Group Of Freshwater Fishes Research Articles

Expansion of vomeronasal receptor genes (OlfC) in the evolution of fright reaction in Ostariophysan fishes

Ostariophysans are the most diverse group of freshwater fishes and feature a pheromone-elicited fright reaction. However, the genetic basis of fright reaction is unclear. Here, we compared vomeronasal type 2 receptor-like (OlfC) genes from fishes having and lacking fright reaction, to provide insight into evolution of pheromonal olfaction in fishes. We found OlfC genes expanded remarkably in ostariophysans having fright reaction compared with fishes lacking fright reaction. Phylogenetic analysis indicates OlfC subfamily 9 expanded specifically in ostariophysans having fright reaction. Principle component and phylogenetic logistic regression analysis partitioned fishes by ecotype (having or lacking fright reaction) and identified OlfC subfamily 9 as being an important factor for fright reaction. Expression levels of expanded OlfC subfamily genes after fright reaction in zebrafish changed more than did genes that had not expanded. Furthermore, evidence of positive selection was found in the expanded OlfC proteins in ostariophysan fishes having fright reaction. These results provide new insight into the genetic basis of fright reaction in ostariophysan fish and will enable future research into the mechanism of action of OlfC proteins.

The Role of Developmental Integration and Historical Contingency in the Origin and Evolution of Cypriniform Trophic Novelties.

While functional morphologists have long studied the evolution of anatomical structures, the origin of morphological novelties has received less attention. When such novelties first originate they must become incorporated into an integrated system to be rendered fully functional. Thus, developmental integration is key at the origin of morphological novelties. However, given enough evolutionary time such integration may be broken, allowing for a division of labor that is facilitated by subsequent decoupling of structures. Cypriniformes represent a diverse group of freshwater fishes characterized by several trophic novelties that include: kinethmoid-mediated premaxillary protrusion, a muscular palatal and post-lingual organ, hypertrophied lower pharyngeal jaws that masticate against the base of the neurocranium, novel pharyngeal musculature controlling movement of the hypertrophied lower pharyngeal jaws, and in a few species an incredibly complex epibranchial organ used to aggregate filtered phytoplankton. Here, we use the wealth of such trophic novelties in different cypriniform fishes to present case studies in which developmental integration allowed for the origin of morphological innovations. As proposed in case studies 1 and 2 trophic innovations may be associated with both morphological and lineage diversification. Alternatively, case studies 3 and 4 represent a situation where ecological niche was expanded but with no concomitant increase in species diversity.

Dietary intake, drinking water ingestion and plasma perfluoroalkyl substances concentration in reproductive aged Chinese women

BackgroundPerfluoroalkyl and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals that are widely used in industrial and consumer products. A growing body of literature suggests that exposure to these chemicals are associated with adverse reproductive outcomes in women. However, the sources of PFAS exposure are often poorly characterized in women of child-bearing age. ObjectivesTo examine the association of plasma PFAS concentrations with dietary intake and drinking water sources in reproductive aged women in Shanghai, one of the high PFAS polluted regions in China. MethodsConcentrations of ten PFAS in plasma samples were measured in 933 women. Information on dietary intake and type of drinking water was collected by questionnaire. We used multivariable linear regression models to assess the association of PFAS concentrations with dietary intake and drinking water. ResultsAfter controlling for potential confounders, a higher frequency of intake of aquatic products (freshwater fish, marine fish, shellfish, shrimp and crab) was positively and significantly associated with concentrations of PFOS, PFOA, PFNA, PFDA, PFUA and PFDoA in 900 reproductive aged women. Intake of freshwater fish showed the strongest association with PFAS. Compared with the lowest intake group of freshwater fish, the intermediate intake group had 8–32% increase in the concentrations of these pollutants; and the highest group had 11–57% increase. Conversely, intake of soy products was associated with lower levels of PFDA, PFUA, PFNA, PFOS, and PFDoA. In addition, compared with women drinking tap water, drinking bottled water was associated with significantly decreases in PFHpA, PFDA, PFOA, PFUA and PFBS blood levels by 9–13% in 905 reproductive aged women. ConclusionsIntake of freshwater fish, marine fish, shrimp and crab was positively associated with plasma PFAS concentrations, while intake of soy products and bottled water was associated with lower PFAS concentrations in the Chinese women of reproductive age.

Phylogenetic relationships of Cypriniformes and plasticity of pharyngeal teeth in the adaptive radiation of cyprinids.

