Allopatric Distribution Research Articles

Topology Testing and Demographic Modeling Illuminate a Novel Speciation Pathway in the Greater Caribbean Sea Following the Formation of the Isthmus of Panama.

Recent genomic analyses have highlighted the prevalence of speciation with gene flow in many taxa and have underscored the importance of accounting for these reticulate evolutionary processes when constructing species trees and generating parameter estimates. This is especially important for deepening our understanding of speciation in the sea where fast moving ocean currents, expanses of deep water, and periodic episodes of sea level rise and fall act as soft and temporary allopatric barriers that facilitate both divergence and secondary contact. Under these conditions, gene flow is not expected to cease completely while contemporary distributions are expected to differ from historical ones. Here we conduct range-wide sampling for Pederson's cleaner shrimp (Ancylomenes pedersoni), a species complex from the Greater Caribbean that contains three clearly delimited mitochondrial lineages with both allopatric and sympatric distributions. Using mtDNA barcodes and a genomic ddRADseq approach, we combine classic phylogenetic analyses with extensive topology testing and demographic modeling (10 site frequency replicates x 45 evolutionary models x 50 model simulations/replicate = 22,500 simulations) to test species boundaries and reconstruct the evolutionary history of what was expected to be a simple case study. Instead, our results indicate a history of allopatric divergence, secondary contact, introgression, and endemic hybrid speciation that we hypothesize was driven by the final closure of the Isthmus of Panama and the strengthening of the Gulf Stream Current ~3.5 million years ago. The history of this species complex recovered by model-based methods that allow reticulation differs from that recovered by standard phylogenetic analyses and is unexpected given contemporary distributions. The geologically and biologically meaningful insights gained by our model selection analyses illuminate what is likely a novel pathway of species formation not previously documented that resulted from one of the most biogeographically significant events in Earth's history.

Four-toed sengi (Petrodromus tetradactylus, Afrotheria, Mammalia) museomics reveals a crucial role of East African forests in macroscelidean diversification

Abstract Sengis (Macroscelidea) are members of the Afroinsectivora, a group of mammals belonging to the supercohort Afrotheria. Sengis’ low population densities and their distribution, which includes politically unstable regions with ongoing armed conflicts, hinder contemporary sampling of comprehensive datasets. We overcome this obstacle for the species Petrodromus tetradactylus, one of the most widely distributed sengi species, by utilizing 44 historical museum samples from multiple natural history museums. These historical samples were combined with newly generated or published data of 11 modern samples, thus creating a dataset of 55 P. tetradactylus individuals covering most of the species’ distribution. Phylogenetic reconstruction with 11 nuclear loci in conjunction with mostly complete mitochondrial genomes reveals multiple deeply divergent and formerly unknown lineages within this monotypic genus, highlighting the need for a taxonomic revision. Furthermore, we can show that the assumed allopatric distribution of P. tetradactylus in Central Africa most likely represents a sampling artifact. Biogeographic character mapping indicates that the African forest system and its dynamics through climate fluctuations shaped the evolutionary and biogeographic history of this taxon. We show that lineages within Petrodromus that were able to adapt to dryer woodland ecosystems are much more widely distributed than lineages restricted to moist forest systems. The evolution and radiation of the four-toed sengi (P. tetradactylus) mirrors the patterns of its distant relative, the giant sengis (Rhynchocyon) in both ecotype variation and overall distribution, implying a significant influence of climate and landscape features in shaping diversification.

Differentiation in Leaf Functional Traits and Driving Factors of the Allopatric Distribution of Tetraploid and Octaploid Buddleja macrostachya in the Sino-Himalayan Region

