros. Basados en un muestreo taxonómico completo y un set de datos molecular casi-completo, nosotros generamos una filogenia para el grupo de ciclidos conocido como los herichthyins, y revisamos formalmente la taxonomía de cada género en este clado usando caracteres morfológi-cos. Una clave para los 16 géneros de ciclidos herichthyinos es también presentada.

Aim: The processes that generate biodiversity occur at finer scales than are often studied, particularly in freshwater systems of the northern Neotropics. We investigate whether fine-scale biogeographic patterns are present within the larger Grijalva-Usumacinta Area of Endemism (AoE)-a region in Middle America where nearly 60% of freshwater fishes are endemic-and if present-day river basins are single historical units. Location: Northern Central America and southern Mexico.