The Cypriniformes comprise approximately 4,200 species accounting for 25% of the diversity of all freshwater fish, which is widely distributed across the world's continents except Antarctica, South America, and Australia. The highest species diversity is found in Southeastern Asia. Despite its remarkable species diversity and broad-scale geographic patterns of distribution, the evolutionary history of this major freshwater fish group remains largely unresolved. To gain insight of the evolutionary history of Cypriniformes, we present a phylogeny of this group using 1 mitochondrial gene and 15 nuclear genes comprising a total of 14,061 bp. Bayesian inference using all gene fragments yielded a well resolved phylogeny, which is mostly consistent with topologies obtained from Maximum Likelihood analyses. Our results further confirmed the monophyly of Cypriniformes and seven constituent subclades including Cyprinidae, Catostomidae, Gyrinocheilidae, Balitoridae, Cobitidae, Nemacheilidae, and Botiidae. Bayesian divergence time analysis indicated that the origin of the Cypriniformes was about 193 Mya during the early Jurassic, coinciding with the onset of the Pangaea breakup. The basal divergence of Cypriniformes is 154 Mya during the late Jurassic. Our findings from molecular divergence and biogeographical analysis indicate the most likely initial geographical range of the ancient Cypriniformes was both East and South Asia (Southeastern area of Mesozoic Laurasia). Moreover, the burst in species diversity in Cyprinidae afforded by the nearly worldwide colonization is possibly in response to the plasticity of pharyngeal dentition. The present study demonstrates that the Cypriniformes was about 193 Mya during the early Jurassic, coinciding with the onset of the Pangaea breakup. The plasticity of pharyngeal dentition of cyprinids might contribute to the burst and radiation of this lineage. The phylogenetic and biogeographic analyses in this study help to improve our understanding of the evolutionary history of this diverse and important freshwater fish group.

Diversity of Rhabdochona mexicana (Nematoda: Rhabdochonidae), a parasite of Astyanax spp. (Characidae) in Mexico and Guatemala, using mitochondrial and nuclear genes, with the description of a new species.

Among fish parasitic nematodes Rhabdochona is one of the most speciose genera, with c. 100 species. Twelve congeneric species occur in Mexican freshwater fishes, in a region located between the Nearctic and Neotropical biogeographical regions. Host association and biogeographical history have determined the high species richness of Rhabdochona in Mexico. One of these species, Rhabdochona mexicana, is highly specific to the characid genus Astyanax. Characids are a group of freshwater fish with Neotropical affinity. In this paper, we explore the genetic diversity of R. mexicana through samples obtained from populations of Astyanax spp. across river basins of Mexico and Guatemala. Sequences of one mitochondrial and two ribosomal genes were obtained from 38 individuals and analysed using Maximum Likelihood and Bayesian Inference analysis. Phylogenetic analyses using cox1, and a concatenated alignment of 18S + 28S + cox1 recovered two genetic lineages. One of them corresponded with R. mexicana sensu stricto; this lineage included three reciprocally monophyletic subgroups; the other lineage was highly divergent and represented a putative candidate species. A detailed morphological study was conducted to corroborate the molecular findings. We describe a new species herein and discuss the implications of using molecular tools to increase our knowledge about the diversity of a speciose genus such as Rhabdochona.

Cryptic diversity within the Schistura robertsi species complex (Nemacheilidae).

