The cardinal tetra is a freshwater fish of the family Characidae of order Characiformes. It is native to the upper Orinoco and Negro Rivers in South America. Growing to about 3 cm (1.2 in) total length, the cardinal tetra has the striking iridescent blue line characteristic of the genus Paracheirodon laterally bisecting the fish, with the body below this line being vivid red in color, hence the name "cardinal tetra". The cardinal tetra's appearance is similar to that of the closely related neon tetra, with which it is often confused; the neon's red coloration extends only about halfway to the nose, and the neon's blue stripe is a less vibrant blue.
The common hatchetfish or river hatchetfish is a tropical fish belonging to the freshwater hatchetfish family (Gasteropelecidae). Originating in South America in the Peruvian and middle Amazon, the Guianas and Venezuela, it grows to about 2.5 inches (6.4 cm). The fish gets its name from its relatively large protruding belly which resembles a hatchet. Hatchetfish will often jump out of the water when alarmed, propelled by their large, winglike pectoral fins. They also jump to catch small aerial insects.
The freshwater hatchetfish are a family, Gasteropelecidae, of ray-finned fish from South and Central America. The common hatchetfish is the most popular member among fish keeping hobbyists. The family includes three genera: Carnegiella, Gasteropelecus, and Thoracocharax.
The black-winged hatchetfish is a freshwater ray-finned fish native to South America.
Apistogramma agassizii, commonly known as Agassiz's dwarf cichlid, is a species of cichlid found in the Marañón and Ucayali River in Peru, some tributaries of the Amazon River, as well as downstream to the estuary in the Atlantic. It is named after the Swiss-American zoologist and geologist Louis Agassiz (1807–1873).
Abramites hypselonotus – known as the marbled headstander or the high-backed headstander – is a member of the family Anostomidae of the order Characiformes. Under normal fish classifying rules, the marbled headstander would be classified as a surface dweller. In reality marbled headstanders – like all headstanders – inhabit the middle and lower portions of the aquarium. In the wild, head standers are often found face down, tail up in narrow vertical rocky fissures.
Iguanodectes is a genus of freshwater fish found in tropical South America, with eight currently described species. They are all small tetras, none longer than 5 inches, and often have attractive silvery or striped scales, which makes them a target for the ornamental fish industry. Alongside the genus Piabucus, it is in the subfamily Iguanodectinae, which in turn is in the family Iguanodectidae. The genus Bryconops, which is also in Iguanodectidae, makes up a sister clade to Iguanodectinae.
Piabucus is a genus of freshwater tetras in the family Iguanodectidae. All three species are found in South America, largely the Amazon and its major tributaries. None of them are longer than half a foot long, with the largest reaching a maximum size of 12.9 cm (5.1 in), and they are slender, with relatively deep chests and long pectoral fins. Their scales are pale or silvery, with lateral lines that stand out.
Carnegiella is a genus of freshwater hatchetfishes found in the Amazon and Orinoco basins in South America. This genus contains some popular aquarium fishes.
Thoracocharax stellatus, the silver hatchetfish, spotfin hatchetfish, spotted hatchetfish or platinum hatchetfish, is a widespread hatchetfish found throughout South America including Venezuela, Colombia, Ecuador, Brazil, Peru, Bolivia, Paraguay, and Argentina in the Amazon, Orinoco, Paraguay and Tocantins-Araguaia basins. This species is one of the largest of the hatchetfishes. It is usually found in areas with abundant riparian vegetation.
Iguanodectinae is a subfamily of small freshwater fish in the family Iguanodectidae. They are most prominently found in the Amazon river basin and its major tributaries, but they are also known from the Tocantins, Orinoco, and Paraguay rivers. It has two genera, Piabucus and Iguanodectes. Some species in the subfamily are taken from the wild for aquariums, like the red- and green-line lizard tetras. There is minor, but ongoing, debate regarding its taxonomy.
The orangefin tetra is a small species of freshwater fish from South America that belongs to the family Iguanodectidae. Though common in its native range, it seems to prefer fast-flowing and shallow creeks. It is an active swimmer that feeds on plant material and various invertebrates, sometimes jumping out of the water to catch prey above the surface.
The tailspot tetra is a freshwater fish that lives in the coastal river regions of upper South America. Both its common and scientific names reference the distinct spot of color present on the tail fin, which is one of its defining characteristics. It is a small fish, reaching 4.8 in at its longest. Despite its small size, it is an active swimmer, with a preference for fast-flowing waters.
Bryconops colanegra is a small, slender-bodied species of freshwater fish from South America, about 3.5 in long. It has a black tail fin that bears hints of red, and its scales are dark along the back, transitioning to a silver belly. It is endemic to a single river system in Venezuela, the Rio Caroní.
Bryconops collettei is a small freshwater fish from the rivers of South America. It is mostly silvery, with notable green iridescence on its sides, and a diffuse ocellus (eyespot) on the upper lobe of the caudal fin. Before its distinction as a separate species, specimens of B. collettei were misidentified as specimens of Bryconops caudomaculatus due to several morphological similarities, including a caudal ocellus and generally similar fin coloration.
Bryconops cyrtogaster is a midsize species of freshwater fish found in the Oyapock river in French Guiana and Brazil. It is overall silver, with an indistinct dark patch at the base of the tail fin that spreads onto the fin rays slightly. Originally described in 1926 under a different baisonym, it was the subject of a redescription in June 2020.
Iguanodectes adujai is a species of freshwater fish that inhabits the rivers of South America. It largely prefers slow-moving blackwater habitats, though it has a slender body that suggests a further affinity for flowing water. It has a distinct lateral stripe in two horizontal sections, with bright-red at the top and yellow at the bottom.
Iguanodectes rachovii is a species of freshwater fish that inhabits the rivers of the Amazon basin. It largely consumes insects, though it will eat plants if given the opportunity, and has a peaceful disposition, able to live alongside various other species. It is often found in groups of 3 to 30 specimens, lingering at the edges of streams near the surface of the water.
Iguanodectes spilurus, the green-line lizard tetra, is a small characiform fish from the rivers of South America. It is not a well-studied species, but research is available, including data from hobbyists that keep it as an ornamental fish. It has a distinct lateral stripe of reflective-green scales, and lacks any red markings therein; red is common in congeners' lateral stripes.
Piabucus dentatus, also called the chin tetra or the coastal piabucus, is a small freshwater fish from the rivers of South America. It has a wide range that includes multiple coastal drainage systems, and was once mistakenly cited from Peru. Preferred habitats are generally high in silt content and are slow-moving, including floodplain streams and estuaries.
