Integrative use of DNA barcode and morphology reveal high level of diversity in the ornamental fish on the lower Amazon basin.

The Amazon basin is the world's largest hydrographic basin, in terms of both its total area and its species diversity, with more than 2,700 species of fish. Despite this diversity, the data available on the fish fauna of the Amazon basin are still relatively scant and incomplete, in particular from the streams and floodplain lakes of the lower Amazon, which may contain a large proportion of the still undescribed species of the basin. Many of these species are expected to be of interest to the ornamental fish market.

External morphology and growth patterns of larvae and juveniles of Bryconops gracilis (Characiformes, Iguanodectidae) from Amazon basin.

During early development, fishes undergo significant changes that influence external morphology and the functioning of internal organs and systems. This often results in gradual variation of the morphological traits of individuals across developmental stages. The investigation of larval and juvenile fish development and growth patterns has pertinent implications for the systematic and ecological elucidation of species.

Knodus borari, a new species from the lower Rio Tapajós basin (Characiformes: Characidae).

A new species of Knodus from the Rio Cupari, a right-bank tributary of the lower Rio Tapajós, is described. Among its congeners, the new species shares exclusively with K. figueiredoi the presence of only uni-tricuspid teeth in the premaxilla, maxilla and dentary.

Biogeochemical water type influences community composition, species richness, and biomass in megadiverse Amazonian fish assemblages.

Amazonian waters are classified into three biogeochemical categories by dissolved nutrient content, sediment type, transparency, and acidity-all important predictors of autochthonous and allochthonous primary production (PP): (1) nutrient-poor, low-sediment, high-transparency, humic-stained, acidic blackwaters; (2) nutrient-poor, low-sediment, high-transparency, neutral clearwaters; (3) nutrient-rich, low-transparency, alluvial sediment-laden, neutral whitewaters. The classification, first proposed by Alfred Russel Wallace in 1853, is well supported but its effects on fish are poorly understood. To investigate how Amazonian fish community composition and species richness are influenced by water type, we conducted quantitative year-round sampling of floodplain lake and river-margin habitats at a locality where all three water types co-occur.

The true identity of Bryconops cyrtogaster (Norman), and description of a new species of Bryconops Kner (Characiformes: Iguanodectidae) from the Rio Jari, lower Amazon basin.

Bryconops cyrtogaster, a poorly known species endemic from the Oyapock River at the border between French Guyana and Brazil, is redescribed herein based on examination of available type material, as well as newly collected material. Additionally, a new rheophilic species from the rio Jari rapids, lower Amazon basin, Brazil, is described. The two species belong to the subgenus Creatochanes and are unique among the congeneres for possessing a posteriorly positioned humeral blotch at the level of the sixth and seventh lateral line scales.

A new species of Knodus (Characiformes: Characidae) from the Rio Cupari drainage, lower Rio Tapajós basin, Brazil.

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.

A new species of Bryconops Kner (Characiformes: Iguanodectidae) from the Rio Maicuru, lower Amazon basin, Brazil.

A new species of Bryconops is described from the rio Maicuru, a tributary of the left margin of the lower Amazon River, Pará, Brazil. Bryconops chernoffi new species, differs from all its congeners by the presence of an elongated dark patch of pigmentation immediately after the posterodorsal margin of the opercle, running vertically from the supracleithrum to the distal margin of the cleithrum (vs. absence of a similar blotch), and by a dark dorsal fin with a narrow hyaline band at middle portion of dorsal-fin rays (vs.

Stream ichthyofauna of the Tapajós National Forest, Pará, Brazil.

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 1(st) to 3(rd) order.

Bryconops munduruku (Characiformes: Characidae), a new species of fish from the lower Tapajós River basin, Brazil.

A new species of Bryconops is described from a right tributary of the lower Tapajós River, State of Pará, Brazil. Bryconops munduruku, sp. nov.