Event Abstract Back to Event Cryptic diversity within the Schistura robertsi species complex (Nemacheilidae). Tomáš Dvořák1*, Jörg Bohlen1 and Vendula Šlechtová1 1 Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics (ASCR), Czechia The Schistura robertsi species complex is a group of freshwater fish inhabiting streams and rivers in southeast Myanmar and western and southern Thailand. The complex is believed to include five described and one undescribed species, but monophyly, outline and systematics of the complex have never been studies explicitly. The present study aims to resolve the number of species within the Schistura robertsi group as well as their distribution areas and their phylogenetic relations. We analysed mitochondrial and nuclear sequence data of 86 specimens from 47 localities and 18 morphologic characters of about 200 specimens. The phylogenetic analyses revealed the S. robertsi complex to be monophyletic and to be composed of ten major lineages. Six of them correspond to the known described or undescribed species, but another four reveal the existence of a cryptic diversity within the group. All genetic lineages are statistically highly supported, have distinct distribution areas and all are morphologically diagnosable, suggesting that they represent distinct species. Several cases of co-occurrence without sign of hybridisation exist. Acknowledgements The study got financial support from grants 206/08/0637 and 19-18453S of the Grant Agency of the Czech Republic. Keywords: molecular phylogeny, systematics, Biodiversity, freswater fish, South East Asia, Loach, morphology Conference: XVI European Congress of Ichthyology, Lausanne, Switzerland, 2 Sep - 6 Sep, 2019. Presentation Type: Poster Topic: TAXONOMY, PHYLOGENY AND ZOOGEOGRAPHY Citation: Dvořák T, Bohlen J and Šlechtová V (2019). Cryptic diversity within the Schistura robertsi species complex (Nemacheilidae).. Front. Mar. Sci. Conference Abstract: XVI European Congress of Ichthyology. doi: 10.3389/conf.fmars.2019.07.00126 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 May 2019; Published Online: 14 Aug 2019. * Correspondence: Mx. Tomáš Dvořák, Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics (ASCR), Liběchov, Czechia, dvorak@iapg.cas.cz Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Tomáš Dvořák Jörg Bohlen Vendula Šlechtová Google Tomáš Dvořák Jörg Bohlen Vendula Šlechtová Google Scholar Tomáš Dvořák Jörg Bohlen Vendula Šlechtová PubMed Tomáš Dvořák Jörg Bohlen Vendula Šlechtová Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Historical biogeography reveals new independent evolutionary lineages in the Pantosteus plebeius-nebuliferus species-group (Actinopterygii: Catostomidae)

BackgroundThe Pantosteus plebeius-nebuliferus species-group is a group of freshwater fishes distributed in endo- and exorheic drainage basins in the Mexican Sierra Madre Occidental mountain range system and central North Mexico. The geological history of this region is considered an important factor in explaining the evolutionary history of low vagility animals like freshwaters fishes. The aim of this study was to examine the phylogenetic relationships and describe the evolutionary history of the species-group. We hypothesized that the genetic structure and distribution of the main clades of Pantosteus plebeius-nebuliferus are associated with the geological history of Northern Mexico. To this end, we obtained DNA sequences of mitochondrial and nuclear genes and performed phylogenetic and phylogeographic analyses. Divergence time estimation and ancestral area reconstruction were also carried out to propose a biogeographical hypothesis, and species boundaries within the species-group were also tested.ResultsWe identified four clades within the Pantosteus plebeius-nebuliferus species-group in both markers. Divergence ranged from 5.9% to 9.2% for cytb and 0.1% to 0.9% for GHI. We observed significant genetic structure and no shared haplotypes between clades. We estimated that the clades diverged during the last 5.1 Myr, with a biogeographic scenario suggesting eight vicariant and four dispersal events through the historic range of the species-group. We found that the best species-delimitation model is when four species are assumed, which correspond to the main clades. We identified nine evolutionary significance units (ESUs), pertinent to the conservation of the group, each representing populations present in distinct drainage basins.ConclusionsThe evolutionary history of the Pantosteus plebeius-nebuliferus species-group is characterized by vicariant post-dispersal processes, linked to geological changes in the Sierra Madre Occidental and central Northern Mexico since the Pliocene. This is congruent with biogeographic patterns described for other co-distributed fish species. We propose a new phylogenetic hypothesis for the species-group, clarifying the taxonomy of this evolutionarily complex group. Our results suggest that the species-group consists of at least four clades with independent evolutionary histories, two of which may represent new undescribed species. Our identification of ESUs provides a basis upon which conservation measures can be developed for the species-group.

Evolutionary hotspot of Cenozoic fish: Paleogene ichthyofauna from the onshore basins around Beibu Gulf

