#characiformes

[uncharismatic-fauna]

Uncharismatic Fact of the Day

The vampire fish might not actually drink blood, but it certainly looks the part! Also known as the payara, they are known for their extremely long lower teeth-- in fully grown adults, they can reach up to 15 cm (6 in). Because of their length, payara skulls have hollow sockets to sheath their lower teeth when their mouths are closed.

(Image: Researcher Zeb Hogan holding a payara (Hydrolycus scomberoides) by National Geographic)

[herpsandbirds]

Emperor Tetra (Nematobrycon palmeri), T - male, b - female, family Acestrorhamphidae, order Characiformes, found in 2 river basins in western Colombia

The bottom photo shows a more purplish form, which has been bred for the aquarium industry.

photographs: Aggiefish & Okyms Aquatic

[bestanimal]

Round 3 - Actinopterygii - Characiformes

(Sources - 1, 2, 3, 4)

Order: Characiformes

Common Name: “characins”

Families: 28 - Citharinidae (“lutefishes”), Distichodontidae, Crenuchidae, Alestidae (“African tetras”), Lepidarchidae (“Niger Tetra” and “Adonis Tetra”), Hepsetidae (“African pikes”), Tarumaniidae (“Muckfish”), Erythrinidae (“trahiras”), Parodontidae (“darter tetras”), Cynodontidae (“dogtooth characins”), Serrasalmidae (“pacu”, “piranha”, “silver dollar”, and kin), Hemiodontidae, Anostomidae (“toothed headstanders”), Chilodidae (“headstanders”), Curimatidae (“toothless characins”), Prochilodontidae (“flannel-mouthed characins”), Lebiasinidae, Ctenoluciidae (“pike-characins”), Chalceidae (“tucanfishes”), Triportheidae (“hatchet characins”), Gasteropelecidae (“freshwater hatchetfish”), Bryconidae, Iguanodectidae, Acestrorhynchidae (“freshwater barracudas” and “biting tetras”), Spintherobolidae (“piquiras”), Stevardiidae, Characidae, and Acestrorhamphidae (“American tetras”)

Anatomy: resemble Cypriniformes, but have a small, fleshy adipose fin between the dorsal fin and tail; most species have teeth; well-defined scales; have a Weberian apparatus, a series of bony parts connecting the swim bladder and inner ear

Diet: wide variety: many are carnivorous, eating prey ranging from fish to insects; some eat plants, nuts, and/or algae

Habitat/Range: Africa and Americas, are most diverse in the Neotropics; found in lakes and rivers

Evolved in: Late Cretaceous

Do you have a favorite in Characiformes?

One or more of my favorite animals is in Characiformes

I love at least one or more of these animals

I like at least one or more of these animals

I am neutral about all of these animals

I dislike all of these animals

Voting ended onJul 2, 2025

Propaganda under the cut:

The largest characin is the Goliath Tigerfish (Hydrocynus goliath) (image 3), which has an average adult length of 1.5 m (4.9 ft) and a weight of 50 kg (110 lb), and a maximum recorded length of about 2 m (6.6 ft) and weight of 70 kg (154 lb). The Goliath Tigerfish is known for its large, interlocking, dagger-like teeth, used for biting into prey fish. On average each of its teeth can grow up to 2.5 cm (1 in) long, comparable to the tooth size of a Great White Shark!

The Bolivian Pygmy Blue Characin (Xenurobrycon polyancistrus) is the smallest characin, with adults growing up to 1.4 cm (0.55 in) long.

Many of the most popular freshwater aquarium fish belong to this order, namely the small, colorful, peaceful “tetras”, which are often kept in tropical community tanks.

Relative to body mass, the Black Piranha (Serrasalmus rhombeus) produces one of the most forceful bites measured in vertebrates. It is also the largest species of piranha, with a maximum length of 41.5–61 centimetres (1.4-2 feet). These fish are opportunistic and omnivorous feeders which will eat plants, fallen fruits, and animals smaller than themselves such as insects and small fishes. They are also scavengers, and will feed on carcasses within the river.

The Red-bellied Piranha (Pygocentrus nattereri) (image 1) makes sounds to communicate with other members of its school, usually when exhibiting aggressive behavior such as biting, chasing, confrontation, and fighting. When handled by humans, they emit a drumming-like sound, consisting of a low-frequency harmonic sound. The sounds created by piranhas are generated through rapid contractions of the sonic muscles and is associated with the swimbladder. The swimbladder may play an important role in sound production as a resonator.

Piranhas (subfamily Serrasalminae) are some of the most misunderstood fish. While the schooling omnivores do sometimes bite bathers and swimmers, and will feed on drowned corpses, serious attacks are rare, and the fish generally avoid humans. Only two fatal attacks are known. They are eaten by humans far more often than the other way around! Their reputation as voracious predators is due to a “prank” once played on former US president Theodore Roosevelt, when he visited Brazil in 1913. Local fishermen had blocked off part of the river for days, starving the piranha in anticipation of Roosevelt’s visit. While the president watched, the fishermen pushed a cow into the water, which was quickly torn apart by the starving fish. Roosevelt went on to describe piranhas as vicious creatures which could skeletonize a cow in seconds in his 1914 book Through the Brazilian Wilderness.

Pacu, herbivorous members of the Serrasalmidae family, have large, molar-like teeth, used for crushing nuts that fall from trees. Their reputation for “biting testicles” comes from a joke that got out of hand! In 2013, a pacu was caught in the Øresund, a strait between Sweden and Denmark. A professor stated in a news release that the fish use their teeth to crunch on nuts, so “anyone choosing to bathe in the Oresund these days had best keep their swimsuits well tied!” The statement got a bit too much publicity, leading to a rumor that pacu will actually bite people’s balls off. Goes to show that media literacy has been dying for quite a while now, and not just on Tumblr.

[every-day-creechur]

Nile Robber Alestes dentex

Found in Central and West Africa. Alestes dentex is known to feed on seeds, zooplankton, and insects.

image by afropavo

[taxonomytournament]

Taxonomy Tournament: Fish

Characiformes. This order is made up of often carnivorous fish, such as the piranha, x-ray tetra and lutefish

Cypriniformes. This order is made up of carps and their relatives, such as minnows and loaches.

Which clade of animals is better?

Characiformes

Cypriniformes

Show results

Voting ended onJan 30, 2024

[have-you-seen-this-animal]

Rhoadsia sp. (altipinna and minor) ^_^

Have you seen a member of the genus Rhoadsia?

I have now

Yes, in photos/videos

Yes, irl

I'm not sure

Voting ended onOct 8, 2024

[wikipediapictures]

Hyphessobrycon caru

“Figure 1; Hyphessobrycon caru sp. nov., CICCAA 02286, holotype, 22.2 mm SL; Brazil: Maranhão state: Buritizinho River, Pindaré river drainage, Mearim river basin.” - via Wikimedia Commons

[snototter]

Goliath Tigerfish (Hydeocynus goliath) at Crocus City Oceanarium, Moscow by nmorozow Nik