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.Scientific Data | (2020) 7:96 | https://doi.collections from Peru 25,26 and by initiating sampling campaigns in detected gaps in Colombia, Peru and Brazil. All these spatial gaps in the database will also be prioritized in future updates through literature and web-based sources checking. Researchers holding fish distribution data from any of the current gaps or under-sampled areas (Fig. 2) and that wish to share these data are welcome to join the project. This information will be included with the complete source, after validation, in the next update of the database.

A new Trichomycterus is described from a highland tributary of the río Meta (Orinoco basin), along the east flank of Páramo de Cruz Verde, Eastern Cordillera of Colombia. The new species is distinguished from most of its congeners by having a reduced posterior cranial fontanel, restricted to the parieto-supraoccipital, cleithrum pierced by several foramina, and an unique combination of four irregular rows of conic teeth in premaxilla and dentary, 13-14 opercular odontodes, 41-43 interopercular odontodes, 6-7 branchiostegal rays, 40 or 41 free vertebrae, 14-18 ribs, first ray of pectoral fin slightly projected as a short filament, 7-8 branched pectoral-fin rays, dorsal-fin origin at same level of pelvic-fin insertion, anal-fin origin posterior to dorsal-fin base, caudal-fin margin slightly rounded, a single upper hypural plate (3+4+5), and coloration pattern consisting in ground color dark brown with a thin mid-lateral dark stripe. Phylogenetic relationships of the new species based on the shared presence of derived features related to posterior cranial fontanel and cleithrum are discussed. The new species is also compared to the only two described species from Andean tributaries of río Orinoco basin.É descrita uma espécie nova de Trichomycterus de um pequeno tributário dos Andes da bacia do río Meta (bacia do río Orinoco), no flanco oriental do Páramo de Cruz Verde na Cordilhera Oriental da Colômbia. A espécie nova distingue-se da maioria de seus congêneres por apresentar uma fontanela craniana posterior reduzida, restrita ao parieto-supraoccipital, cleitro perfurado por vários forames e uma combinação única de quatro fileiras irregulares de dentes cónicos no pré-maxilar e no dentário, 13-14 odontódeos operculares, 41-43 odontódeos interoperculares, 6-7 raios branquiostégios, 40 ou 41 vértebras livres, 14-18 costelas, o primeiro raio da nadadeira peitoral ligeiramente projetado em um curto filamento, 7-8 raios ramificados na nadadeira peitoral, origem da nadadeira dorsal no mesmo nível de inserção das nadadeiras pélvicas, origem da nadadeira anal posterior à base da nadadeira dorsal, margem da nadadeira caudal ligeiramente arredondada, uma única placa hipural superior (3+4+5) e padrão de coloração em um fundo de cor marrom escuro com uma fina listra escura média lateral. As relações filogenéticas da espécie nova com base na presença compartilhada de caracteres derivados relacionados com a fontanela craniana posterior e o cleitro são discutidas. A espécie nova também é comparada com as duas únicas espécies descritas de afluentes dos Andes da bacia do río Orinoco.

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Reexamination of the syntypes of the enigmatic Trichomycterus venulosus, described from Páramo de Cruz Verde, Eastern Cordillera of Colombia, allowed us to assess its actual taxonomic status. This nominal species is demonstrated to constitute a junior synonym of Eremophilus mutisii, and then not represents a case of extinction of a fish endemic to Colombia, as currently accepted.

The 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. A total of 2020 lots from 167 different localities from the Cusiana River sub-basin were examined and ranged from 153 to 2970 m in elevation. The highest number of records were from the piedmont region (1091, 54.0 %), followed by the Llanos (878, 43.5 %) and Andean (51, 2.5 %). 241 species distributed in 9 orders, 40 families, and 158 genera were found. The fish species richness observed (241), represents 77.7 % of the 314 estimated species (95 % CI=276.1–394.8). The use of databases to develop lists of fish species is not entirely reliable; therefore taxonomic verification of specimens in collections is essential. The results will facilitate comparisons with other sub-basins of the Orinoquia, which are not categorized as areas of importance for conservation in Colombia.