Paleogene sediments are well developed in the onshore basins, including Ningming, Nanning, and Baise Basins of Guangxi, Sanshui and Maoming Basins of Guangdong, and Changchang Basin of Hainan, around the Beibu Gulf (Gulf of Tonkin). A large number of fish fossils have been recovered from these sediments. As our fieldwork and research activities progressed in recent years, the picture of the Paleogene ichthyofauna is gradually unveiled. Here we review the systematic paleontology of the fossil fishes and their implications on paleoecology and paleobiogeography. Known Paleogene fossil fishes from this region include cypriniforms, osteoglossiforms, siluriforms, and perciforms from Sanshui Basin; cypriniforms, siluriforms and sharks from Maoming Basin; cypriniforms from Changchang Basin; cypriniforms, siluriforms, and clupeomorphs from Nanning Basin; cypriniforms, †ellimmichthyiforms, siluriforms, and gobiiforms from Ningming Basin; and cypriniforms from Baise Basin. Among all these fossil fishes, cypriniforms, a group of primary freshwater fishes, were the dominant fishes in terms of specimen numbers and taxonomic diversity, which spanned from the Paleocene to the Oligocene and occurred in every basin of this region. Described cypriniforms from this region include (1) Cyprinidae: † Eoprocypris maomingensis from late Eocene Youganwo Formation of Maoming Basin; † Huashancyprinus robustispina and † Ecoparpia ningmingensis from Oligocene Ningming Formation of Ningming Basin, and † Nanningocyprinus wui from Oligocene Yongning Formation of Naning Basin; (2) Jianghanichthyidae (the only fossil family of the order Cypriniformes and only occurred in South China): † Jianghanichthys sanshuiensis from Paleocene Buxin Formation of Sanshui Basin; and (3) Cobitidae: † Cobitis nanningensis from Oligocene Yongning Formation of Nanning Basin. These fishes are among the oldest cypriniform fossils, which provide critical information on the origin and evolution of the largest extant freshwater fish order Cypriniformes. Moreover, Oligocene †ellimmichthyiforms (Clupeomorpha) and gobiiforms (Percomorpha) are important discoveries from this region. The former represents the first discovery of †ellimmichthyiform from the Oligocene worldwide which is younger than its known fossil records. The latter is the first occurrence of fossil gobiiforms in China. Furthermore, the most abundant Paleogene fishes of this region are cypriniforms, which are strict freshwater fish. Meanwhile, shark materials are also discovered along with possibly marine †ellimmichthyiform and siluriforms. The combination of above fishes indicates that the freshwater bodies of this region were invaded occasionally by marine water during the Paleogene. To conclude, the Paleogene ichthyofauna from onshore basins of Beibu Gulf consists of oldest fossils of major clades of Cenozoic fishes and a relict of typical Mesozoic fish taxa, which suggest that this region is an evolutionary hotspot of Cenozoic freshwater fishes, especially of cypriniforms. The vertebrate paleontology, systematics, taxonomy, and paleoecology of the fish assemblages from this region are pending further study. To understand the origin and divergence of the major clades of the Paleogene fish, as well as hypothesize on the development of the recent fish fauna of East and South Asia, we suggest conducting more comprehensive fieldwork to collect scientifically valuable specimens in the onshore basins around Beibu Gulf, and performing in-depth laboratory research using traditional paleontological methods, 2-D and 3D computational tools, and molecular data of related extant fishes.

Disentangling the drivers of diversification in an imperiled group of freshwater fishes (Cyprinodontiformes: Goodeidae)

BackgroundOne of the most perplexing questions in evolutionary biology is why some lineages diversify into many species, and others do not. In many cases, ecological opportunity has played an important role, leading to diversification along trophic or habitat-based axes. The Goodeidae (Teleostomi: Cyprinodontiformes) are a family of freshwater fishes with two subfamilies: Goodeinae (42 species, viviparous, heterogeneous habitats, Mesa Central of Mexico) and Empetrichthyinae (4 species, oviparous, homogeneous habitats, Great Basin of the United States). These discrepant sets of characteristics and their sister-group relationship make the goodeids amenable to a comparative study of diversification. We gathered lateral body images from more than 1600 specimens of all extant species in the family. Geometric morphometric, and phylogenetic comparative analyses were used to address whether higher species diversity correlates with higher rates of morphological shape evolution and whether there are differences in functional/habitat modules between the two subfamilies.ResultsThis study recovered a higher rate of overall body shape evolution in the Goodeinae that is nearly double in magnitude compared to the Empetrichthyinae. A modularity test indicated that the Goodeinae displayed elevated rates of morphological evolution in comparison to the Empetrichthyinae when only trunk (locomotor) regions were compared between subfamilies. No significant differences in evolutionary shape rates were recovered when the trophic (head) regions were compared between subfamilies.DiscussionThese results support the hypothesis that Mexican goodeids radiated via an ecological opportunity scenario into a wide-array of novel habitats in the island-like Mesa Central as evidenced by their high rate of shape evolution, relative to the Empetrichthyinae. This study quantitatively unraveled the drivers of evolution and eliminated trophic specialization as a driving force within the Goodeidae.ConclusionsA combination of phylogenetic and morphometric data, and phylogenetic comparative analyses were used to examine body shape rate evolution within the Goodeidae. Results support the hypothesis that species in the subfamily Goodeinae on the central Mexican plateau had a higher rate of body shape evolution relative to its sister subfamily Empetrichthyinae in the Great Basin suggesting that the Goodeinae diversified via an ecological opportunity scenario along habitat, rather than trophic axes.