Leaf functional traits reflect species’ adaptive strategies and habitat requirements. Examining intra-specific variations and their underlying drivers can aid in comprehending species differentiation and adaptation. Here, we investigated the leaf functional traits of Buddleja macrostachya tetraploids and octaploids across 18 sites in the Sino-Himalayan region. The habitat environmental variables were also recorded. In this study, leaf functional traits showed a considerable differentiation in both tetraploid and octaploid B. macrostachya. Redundancy analysis (RDA) revealed that the octaploid cytotypes displayed higher specific leaf area, leaf total nitrogen and phosphorus concentrations, water-use efficiency, and light-use efficiency in contrast to the tetraploid plants. These functional leaf traits exhibited different plasticity levels in both taxa. A positive link was found between habitat altitude and soil total P concentration and the geographic distribution of the B. macrostachya complex, using RDA and Pearson’s correlation. Our findings suggest that both tetraploid and octaploid B. macrostachya exhibited divergent ecological strategies, conservative and acquisitive strategies, respectively. The ecological adaptability of species within the B. macrostachya complex is enhanced by the combination of divergent ecological strategies and high phenotypic plasticity of distinct key ecological traits. Furthermore, abiotic environmental factors influenced the allopatric geographic distribution pattern of the B. macrostachya complex in the Sino-Himalayan region.

Ecological Niche Differentiation and Response to Climate Change of the African Endemic Family Myrothamnaceae.

Studying the ecological niches of species and their responses to climate change can provide better conservation strategies for these species. Myrothamnaceae is endemic to Africa, comprising only two species that belong to Myrothamnus (M. flabellifolius and M. moschatus). These closely related species exhibit allopatric distributions, positioning them as ideal materials for studying the species ecological adaptation. This study explores the ecological niche differentiation between M. flabellifolius and M. moschatus and their response capabilities to future climate change. The results indicate that M. flabellifolius and M. moschatus have undergone niche differentiation. The main drivers of niche differences are the minimum temperature of the coldest month (Bio6) for M. flabellifolius, precipitation of the driest month (Bio14), and precipitation of the coldest quarter (Bio19) for M. moschatus. M. flabellifolius demonstrated a stronger adaptation to environments characterized by lower precipitation, relatively lower temperatures, and greater annual temperature variations compared to M. moschatus. Under future climate scenarios (SSP5-8.5, 2081-2100 years), the results show that approximately 85% of the total suitable habitat for M. flabellifolius will be lost, with an 85% reduction in high-suitability areas and almost complete loss of the original mid-low suitability areas. Concurrently, about 29% of the total suitable habitat for M. moschatus will be lost, with a 34% reduction in high suitability areas and roughly 60% of the original mid-low suitability areas becoming unsuitable. This suggests that M. flabellifolius will face greater threats under future climate change. This study contributes novel insight into niche differentiation in Myrothamnaceae and provides useful information for the conservation of this distinctive African lineage.

The South American genus Cnemalobus (Coleoptera: Carabidae: Cnemalobini): phylogeny and biogeographic analysis with the description of four new species from extra-Andean Patagonian mountains.

The carabid beetle Cnemalobus Guérin-Ménéville, 1838 inhabits high- and lowland grasslands of southern South America. The highest diversity is found in the Patagonian Steppe, where distribution patterns are associated with latitude and elevation. Northern Patagonia, a large volcanic region with a complex geoclimatic history, exhibits elevated grades of endemism. However, a great deal remains unknown regarding diversification and biogeographical patterns for most of the endemic groups. We describe new Cnemalobus species restricted to isolated volcanoes from these extra-Andean mountain systems. We assess the phylogenetic relationships by updating the phylogeny of the genus and conduct a Bayesian binary Markov chain-Monte Carlo (MCMC) analysis on the resulting phylogenetic tree to discuss the biogeographical distribution patterns. We also provide a taxonomic key to all currently known species of Cnemalobus from the Patagonian Steppe. Our phylogenetic analysis supports the monophyly of the new species Cnemalobus tromen sp. nov., Cnemalobus silviae sp. nov., Cnemalobus aucamahuida sp. nov. and Cnemalobus domuyo sp. nov. grouped with C. diamante and C. nevado , referred to as the 'Extra-Andean' mountain lineage. Biogeographical analysis recognises vicariant events as the most plausible explanation for the allopatric distributions of the new species. We hypothesise that these vicariant events could be related to climatic barriers that likely promoted speciation processes by generating geographical isolation in ancestral populations. Our findings contribute significantly to the biogeographical understanding of the Patagonian volcanic region, prompting new inquiries to unravel the speciation processes of the endemic biota in extra-Andean mountain systems. ZooBank: urn:lsid:zoobank.org:pub:6A7585E8-5006-45BC-A1A3-F874F18A6049.

