Ctenobrycon is a genus of deep-bodied, laterally compressed characins (family Characidae) found across a broad swath of northern and central South America, with atlas records spanning Venezuela, Colombia, the Guianas, Brazil, Bolivia, Peru, and Paraguay. The six species range from a modest 2 in up to over 6.5 in, larger at the top end than most fish sold under the generic label "tetra." Silvery and disc-shaped in profile, they are schooling fish of lowland rivers, floodplains, and quiet backwaters typical of many South American characins in this size class.
The genus's best-known member is C. spilurus, the silver tetra, a deep-bodied schooling characin that was among the earlier South American tetras to reach the aquarium trade, valued for its hardiness and undemanding water even though it has since been overshadowed by smaller, more colorful tetra genera. The rest of the genus - including C. hauxwellianus, C. kennedyi, and the Magdalena-basin C. magdalenae - sees little to no aquarium trade and is better known from regional ichthyological surveys. Conservation status is reassuring where assessed: four of the six species are Least Concern, with one Data Deficient and one Not Evaluated, and none is currently flagged under the CARES conservation program.