Preference for conspecifics evolves earlier in males than females in a sexually dimorphic radiation of fishes.

Speciation by sexual selection is generally modeled as the coevolution of female preferences and elaborate male ornaments leading to behavioral (sexual) reproductive isolation. One prediction of these models is that female preference for conspecific males should evolve earlier than male preference for conspecific females in sexually dimorphic species with male ornaments. We tested that prediction in darters, a diverse group of freshwater fishes with sexually dimorphic ornamentation. Focusing on the earliest stages of divergence, we tested preference for conspecific mates in males and females of seven closely related species pairs. Contrary to expectation, male preference for conspecific females was significantly greater than female preference for conspecific males. Males in four of the 14 species significantly preferred conspecific females; whereas, females in no species significantly preferred conspecific males. Relationships between the strength of preference for conspecifics and genetic distance revealed no difference in slope between males and females, but a significant difference in intercept, also suggesting that male preference evolves earlier than females'. Our results are consistent with other recent studies in darters and suggest that the coevolution of female preferences and male ornaments may not best explain the earliest stages of behavioral isolation in this lineage.

Resolving Cypriniformes relationships using an anchored enrichment approach.

BackgroundCypriniformes (minnows, carps, loaches, and suckers) is the largest group of freshwater fishes in the world (~4300 described species). Despite much attention, previous attempts to elucidate relationships using molecular and morphological characters have been incongruent. In this study we present the first phylogenomic analysis using anchored hybrid enrichment for 172 taxa to represent the order (plus three out-group taxa), which is the largest dataset for the order to date (219 loci, 315,288 bp, average locus length of 1011 bp).ResultsConcatenation analysis establishes a robust tree with 97 % of nodes at 100 % bootstrap support. Species tree analysis was highly congruent with the concatenation analysis with only two major differences: monophyly of Cobitoidei and placement of Danionidae.ConclusionsMost major clades obtained in prior molecular studies were validated as monophyletic, and we provide robust resolution for the relationships among these clades for the first time. These relationships can be used as a framework for addressing a variety of evolutionary questions (e.g. phylogeography, polyploidization, diversification, trait evolution, comparative genomics) for which Cypriniformes is ideally suited.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-016-0819-5) contains supplementary material, which is available to authorized users.

Proteocephalid tapeworms (Cestoda: Onchoproteocephalidea) of loaches (Cobitoidea): Evidence for monophyly and high endemism of parasites in the Far East

The parasite fauna of loaches (Cypriniformes: Cobitoidea), a group of small bottom-dwelling freshwater fishes with a mostly Eurasian distribution, remains a largely unknown quantity. Here we revise the taxonomy of tapeworms of the genus Proteocephalus Weinland, 1858 (Cestoda: Proteocephalidae) that had been found in loaches from the Palaearctic Region (Central Europe, Japan and Russia [Primorsky Region]). Molecular phylogenetic analysis based on two nuclear (ssr- and lsrDNA) and two mitochondrial genes (cox1 and rrnL) revealed a monophyletic group consisting of four valid species nesting within the Proteocephalus-aggregate: (i) Proteocephalus sagittus (Grimm, 1872) from Barbatula barbatula (Europe, Russia and Tajikistan), (ii) Proteocephalus demshini n. sp. from Barbatula toni (Russian Far East — Primorsky Region), (iii) Proteocephalus midoriensis Shimazu, 1990 from Lefua echigonia (Japan) and L. costata (Russia) (new host and geographical record), and (iv) Proteocephalus misgurni n. sp. from Misgurnus anguillicaudatus (Russia; Primorsky Region). Proteocephalus sagittus and P. demshini, and P. midoriensis and P. misgurni were recovered as sister taxa, respectively. Proteocephalus sagittus and P. demshini are characterized by having proglottids that are wider than long, an elongate to pyriform cirrus-sac and the vitelline follicles that form wide lateral bands. Proteocephalus midoriensis and P. misgurni are characterized by having proglottids that are more elongate and an ovoid to almost spherical cirrus-sac and the vitelline follicles forming narrow lateral bands. Proteocephalus demshini differs from P. sagittus in the posterolateral extent of the vitelline follicles, whereas P. misgurni can be distinguished from P. midoriensis mainly by the relative size of the ovary, posterior extent of the vitelline follicles and width of the scolex. Unlike most species of the Proteocephalus-aggregate that possess an apical sucker, all species from loaches are devoid of any apical organ. The existence of two new species in loaches from the Primorsky Region of Russia indicates high endemism of fish parasites in this region. A key to the identification of recognized species from loaches is provided.

