Progress in the acquisition of massive sets of molecular data and in the bioinformatic capabilities for their processing have revolutionised species identification, filling gaps in crucial areas such as taxonomy, phylogenetic inference, biogeography, and even biodiversity conservation. Advanced DNA sequencing and metabarcoding have uncovered previously hidden diversity, although their effectiveness is highly dependent on the accuracy of reference DNA databases at local and regional scales. The compilation of information on freshwater fishes from the Magdalena River basin is an important milestone in improving our knowledge of the genetic and taxonomic diversity of a highly endemic region in the Neotropical context.
View Article and Find Full Text PDFUnlike most rivers globally, nearly all lowland Amazonian rivers have unregulated flow, supporting seasonally flooded floodplain forests. Floodplain forests harbor a unique tree species assemblage adapted to flooding and specialized fauna, including fruit-eating fish that migrate seasonally into floodplains, favoring expansive floodplain areas. Frugivorous fish are forest-dependent fauna critical to forest regeneration via seed dispersal and support commercial and artisanal fisheries.
View Article and Find Full Text PDFAnimals living in caves are of broad relevance to evolutionary biologists interested in understanding the mechanisms underpinning convergent evolution. In the Eastern Andes of Colombia, populations from at least two distinct clades of Trichomycterus catfishes (Siluriformes) independently colonized cave environments and converged in phenotype by losing their eyes and pigmentation. We are pursuing several research questions using genomics to understand the evolutionary forces and molecular mechanisms responsible for repeated morphological changes in this system.
View Article and Find Full Text PDFWe recorded Pimelodella bockmanni and P. serrata for the first time for Colombia, based on specimens collected in tributaries from the main channel of the Amazonas River, in the so-called Trapecio Amazónico, in the southernmost region of this country. We also present morphometric, meristic, and osteological data of the examined material, and provide a complementary morphological description of the poorly known P.
View Article and Find Full Text PDFAn iterative analysis of Imparfinis, combining phylogenetic analysis based on cytochrome oxidase gene and multivariate morphometrics, revealed a new cryptic species from the Andean tributaries of the Orinoco River basin, which is described here. The new species is sister to a clade constituted by Imparfinis hasemani and Imparfinis pijpersi, both from the river basins of the Guiana Shield, being also the most geographically proximate species. Nonetheless, the new species is most similar in general appearance to Imparfinis guttatus from the Madeira and Paraguay River drainages, being almost undistinguishable by conventional characters of external morphology, differing only by morphometric attributes overall.
View Article and Find Full Text PDFThe Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data.
View Article and Find Full Text PDFA new species of Pimelodella is described from western Andean tributaries of the Orinoco River basin. The new species differs from all congeners by a unique set of characters that includes long maxillary barbel, surpassing the dorsal lobe of the caudal fin; relatively short adipose fin (32.8-36.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFThe family Trichomycteridae is one of the most diverse groups of freshwater catfishes in South and Central America with eight subfamilies, 41 genera and more than 300 valid species. Its members are widely distributed throughout South America, reaching Costa Rica in Central America and are recognized by extraordinary anatomical specializations and trophic diversity. In order to assess the phylogenetic relationships of Trichomycteridae, we collected sequence data from ultraconserved elements (UCEs) of the genome from 141 specimens of Trichomycteridae and 12 outgroup species.
View Article and Find Full Text PDFTrichomycterus spectrum is described as a new species from the Alejo cave, drained by the Ranchería River basin, in La Guajira department, north-eastern Colombia, and is the first troglomorphic species described from this region. The new species shows an advanced degree of troglomorphisms expressed as eyes absent, long barbels and body depigmented. Trichomycterus spectrum is diagnosed by the putatively autapomorphic presence of a posterior process at the anterolateral corner of the epioccipital, and is also recognized by the derived presence of a circular foramen on the neural spine of the complex vertebra and the following posterior vertebra, and by the apomorphic presence of a well-developed coracoid bridge, distally expanded, and contacting or almost reaching the lateral margin of the cleithrum.