Sclerocactus dawsoniae (Cactaceae), a New Species from Western Colorado, U.S.A.

Sclerocactus dawsoniae McGlaughlin & Naibauer (Cactaceae), a new species from western Colorado, is described. Sclerocactus dawsoniae is segregated from S. glaucus (K. Schum.) L. D. Benson, differing by having a smaller overall size, fewer spines per areole, an allopatric distribution, and substantial genetic differentiation.

Systematic revision of the eastern Queensland land snail genus Figuladra Köhler and Bouchet, 2020 based on mitochondrial phylogenetics and comparative morpho-anatomy (Eupulmonata, Camaenidae)

ABSTRACT The current study revises the systematic taxonomy of Figuladra, a genus of camaenid land snails endemic to eastern Queensland, based on the investigation of many recently collected ethanol-preserved samples as well as historic museum material, including types. We employed comparative analyses to investigate the variation in morphological features (shell, penial anatomy) and performed phylogenetic analyses of mitochondrial 16S rDNA sequences to test species hypotheses. Phylogenetic analyses recovered three principal mitochondrial clades, one occurring in mid-east Queensland, one in south-east Queensland, and another in the upland areas of south-east Queensland. We recognise altogether 15 accepted species, including four that are newly described herein (i.e., Figuladra finlaysoni sp. nov., F. robertirwini sp. nov., F. bromileyorum sp. nov. and F. vidulus sp. nov.). The status of 11 previously described species has been assessed and revised diagnoses are provided for each of these. Species of the south-east Queensland clade revealed comparatively low levels of genetic and morphological differentiation and may represent examples of more recent, conceivably ongoing, speciation. Figuladra species have allopatric distributions with their ranges being separated by altitudinal or riverine barriers. Particularly the St Lawrence Gap dry corridor has been identified as a major biogeographic barrier separating two principal clades of Figuladra.

Comparative analysis of four iridoids between Gentiana rigescens and G. cephalantha from the sympatric and allopatric distributions

Gentiana rigescens Franch. Ex Hemsl. is listed as an original species of Gentianae radix et rhizoma which is also an endangered plant in Gentianaceae. G. cephalantha Franch. Ex Hemsl., a sister species to G. rigescens, is usually used as a substitute of this endangered species in folk because of its similar morphologic features and abundant resources. To investigate reasonability of the replacement, four iridoids, namely gentiopicroside, swertiamarin, sweroside, and amarogentin were determined based on HPLC method and compared between G. rigescens and G. cephalantha from the sympatric and allopatric distributions. Total contents of the four iridoids were 9.05%–9.77% with an average value of 9.45% for G. rigescens, and 9.01%–12.73% with an average value of 11.20% for G. cephalantha, respectively. The results showed that contents of the iridoids in G. cephalantha was significantly higher than those in G. rigescens (P < 0.001), including the samples from the sympatric distribution. Meanwhile, samples from the middle altitude possessed higher content than those from the low and high altitudes. Moreover, hierarchical cluster analysis revealed well regularity of the iridoids content between G. rigescens and G. cephalantha, except the sample Gr3 which indicated that there were obviously genetic differences between the two species. This study could provide scientific evidence on substituting for G. rigescens with G. cephalantha based on contents of the active components which would further expand medicinal resources and be beneficial to conservation of G. rigescens.