Phylogenetic analyses of the subgenus Mollienesia (Poecilia, Poeciliidae, Teleostei) reveal taxonomic inconsistencies, cryptic biodiversity, and spatio-temporal aspects of diversification in Middle America

The subgenus Mollienesia is a diverse group of freshwater fishes, including species that have served as important models across multiple biological disciplines. Nonetheless, the taxonomic history of this group has been conflictive and convoluted, in part because the evolutionary relationships have not been rigorously resolved. We conducted a comprehensive molecular phylogenetic analysis of the subgenus Mollienesia to identify taxonomic discrepancies and potentially identify undescribed species, estimate ancestral areas of origin and estimate dates of divergence, as well as explore biogeographical patterns. Our findings confirm the presence of three main clades composed of the P. latipinna, P. sphenops, and P. mexicana species complexes. Unlike previously hypothesized morphology-based analyses, species found on the Caribbean Islands are not part of Mollienesia, but are more closely related to species of the subgenus Limia. Our study also revealed several taxonomic inconsistencies and distinct lineages in the P. mexicana species complex that may represent undescribed species. The diversity in the subgenus Mollienesia is a result of dynamic geologic activity leading to vicariant events, dispersal across geologic blocks, and ecological speciation.

Colonizing the Caribbean: biogeography and evolution of livebearing fishes of the genus Limia (Poeciliidae)

AbstractAimWe investigate the origin and colonization of the West Indian endemic freshwater fish group Limia. We evaluate the leading hypotheses for the origins of West Indian life, including trans‐oceanic dispersal, late Cretaceous vicariance, and the GAARlandia land bridge at the Eocene/Oligocene boundary.LocationGreater Antilles, with extensive sampling in the Dominican Republic.MethodsWe obtained DNA from wild sampling and the aquarium trade. We sequenced three mitochondrial (12S, ND2 and Cytb) and two nuclear genes (Rh, MYH6) for a combined molecular phylogenetic analysis to evaluate species relationships and the timing of divergence events between islands and the mainland. We used Bayesian and likelihood approaches to build phylogenies, a BEAST analysis to establish the timing of colonization, and R package BioGeoBEARS to perform a historical biogeographical reconstruction.ResultsRelaxed molecular clock results show that the ancestor to the West Indian clade, which includes the Limia and Hispaniolan Poecilia, diverged from a South American ancestor at the Eocene/Oligocene boundary. The basal Jamaican species, L. melanogaster, split from the rest of Limia at the Oligocene/Miocene boundary. Cuban and Cayman taxa are sister to a diverse species group from Hispaniola. Historical biogeographical reconstruction supported the GAARlandia DEC+j model as the best fitting model for colonization.Main conclusionsOur results support a colonization model for Limia that is concordant with the timing of GAARlandia and climate change during the Eocene/Oligocene boundary. Limia colonization was most likely a result of facilitated dispersal during a period of lower sea levels and shorter passage along the Aves Ridge. These results are also consistent with other recent molecular clock studies of dispersal limited cichlids, toads and frogs, indicating a growing body of support for the significance of Eocene/Oligocene climate change for the historical biogeography of West Indian life.

Phylogenetic Correlation Between Male Nuptial Color and Behavioral Responses to Color Across a Diverse and Colorful Genus of Freshwater Fish (Etheostoma spp., Teleostei: Percidae)

AbstractSexual selection theory predicts that preferences in both sexes select for the elaboration of male nuptial coloration, with empirical evidence supporting these predictions. Empirical studies are often limited in their taxonomic inclusiveness, however, and typically do not examine how male and female preferences contribute to macroevolutionary patterns of male color variation across multiple lineages in a clade. This study examined color preferences in a group of dichromatic freshwater fishes known as darters (genus Etheostoma) that vary in the presence of male coloration. The strengths of attraction to black, blue, gray, and red models were tested in females of 18 species, in addition to males of five species. We found a positive association between the presence of red or orange on the body and the amount of time associating with red models, suggesting color variation is at least in part due to variation in female preferences between species. Males also spent more time associating with colors that most closely resembled conspecifics, suggesting that preferential responses to color in males also can contribute to the diversity of nuptial coloration in darters.

