Hypostomus formosae, a new catfish species from the Paraguay River Basin with redescription of H. boulengeri (Siluriformes: Loricariidae)

Hypostomus formosae n. sp. is described for the Paraguay river basin, Argentina. It can be distinguished from all other Hypostomus by having the combination of the following features: dorsum of head, body and all fins bright grey covered by numerous rounded dark dots and 11 ventral plates between end of anal-fin base and caudal fin (vs. more than 11). In addition, the new species is distinguished from the most similar sympatric species, H. boulengeri by slightly higher cleithral width, dorsal-fin base length, caudal-peduncle depth and by narrower caudal-peduncle length, eye diameter and mandibulary ramus length. Hypostomus formosae belongs to the Amazonian "H. plecostomus species group" and our molecular phylogenetic results show that it is the sister species to the Guianese H. plecostomus, highlighting past inter-basin ichtyofauna exchanges. We also provide detailed record of H. boulengeri for the first time in Argentina, collected in Paraguay river, at Formosa city.Instituto de Limnología "Dr. Raúl A. Ringuelet

Hypostomus formosae, a new catfish species from the Paraguay River Basin with redescription of H. boulengeri (Siluriformes: Loricariidae)

Hypostomus formosae n. sp. is described for the Paraguay river basin, Argentina. It can be distinguished from all other Hypostomus by having the combination of the following features: dorsum of head, body and all fins bright grey covered by numerous rounded dark dots and 11 ventral plates between end of anal-fin base and caudal fin (vs. more than 11). In addition, the new species is distinguished from the most similar sympatric species, H. boulengeri by slightly higher cleithral width, dorsal-fin base length, caudal-peduncle depth and by narrower caudal-peduncle length, eye diameter and mandibulary ramus length. Hypostomus formosae belongs to the Amazonian "H. plecostomus species group" and our molecular phylogenetic results show that it is the sister species to the Guianese H. plecostomus, highlighting past inter-basin ichtyofauna exchanges. We also provide detailed record of H. boulengeri for the first time in Argentina, collected in Paraguay river, at Formosa city.Instituto de Limnología "Dr. Raúl A. Ringuelet

A continental-wide molecular approach unraveling mtDNA diversity and geographic distribution of the Neotropical genus Hoplias

With an estimate of around 9,000 species, the Neotropical region hosts the greatest diversity of freshwater fishes of the world. Genetic surveys have the potential to unravel isolated and unique lineages and may result in the identification of undescribed species, accelerating the cataloguing of extant biodiversity. In this paper, molecular diversity within the valuable and widespread Neotropical genus Hoplias was assessed by means of DNA Barcoding. The geographic coverage spanned 40 degrees of latitude from French Guiana to Argentina. Our analyses revealed 22 mitochondrial lineages fully supported by means of Barcode Index Number, Automatic Barcode Gap Discovery and phylogenetic analyses. This mtDNA survey revealed the existence of 15 fully supported mitochondrial lineages within the once considered to be the continentally distributed H. malabaricus. Only four of them are currently described as valid species however, leaving 11 mitochondrial lineages currently “masked” within this species complex. Mean genetic divergence was 13.1%. Barcoding gap analysis discriminated 20 out of the 22 lineages tested. Phylogenetic analyses showed that all taxonomically recognized species form monophyletic groups. Hoplias malabaricus sensu stricto clustered within a large clade, excluding the representatives of the La Plata River Basin. In the H. lacerdae group, all species but H. curupira showed a cohesive match between taxonomic and molecular identification. Two different genetic lineages were recovered for H. aimara. Given the unexpected hidden mitochondrial diversity within H. malabaricus, the COI sequence composition of specimens from Suriname (the type locality), identified as H. malabaricus sensu stricto, is of major importance.Facultad de Ciencias Naturales y Muse

Unexpected species diversity in electric eels with a description of the strongest living bioelectricity generator

Is there only one electric eel species? For two and a half centuries since its description by Linnaeus, Electrophorus electricus has captivated humankind by its capacity to generate strong electric discharges. Despite the importance of Electrophorus in multiple fields of science, the possibility of additional species-level diversity in the genus, which could also reveal a hidden variety of substances and bioelectrogenic functions, has hitherto not been explored. Here, based on overwhelming patterns of genetic, morphological, and ecological data, we reject the hypothesis of a single species broadly distributed throughout Greater Amazonia. Our analyses readily identify three major lineages that diverged during the Miocene and Pliocene—two of which warrant recognition as new species. For one of the new species, we recorded a discharge of 860 V, well above 650 V previously cited for Electrophorus, making it the strongest living bioelectricity generator. © 2019, The Author(s)

A database of freshwater fish species of the Amazon Basin

The Amazon Basin is an unquestionable biodiversity hotspot, containing the highest freshwater biodiversity on earth and facing off a recent increase in anthropogenic threats. The current knowledge on the spatial distribution of the freshwater fish species is greatly deficient in this basin, preventing a comprehensive understanding of this hyper-diverse ecosystem as a whole. Filling this gap was the priority of a transnational collaborative project, i.e. the AmazonFish project - https://www.amazon-fish.com/. Relying on the outputs of this project, we provide the most complete fish species distribution records covering the whole Amazon drainage. The database, including 2,406 validated freshwater native fish species, 232,936 georeferenced records, results from an extensive survey of species distribution including 590 different sources (e.g. published articles, grey literature, online biodiversity databases and scientific collections from museums and universities worldwide) and field expeditions conducted during the project. This database, delivered at both georeferenced localities (21,500 localities) and sub-drainages grains (144 units), represents a highly valuable source of information for further studies on freshwater fish biodiversity, biogeography and conservation