Slow and steady saves the race: molecular and morphological analysis of three new cryptic species of Iberus land snails from the Iberian Peninsula

The Iberian Peninsula constitutes a diversity hotspot with a high number of endemisms, where the land snail genus Iberus is likely the best example. Despite this, its species diversity is still debated as it holds several cryptic species. In the present paper, we use molecular evidence (mitochondrial DNA cytochrome oxidase subunit I) to clarify the position of I. ortizi and three new cryptic species that are described herein: I. giennensis, I. axarciensis and I. antikarianus spp. nov. For this, we sampled 281 sampling points to delimitate a comprehensive geographic mapping of these species. Moreover, we carried out a comprehensive morphometric analysis based on 3205 shells. Our findings show that, morphologically, the three described species overlap in the form of their shells, their morphologies being very similar to other close species with nearby distributions (I. ortizi, I. angustatus and I. marmoratus loxanus). Still, all these species are well-defined by genetic distances, but display allopatric distributions, suggesting that they evolved by allopatric speciation as a consequence of biogeographic isolation. Hence, our findings show insights into the evolution of land snails in southeastern Spain, with implications for their conservation, given that our exhaustive sampling shows that the three species described here have very limited distribution ranges, especially I. antikarianus sp. nov. Our study, moreover, implies an integrated approach to the study of the evolution of land snails, including the sampling of the complete geographic area occupied by the genus, genetic analysis to delimit the actual species range, as well as morphometric analyses to understand the phenotypic differentiation and adaptations of the three new species.

Molecular data and morphological characters clarify the taxonomic status of Pintara heringi pieridoides (Liu & Gu, 1994) (Hesperiidae, Pyrginae).

We found Albiphasma heringi (Mell, 1922) and A. pieridoides (Liu & Gu, 1994) to be conspecific by the 658 bp COI gene sequences and male genitalia characters. Considering the distinguishable wing patterns and allopatric distribution of the two taxa, we treat pieridoides as a subspecies of heringi. Therefore, the genus Albiphasma Huang, Chiba, Wang and Fan, 2016, which was established for heringi and pieridoides, becomes monotypic, and in light of morphological similarities and close genetic distance between heringi and Pintara bowringi (Joicey & Talbot, 1921), we propose its synonymy with Pintara Evans, 1932. The adults and male genitalia of both P. heringi heringi (Mell, 1922) and P. heringi pieridoides (Liu & Gu, 1994) are illustrated.

Biogeography, speciation and niche evolution of doraditos (Aves: Pseudocolopteryx)

AbstractEcological and geographical factors shape the current distribution of species. Analysing their interplay in a phylogenetic framework is key to understand the historical processes that have shaped the evolution of a group. Here, we modelled the ecological niches and geographic distributions of the five species of doraditos (Pseudocolopteryx spp.) to study their biogeographic histories, niche evolution and speciation process in a phylogenetic framework. Our potential distribution models uncovered novel range‐wide distributional patterns and seasonal movements in the doraditos, where four species are migratory with distinct breeding and non‐breeding distributions, and one (P. sclateri) exhibits a complex spatiotemporal distribution indicating nomadism. Ecological niche pairwise comparisons showed that none of the doraditos have equivalent niches and that niche differences are due to species‐specific habitat preferences. Phylogenetically weighted geographical and ecological analyses showed patterns of allopatric speciation and niche lability in the evolution of doraditos. The divergence of P. sclateri seems tied to its tropical‐to‐temperate wetland specialization. The montane P. acutipennis expanded to human‐modified lowlands following speciation, highlighting the need to control for post‐speciational changes in ecological niche comparisons as done here. In turn, P. dinelliana, P. citreola and P. flaviventris showed essentially allopatric breeding distributions, as a product of environmentally mediated divergence during their speciation processes. The distribution and migration data of the recently diverged cryptic sister species P. citreola and P. flaviventris are consistent with two possible speciation scenarios: peripatric speciation and migration dosing speciation.

Microgeographic speciation in a complex of Anatolian bush crickets facilitated by fast evolution of reproductive isolation.