Using Different Methods to Access the Difficult Task of Delimiting Species in a Complex Neotropical Hyperdiverse Group

The genus Rineloricaria is a Neotropical freshwater fish group with a long and problematic taxonomic history, attributed to the large number of species and the pronounced similarity among them. In the present work, taxonomic information and different molecular approaches were used to identify species boundaries and characterize independent evolutionary units. We analyzed 228 samples assembled in 53 distinct morphospecies. A general mixed yule-coalescent (GMYC) analysis indicated the existence of 70 entities, while BOLD system analyses showed the existence of 56 distinct BINs. When we used a new proposed integrative taxonomy approach, mixing the results obtained by each analysis, we identified 73 OTUs. We suggest that Rineloricaria probably has some complexity in the known species and several species not formally described yet. Our data suggested that other hyperdiverse fish groups with wide distributions can be further split into many new evolutionary taxonomic units.

Assessing species boundaries using multilocus species delimitation in a morphologically conserved group of neotropical freshwater fishes, the Poecilia sphenops species complex (Poeciliidae).

Accurately delimiting species is fundamentally important for understanding species diversity and distributions and devising effective strategies to conserve biodiversity. However, species delimitation is problematic in many taxa, including ‘non-adaptive radiations’ containing morphologically cryptic lineages. Fortunately, coalescent-based species delimitation methods hold promise for objectively estimating species limits in such radiations, using multilocus genetic data. Using coalescent-based approaches, we delimit species and infer evolutionary relationships in a morphologically conserved group of Central American freshwater fishes, the Poecilia sphenops species complex. Phylogenetic analyses of multiple genetic markers (sequences of two mitochondrial DNA genes and five nuclear loci) from 10/15 species and genetic lineages recognized in the group support the P. sphenops species complex as monophyletic with respect to outgroups, with eight mitochondrial ‘major-lineages’ diverged by ≥2% pairwise genetic distances. From general mixed Yule-coalescent models, we discovered (conservatively) 10 species within our concatenated mitochondrial DNA dataset, 9 of which were strongly supported by subsequent multilocus Bayesian species delimitation and species tree analyses. Results suggested species-level diversity is underestimated or overestimated by at least ~15% in different lineages in the complex. Nonparametric statistics and coalescent simulations indicate genealogical discordance among our gene tree results has mainly derived from interspecific hybridization in the nuclear genome. However, mitochondrial DNA show little evidence for introgression, and our species delimitation results appear robust to effects of this process. Overall, our findings support the utility of combining multiple lines of genetic evidence and broad phylogeographical sampling to discover and validate species using coalescent-based methods. Our study also highlights the importance of testing for hybridization versus incomplete lineage sorting, which aids inference of not only species limits but also evolutionary processes influencing genetic diversity.

Comparative historical biogeography of three groups of Nearctic freshwater fishes across central Mexico

Biogeographic patterns of the three main Nearctic groups of continental fishes inhabiting river drainages in central Mexico (livebearing goodeids, southern Mexican notropins and species of Algansea, the last two representing independent lineages of cyprinids) were obtained and compared by following two approaches: an estimate of divergence times and using a well-defined biogeographic method. Three concordant biogeographic events were identified among the three groups, showing some evidence of a partially congruent evolutionary history. The analysed groups show at least three independent colonization events into central Mexico: two western routes, followed by the Goodeinae and members of Algansea, and an early Plateau route followed by southern notropins. The most recent common ancestor (MRCA) of each of the three freshwater fish groups diversified in central Mexico in the Late Miocene. The lack of a strong congruence in their biogeographic patterns, and the differences in species richness among the three clades might be evidence for distinct patterns of diversification.