Genetic landscape clustering of a large DNA barcoding dataset reveals shared patterns of genetic divergence among freshwater fishes of the Maroni Basin

The Maroni is one of the most speciose basins of the Guianas and hosts a megadiverse freshwater fish community. Although taxonomical references exist for both the Surinamese and Guyanese parts of the basin, these lists were mainly based on morphological identification and there are still taxonomical uncertainties concerning the status of several fish species. Here we present a barcode dataset of 1,284 COI sequences from 199 freshwater fish species (68.86% of the total number of strictly freshwater fishes from the basin) from 124 genera, 36 families, and 8 orders. DNA barcoding allowed for fast and efficient identification of all specimens studied as well as unveiling a consequent cryptic diversity, with the detection of 20 putative cryptic species and 5 species flagged for re-identification. In order to explore global genetic patterns across the basin, genetic divergence landscapes were computed for 128 species, showing a global trend of high genetic divergence between the Surinamese south-west (Tapanahony and Paloemeu), the Guianese south-east (Marouini, Litany, Tampok, Lawa…), and the river mouth in the north. This could be explained either by lower levels of connectivity between these three main parts or by the exchange of individuals with the surrounding basins. A new method of ordination of genetic landscapes successfully assigned species into cluster groups based on their respective pattern of genetic divergence across the Maroni Basin: genetically homogenous species across the basin were effectively discriminated from species showing high spatial genetic fragmentation and possible lower capacity for dispersal

Hypostomus formosae, a new catfish species from the Paraguay River Basin with redescription of H. boulengeri (Siluriformes: Loricariidae)

Hypostomus formosae n. sp. is described for the Paraguay river basin, Argentina. It can be distinguished from all other Hypostomus by having the combination of the following features: dorsum of head, body and all fins bright grey covered by numerous rounded dark dots and 11 ventral plates between end of anal-fin base and caudal fin (vs. more than 11). In addition, the new species is distinguished from the most similar sympatric species, H. boulengeri by slightly higher cleithral width, dorsal-fin base length, caudal-peduncle depth and by narrower caudal-peduncle length, eye diameter and mandibulary ramus length. Hypostomus formosae belongs to the Amazonian ?H. plecostomus species group? and our molecular phylogenetic results show that it is the sister species to the Guianese H. plecostomus, highlighting past inter-basin ichtyofauna exchanges. We also provide detailed record of H. boulengeri for the first time in Argentina, collected in Paraguay river, at Formosa city.Fil: Cardoso, Yamila Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Brancolini, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Paracampo, Ariel Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Lizarralde, Marta Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Covain, Raphael. Muséum d’Histoire naturelle de la Ville de Genève; SuizaFil: Montoya Burgos, Juan I.. Université de Genève; Suiz

Aquarium trade and fish farms as a source of non-native freshwater fish introductions in French Guiana

International audienceRivers of French Guiana are still little invaded by non-native fish, but several fish introductionswere recently recorded through the development of aquarium fish trade and fish farms. Here we reportrecords of 11 non-native fish species. Among them, four (Cichla monoculus, Heros efasciatus, Mesonautaguyanae and Poecilia reticulata) are established and one of them (Heros efasciatus) is rapidly increasing itsspatial range. Two species (Hyphessobrycon eques and Pterophyllum scalare) were not retrieved in recentrecords and are probably extinct from French Guiana. The establishment status of the five other species(Arapaima gigas, Colossoma macropomum, Cyprinus carpio, Oreochromis mossambicus andOsteoglossum bicirrhosum) is uncertain and only a few specimens were observed in the wild.Nevertheless, these species, intensively reared in nearby countries, belong to highly invasive species able tocause detrimental impacts on recipient ecosystems. Those first occurrences of invasive fish species in FrenchGuiana should therefore act as an early warning for both researchers and environmental managers

A continental-wide molecular approach unraveling mtDNA diversity and geographic distribution of the Neotropical genus <i>Hoplias</i>

<div><p>With an estimate of around 9,000 species, the Neotropical region hosts the greatest diversity of freshwater fishes of the world. Genetic surveys have the potential to unravel isolated and unique lineages and may result in the identification of undescribed species, accelerating the cataloguing of extant biodiversity. In this paper, molecular diversity within the valuable and widespread Neotropical genus <i>Hoplias</i> was assessed by means of DNA Barcoding. The geographic coverage spanned 40 degrees of latitude from French Guiana to Argentina. Our analyses revealed 22 mitochondrial lineages fully supported by means of Barcode Index Number, Automatic Barcode Gap Discovery and phylogenetic analyses. This mtDNA survey revealed the existence of 15 fully supported mitochondrial lineages within the once considered to be the continentally distributed <i>H</i>. <i>malabaricus</i>. Only four of them are currently described as valid species however, leaving 11 mitochondrial lineages currently “masked” within this species complex. Mean genetic divergence was 13.1%. Barcoding gap analysis discriminated 20 out of the 22 lineages tested. Phylogenetic analyses showed that all taxonomically recognized species form monophyletic groups. <i>Hoplias malabaricus sensu stricto</i> clustered within a large clade, excluding the representatives of the La Plata River Basin. In the <i>H</i>. <i>lacerdae</i> group, all species but <i>H</i>. <i>curupira</i> showed a cohesive match between taxonomic and molecular identification. Two different genetic lineages were recovered for <i>H</i>. <i>aimara</i>. Given the unexpected hidden mitochondrial diversity within <i>H</i>. <i>malabaricus</i>, the COI sequence composition of specimens from Suriname (the type locality), identified as <i>H</i>. <i>malabaricus sensu stricto</i>, is of major importance.</p></div