Identifying the drivers of microgeographic speciation (i.e., speciation over small, local geographic scales) is key to understand the origin of speciose groups. Here, we use genomic data to infer the demographic processes underlying diversification in Poecilimon luschani (Orthoptera: Tettigoniidae), a species complex belonging to the most diverse genus of bush crickets from the Mediterranean region (>170 taxa) that comprises three recognized subspecies with small allopatric distributions in the topographically complex Teke Peninsula, southwestern Anatolia. Phylogenomic reconstructions that include all other taxa within the species group confirmed that subspecies of P. luschani originated from a common ancestor during the Pleistocene, supporting recent (<1 Ma) diversification within a small geographical area (ca. 120 × 80 km). Genetic clustering analyses corroborated the distinctiveness of each subspecies and the cohesiveness of their respective populations, with abrupt genetic discontinuities coinciding with contemporary range boundaries. Indeed, our analyses uncovered the presence of two sympatric cryptic sister lineages that diverged <300 ka ago and do not admix despite being co-distributed. Collectively, these results support that all lineages within the complex represent independently evolving entities corresponding to full-fledged species. Statistical evaluation of alternative models of speciation strongly supports a scenario of divergence in isolation followed by a period of limited gene flow during the last glacial period, when all lineages experienced marked expansions according to demographic reconstructions. Our study exemplifies how localized allopatric divergence and fast evolution of reproductive isolation can promote microgeographic speciation and explain the high rates of endemism characterizing biodiversity hotspots.

Molecular population genetics and phylogeographic studies of Ligia exotica and Ligia cinerascens in East Asia

IntroductionSea slater, in the genus Ligia, is widespread in rocky shore habitats, and the taxon is easily isolated due to its limited dispersal capacity. Therefore, most Ligia species exhibit an allopatric distribution, but Ligia exotica and L. cinerascens exhibit an overlapping distribution distribution in East Asia. Previous studies on both species have confirmed the existence of highly divergent lineages based on 16S rRNA.MethodsIn the present study, 282 Ligia individuals were collected at ten, three, and three sites in South Korea, Japan, and Vietnam, respectively, and 41 haplotypes were observed based on 16S rRNA.Results and discussionThe results of phylogeny, phylogenetic network, and TCS network, Principal Coordinates Analysis, and four Molecular Species Delimitation Analyses revealed that six genetic lineages including L. cinerascens, Lineages N and S of L. exotica, Ligia sp. 1, sp.2 and sp.3 were present. The three genetic lineages, including L. cinerascens, Lineage N of L. exotica, and Lineage S of L. exotica, were also identified in the phylogeny based on a nuclear gene of the sodium–potassium ATPase α-subunit (Nak). Phylogeographic analysis revealed that L. cinerascens and Lineage N of L. exotica were distributed overlappingly in South Korea, Japan, and the northern region of China. Generally, the two lineages of L. exotica were distributed allopatrically, which was more evident along the coastline of mainland China than that of Japan. The results of time-calibrated phylogeny suggested that the speciation events of Ligia species might be associated with Japanese mainland formation from Oligocene to Miocene (approximately 30-5 million years ago, Mya). The results of the present study provide insights that could facilitate the understanding of the evolutionary history of Ligia, tracking of geological processes, and evolutionary effects of palaeogeographical events at the population level.

Taxonomic studies in Colombian Picramniaceae (Picramniales): new species of Aenigmanu, Nothotalisia and Picramnia from the Pacific and Magdalena Valley regions

Three new species of Picramniaceae from Colombia are described and illustrated; Aenigmanu chococola from the Pacific region is the second species of the previously monotypic genus, known only from the Amazon region. In addition to its allopatric distribution, the new species is mainly recognisable by its wide leaf blades, which are basally convex and commonly apically emarginate at the very tip, and long bracts on the pistillate inflorescences. Nothotalisia karsticola and Picramnia vinacea are from karst areas in the Magdalena Valley; the former is mainly recognisable by its long inflorescences, pistillate inflorescences in racemes, staminate flowers with long petals and anthers apically mucronate, whereas the latter is mainly recognisable by its racemose inflorescences in both staminate and pistillate plants, pedicel length in staminate flowers, filaments shorter than the petals and glabrous fruits. We also include notes about their taxonomic affinities, habitat, geographical distribution, phenology, etymology and conservation status. A key for species of Nothotalisia is provided.