Covariation of trophic and habitat‐related traits in chondrostoms (Cyprinidae): implications for repeated and diversifying evolutionary processes

AbstractThe tenet that ecological adaptation can lead to recurrent ecomorphological trends resulting from repetitive processes has long been a primary topic of investigation in evolutionary ecology. To explore this aspect further, this study provides an analysis of the morphological diversity in chondrostoms (Cyprinidae). This freshwater fish group shows a tendency towards bottom‐feeding specialization, which has led to evolutionary innovations in body and mouth shape traits, which are currently used for the classification of genera. Body, lower lip (LL) and corner ray shape were analysed for nine species in total. Allometric relationships among the three morphometric traits were considered to be responsible for LL shape variability and there was significant covariation between LL and body shape, which reflected habitat use. Smaller and opportunistic‐feeding species inhabiting stream or small‐sized rivers were characterized by a deeper body (increased feeding maneuverability), an arched LL and a terminal mouth position. Conversely, larger and diet‐specialized species were characterized by a fusiform body (increased swimming performance), a straight LL and an inframouth position on an elongated snout (optimized bottom feeding). The results suggest that interspecific mouth shape variability may have originated from two types of ‘deformation’ processes, both leading to a straight mouth shape and acting either jointly or independently. Also, given the plesiomorphic state of several of the species under study, the specialization towards a benthic lifestyle in chondrostoms from different phylogenetic lineages is thought to have occurred repeatedly to overcome a number of functional constraints, including foraging efficiency and swimming performance.

Comparative population genetic analysis of brackish- and freshwater populations of Eurasian perch (Perca fluviatilis L.): implication for fish forensics.

Event Abstract Back to Event Comparative population genetic analysis of brackish- and freshwater populations of Eurasian perch (Perca fluviatilis L.): implication for fish forensics. Lilian Pukk1*, Riho Gross1, Markus Vetemaa2 and Anti Vasemägi1, 3 1 Estonian University of Life Sciences, Department of Aquaculture, Estonia 2 University of Tartu, Estonian Marine Institute, Estonia 3 University of Turku, Department of Biology, Finland Understanding the genetic population structure of commercially important fish species is crucial for developing biologically sound management and conservation strategies. Genetic information can be also useful for fighting against illegal fishing and fish trade. Here, we studied commercially important brackish and freshwater populations of Eurasian perch (Perca fluviatilis L.) in Estonia, to describe the genetic divergence among populations and evaluate the power of 16 microsatellite markers to assign individual fish and group of fish to their population of origin. To do so, a total of 785 individuals caught from 13 different sites in the Baltic Sea and four locations in Lake Peipus were analyzed. We found significant differences in genetic diversity between brackish and freshwater populations with Baltic Sea samples showing slightly lower allelic richness and heterozygosity compared to Lake Peipus. We also observed moderate genetic differentiation among populations (overall FST=0.034). Individual self-assignment tests assigned large proportion of individuals correctly back to freshwater or coastal origin (Lake Peipus: 87.1%; Baltic Sea: 89.4%). Also, when evaluating the origin of group of individuals, it was possible to identify the origin of the brackish and freshwater fish groups with very high confidence (log 10 LR > 2) when sample size was larger than 15. Our results demonstrate the power of highly variable genetic markers separating two commercially most important Eurasian perch stocks in Estonia and the usefulness of assignment tests to successfully identify the genetic origin of fish. Keywords: Eurasian perch (Perca fluviatilis L.), population differentiation, Population assignment, Fish identification, forensics Conference: XV European Congress of Ichthyology, Porto, Portugal, 7 Sep - 11 Sep, 2015. Presentation Type: Oral Presentation Topic: Phylogeny, Systematics and Genetics Citation: Pukk L, Gross R, Vetemaa M and Vasemägi A (2015). Comparative population genetic analysis of brackish- and freshwater populations of Eurasian perch (Perca fluviatilis L.): implication for fish forensics.. Front. Mar. Sci. Conference Abstract: XV European Congress of Ichthyology. doi: 10.3389/conf.fmars.2015.03.00004 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 03 Nov 2015; Published Online: 04 Nov 2015. * Correspondence: Miss. Lilian Pukk, Estonian University of Life Sciences, Department of Aquaculture, Tartu, 51006, Estonia, lilian.pukk@emu.ee Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Lilian Pukk Riho Gross Markus Vetemaa Anti Vasemägi Google Lilian Pukk Riho Gross Markus Vetemaa Anti Vasemägi Google Scholar Lilian Pukk Riho Gross Markus Vetemaa Anti Vasemägi PubMed Lilian Pukk Riho Gross Markus Vetemaa Anti Vasemägi Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.