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.

The fish fauna of freshwater streams in the Tapajos National Forest was surveyed and a list of species is presented. The sampling was conducted from 2012 to 2013 during the dry season. Fish were collected with dip nets and seine nets in 22 streams of 1st to 3rd order. Sampling resulted in 3035 specimens belonging to 117 species, 27 families and six orders. The most abundant species were Bryconops aff. melanurus, Hemigrammus belottii, and Hemigrammus analis. Four undescribed species were recognized, one of which is known only from the area of this study. A significant dissimilarity was observed in fish species composition among drainage systems. This is the first survey of the stream ichthyofauna in the Tapajós National Forest, and it presents relevant information for future studies and decision-making in the management and conservation of fish fauna in this conservation unit.

A new species of Knodus is described from the rio Cupari drainage, a tributary from the right margin of the lower rio Tapajós, Pará State, Brazil. The new species differs from its congeners, except K. geryi, by having a dark basal blotch on each caudal fin lobe (vs. caudal fin lobes with sparse chromatophores, lacking basal blotches) and, with the exception of K. borki, K. heteresthes, and K. pasco, by having 10–12 scales around the caudal peduncle (vs. 13–15).

A new species of Bryconops is described from a right tributary of the lower Tapajós River, State of Pará, Brazil. Bryconops munduruku, sp. nov., differs from its congeners, except B. inpai and B. piracolina, by having a black adipose fin (vs. adipose fin hyaline in alcohol) and, except B. inpai, by possessing two humeral blotches (vs. lack of humeral blotch or only one humeral blotch). Bryconops munduruku differs from B. inpai by having a uniform color pattern on the posterior portion of the side of the body (vs. a dark stripe extending posteriorly from the half of the anal-fin base onto the base of the middle caudal-fin rays). It differs further from B. inpai and B. piracolina by the presence of a black adipose fin that is hyaline along its base (vs. entirely black adipose fin in B. inpai and B. piracolina). The new species is allocated in the subgenus Creatochanes by having a maxillary bone with one to three teeth on both sides, and its posterior extension reaching the junction of second and third infraorbital bones.

Tatia comprises twenty-five valid species, distributed in the main inland watersheds of South America, including the Orinoco, Essequibo, and coastal rivers of Suriname, Amazon, upper rio Paraná and São Francisco basins. A new species is described from tributaries of upper rio Manuel Alves on uplands of Serra Geral do Tocantins plateau, Tocantins State, Brazil. It is promptly distinguished from all congeners, except Tatia britskii, due to absence of an adipose fin. It differs from T. britskii by the longer caudal peduncle length (24.1–30.5% SL, mean 25.3 vs. 20.0–22.7, mean 20.9); caudal peduncle depth (10.9–16.8 SL, mean 14.1 vs. 9.4–10.5, mean 9.8), and anterior cranial border with mesethmoid width equals its length (vs. width approximately three times its length in T. britskii). Additionally, information regarding the poorly known species Tatia simplex originally described from rio das Mortes, is provided.

A new species of Ammoglanis is described from the rio Aruri Grande, rio Jamanxim drainage, a right bank tributary to the middle rio Tapajós, Pará State, Brazil. The new species is identified and defined through morphological characters such as color pattern, consisting of eight or nine transverse dark bars regularly spaced along the dorsum; skeletal morphology; numbers of premaxillary teeth, vertebrae, and dorsal- and pectoral-fin rays; presence of cranial fontanel and two small, finger-like papillae on chin anterior to the gular apex. The new species probably is an additional example of endemism in the rio Tapajós basin.

A new species of Tatia is described from rio Tapajós, upstream of the rapids of São Luiz do Tapajós, Pará State, Brazil. The new species is identified and diagnosed from its congeners through morphological characteristics such as the absence of an adipose fin, which is shared with T. akroa and T. britskii; the composition of the cranial roof elements; the color pattern consisting of dorsolateral dark dots formed by both dermal and epidermal pigments; as well as several morphometric measures. The new species is a Centromochlinae fish that feeds on insects on the surface of the water at night and it is probably endemic to rio Tapajós basin.

A new species of Hypostomus with spoon-shaped teeth is described from the Rio Cupari basin, a right margin affluent of the lower Rio Tapajós, Pará State, Brazil. The new species inhabits rocky bottom areas in the main channel of Rio Cupari and its tributaries. The new species can be distinguished from all its congeners, except from the Hypostomus cochliodon group, by having six to eight spoon-shaped teeth, dentaries angled at less than 80 and the absence of a notch between the hyomandibular and the metapterygoid. The new species is distinguished from all species of the H. cochliodon group by its unique colour pattern, containing dark vermiculations on head and anterior portion of the trunk, and by the absence of medial buccal papillae.