View Article and Find Full Text PDFA new species of Hemigrammus is described from the Amazon Basin near Leticia, Departamento Amazonas, Colombia. In common with some congeners and some Hyphessobrycon spp., the new species colour pattern lacks a humeral blotch but has a caudal-peduncle blotch.
View Article and Find Full Text PDFTrichomycterus striatus is herein redescribed, based on examination of the types and recently collected specimens, and its geographic distribution is updated. This species can be diagnosed from all other northeastern South American congeners by its variable coloration pattern consisting of a yellowish to light brown background with a black lateral band and/or small dark brown spots on sides or uniformly light brown and by the following combination of characters: teeth conical arranged in three to four irregular rows in both jaws; anterior section of infraorbital canal (sensory pores i1 and i3) present; sensory pores s6 paired, 11-23 opercular odontodes; 27-44 interopercular odontodes; seven to eight pectoral-fin branched rays; 36-37 free vertebrae; 12-14 ribs; cleithrum pierced by several foramina; and caudal fin truncate to rounded. Trichomycterus striatus occurs from southern Costa Rica [from the Pirrís (herein reported for the first time), Térraba and Coto River basins] to eastern Panama (in most of the main river basins in both the Pacific and Atlantic versants), being the sole representative of the family in lower Central American waters.
View Article and Find Full Text PDFThe Cusiana River sub-basin has been identified as a priority conservation area in the Orinoco region in Colombia due to its high species diversity. This study presents an updated checklist and identification key for fishes of the Cusiana River sub-basin. The checklist was assembled through direct examination of specimens deposited in the main Colombian ichthyological collections.
View Article and Find Full Text PDFThe present work is part of a process to create a Catalogue of the Freshwater Fishes of Colombia and consisted in the depuration and updating of the taxonomic and geographic components of the checklist of the freshwater fishes of Colombia. An exhaustive revision of the 1435 species recorded in 2008 was necessary to: 1. Add new species described since 2009 and species originally described from Colombia but inadvertently omitted in 2008; 2.
View Article and Find Full Text PDFTrichomycteridae is the second most diverse family of the order Siluriformes, its members are widely distributed through the freshwaters of Central and South America, exhibiting an exceptional ecological and phenotypic disparity. The most diverse subfamily, Trichomycterinae, represented mainly by the genus Trichomycterus, historically has been recognized as non-monophyletic and various characters used to unite or divide its constituents are repeatedly called into question. No comprehensive molecular phylogenetic hypothesis regarding relationships of trichomycterids has been produced, and the present study is the first extensive phylogeny for the family Trichomycteridae, based on a multilocus dataset of three mitochondrial loci and two nuclear markers (3284bp total).
View Article and Find Full Text PDFZootaxa
September 2016
The catalog of type specimens of freshwater fishes deposited in the Colección de Peces Dulceacuícolas del Instituto de Investigación de Recursos Biológicos Alexander von Humboldt (IAvH-P) is presented. This list includes 483 specimens in 65 lots representing 11 holotypes and 472 paratypes of 48 nominal species. Corrections, additions, and updating of information in the original descriptions are included in individual remarks for each catalog number entry and a gallery of pictures of holotypes or paratypes of each nominal species is also presented, which supplements some original descriptions lacking figures of their respective types.
View Article and Find Full Text PDFTrichomycterus tetuanensis, new species, is described from the río Tetuan, upper río Magdalena basin in Colombia. The new species is distinguished by its margin of caudal fin conspicuously emarginate, in combination with a high number of opercular odontodes (21-39), reflected externally in the large size of the opercular patch of odontodes, 3 irregular rows of conic teeth in the upper jaw, 42-52 interopercular odontodes, 8 branchiostegal rays, 37 post Weberian vertebrae, 7 branched pectoral-fin rays, hypural 3 separated from hypural plate 4+5, and background coloration light brown with darker dots uniformly sparse on dorsum and sides of trunk. Some apomorphic characters informative for the phylogenetic affinities of the new species within Trichomycterus are discussed.
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