Gelidiella papillosa sp. nov. (Gelidiellaceae, Rhodophyta) from Veracruz, Mexico, in the context of the worldwide distribution of G. acerosa

Abstract Gelidiella acerosa is a widely distributed species, with type locality in Yemen, whose morphology has been characterized by decumbent axes from which numerous abundantly branched erect axes emerge, pectinate, alternate or radial. Recent phylogenetic studies have revealed the presence of genetically independent groups throughout its distribution range. However, these groups cannot be described as independent since there are no sequences from the type locality that allow us to establish the genetic group to which the true G. acerosa belongs, generating a complex of cryptic species. In the present study, from COI-5P and rbcL sequence data, we detected six genetically differentiated groups, one of which is represented only by specimens from the Western Atlantic region. Given the allopatric pattern, it is possible to describe the Atlantic group as an independent species of the cryptic complex in the Indo-Pacific. Gelidiella papillosa sp. nov. shares several morphological features with other specimens previously identified as G. acerosa in other countries, like the appearance of the thallus, branching patterns, the presence of multiple superficial hairs on the branches or cell measurements. However, these characters have not been evaluated in detail among the different genetic groups within Gelidiella acerosa, consequently, G. papillosa can be supported only by its genetic independence and allopatric distribution.

Two new species of terrestrial frogs of the Pristimantisgladiator complex (Anura, Strabomantidae) from the Ecuadorian Andes, with insights on their biogeography and skull morphology.

The explosive diversity of rainfrogs (Pristimantis spp) reaches its highest levels in the mountains of the Tropical Andes, with remarkable cryptic species mainly in unexplored areas of Ecuador. Based on phylogenetics, morphometric traits, skull osteology and bioacoustics, we describe two new species of Pristimantis, previously confused with Pristimantisgladiator, that belong to the subgenus Trachyphrynus traditionally known as the Pristimantismyersi species group. The two new taxa are closely related, but have allopatric distributions. We discuss the importance of the Quijos and Pastaza River valleys in the diversification along Amazonian slopes of the Ecuadorian Andes.

Niche evolution and diversification in Middle Eastern stream salamanders (Paradactylodon): vulnerability to future climate change

Abstract The relict genus Paradactylodon is narrowly distributed in temperate forests throughout the Middle East region, including P. mustersi in Afghanistan, P. persicus, and P. gorganensis in northwestern and northeastern Iran. Recent phylogenetic analyses suggest that the Iranian Paradactylodon populations may belong to a single species, P. persicus. In this study, we addressed how climatic niche conservatism and/or niche divergence may have affected the evolution of all Paradactylodon species using ecological niche models and multivariate niche analyses to identify niche overlap and assess equivalency and similarity tests. We also used an ensemble of ten algorithms to predict Paradactylodon species distributions for recent (1970-2000) and future (2081-2100) climate conditions. The results show that future climate change may cause the loss of 80 to 97% of these species’ suitable habitat, especially at lower elevations. The niche divergence hypothesis was supported by the results of niche equivalency tests on P. persicus vs. P. gorganensis (and vice versa) with moderate overlap (D = 0.23, I = 0.41) and P. persicus vs. P. mustersi (and vice versa) with little overlap (D = 0.05, I = 0.06). Meanwhile, the niche similarity test for the niche conservatism hypothesis revealed significant results for P. persicus vs. P. gorganensis, P. mustersi vs. P. persicus, and P. persicus + P. gorganensis (as a single species) vs. P. mustersi. Due to these complex evolutionary ecological patterns and allopatric distributions, we recommend that P. gorganensis be considered a valid subspecies.

Molecular and acoustic evidence support the species status of Anthus rubescens rubescens and Anthus [rubescens] japonicus (Passeriformes: Motacillidae).

The Buff-bellied Pipit Anthus rubescens comprises two allopatric subspecies groups: A. r. rubescens and A. r. alticola in North America and A. [r.] japonicus in north-east Asia. Despite their great morphological resemblance in breeding plumage, most individuals can be assigned to one or the other subspecies group in non-breeding plumage. Allopatric distributions, morphological differentiation and previously reported molecular divergence suggested the need for additional taxonomic study to assess the rank of these two populations. To resolve the taxonomy of the Buff-bellied Pipit species complex we analysed i) two mitochondrial DNA (mtDNA) loci and ii) nine bioacoustic parameters across 69 sound recordings (338 flight calls) recovered from public databases using principal component analysis and Euclidean distance measures. By comparing our mtDNA and call divergence measures with similar values measured between long-recognised species pairs of the genus, we show that the level of mitochondrial and acoustic divergence between the two Buff-bellied Pipit subspecies groups is typical of species-level divergence in the genus Anthus. Therefore, we recommend splitting the Buff-bellied Pipit species complex into two species: Anthus rubescens (American Pipit) and Anthus japonicus (Siberian Pipit). Our results also suggest that the Water Pipit A. spinoletta deserves taxonomic reassessment as its lineages are highly divergent in acoustics and mtDNA, while mtDNA relationships suggest paraphyly relative to the Rock Pipit A. petrosus. Our work highlights the crucial importance of integrative approaches in taxonomy and the usefulness of bioacoustics in studying cryptic diversity.

Past riverine connectivity effects in population structure and distribution of an endemic freshwater fish from northeastern Brazilian rivers: Phylogeographic, taxonomic, and conservation implications

Abstract The coastal basins of eastern Brazil are influenced by geomorphologic and climatic changes that caused river captures and temporary paleo‐connections due to sea‐level oscillations. These two events can lead to isolation and connection among coastal rivers and have a strong influence on the distribution of freshwater fishes in this region. Characidium bahiense is a small fish species with a wide distribution, ranging from the coastal basins of the North Group of the Northeastern Mata Atlântica ecoregion to São Francisco and Parnaíba ecoregions. The allopatric distribution of C. bahiense associated with the possible morphological and molecular variations among geographically isolated populations stimulated this study. Here, we use an integrative approach, encompassing morphological and mitonuclear data, and paleodrainage reconstruction to better understand the evolutionary history of C. bahiense and to test the putative effects of the current configuration of basins and historical drainage rearrangements on the genetic structuring of the species. Our mitochondrial data show that C. bahiense is not a monophyletic species since the specimens from one locality are more closely related to Characidium cf. lagosantense than to other populations of C. bahiense. Multilocus analyses, however, recovered the monophyly of this species, although the molecular delimitation method considers each mitochondrial DNA lineages as a separated species. Overall, the morphological data revealed some intraspecific overlapping variation, suggesting that all specimens of C. bahiense are conspecific. Molecular analyses combined with geomorphological information suggest that the current distribution of C. bahiense is the result of climate change that directly affected river flow dynamics and recent riverine captures during the Pleistocene. The use of multiple data sources not only provides a more reliable interpretation of the evolutionary history of a species, but can also avoid arbitrary taxonomic decisions. Future phylogeographic studies involving other freshwater fish species with a similar distribution to C. bahiense are necessary to assist in understanding the scenarios presented here.

Phylogenetic revision of whisker-cheeked suckermouth catfishes (Loricariidae: Lasiancistrus) from east of the Andes: five species where once there were two

Abstract We integrated large sample sizes, morphometric and molecular data, and phylogenetic and species delimitation analyses to test the 17-year-old hypothesis that only two species of whisker-cheeked suckermouth catfishes (genus Lasiancistrus) occur in river drainages west of the Andes Mountains. Our results reject this hypothesis, demonstrating that, in addition to the previously recognized Lasiancistrus guacharote from Lake Maracaibo, a Lasiancistrus clade from west of the Sierra de Perijá contains at least four allopatric, genetically differentiated and morphologically distinct lineages. One of these lineages had no previous name associated with it and is described here as the new species Lasiancistrus wiwa. Phylogenetic relationships and geographical distributions of all five trans-Andean lineages are concordant with watershed boundaries and major mountain ranges that form these boundaries, with the following five freshwater basins or regions each containing a single species: Lake Maracaibo (L. guacharote), Rancheria River basin (L. wiwa), Upper and Middle Magdalena River and lower Cauca River basins (Lasiancistrus volcanensis), Upper Cauca River basin (Lasiancistrus caucanus) and Pacific Coastal watersheds between central Colombia and central Panama (Lasiancistrus mayoloi). Evolutionary relationships among these lineages suggest that Andean uplift-mediated vicariance contributed significantly to the cladogenesis and allopatric distributions of these fishes.