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Characins

Explore all characins in our database. Browse detailed care guides, compatibility information, and species data to find the perfect fish for your aquarium.

Showing 1 - 22 of 22 Fish Profiles

Beckford's Pencilfish

Nannostomus beckfordi

Characins
6.5 cm Peaceful

A peaceful, slender schooling fish native to the sluggish rivers and swamps of South America. They are famous for the males' harmless but spectacular lateral sparring displays. They require heavily planted aquariums with gentle flow and make excellent tank mates for other peaceful, soft-water species. A tight-fitting lid is essential as they are known to be proficient jumpers.

Black Neon Tetra

Hyphessobrycon herbertaxelrodi

Characins
4 cm Peaceful

A peaceful, active schooling fish native to the Paraguay basin. Known for its striking contrast of a dark black lateral stripe underneath a glowing iridescent white/green-gold stripe. Excellent for community aquariums, particularly in planted setups or blackwater biotope tanks with subdued lighting.

Black Pacu

Colossoma macropomum

Characins
90 cm Mostly Peaceful

The Black Pacu (Tambaqui) is a massive, incredibly fast-growing Amazonian fish. Closely related to Piranhas, they possess crushing, human-like teeth evolved for cracking nuts and seeds. Due to their enormous adult size (often exceeding 3 feet and 60 lbs) and extreme bioload, they are completely unsuitable for standard home aquariums and require colossal custom tanks or heated indoor ponds.

Black Skirt Tetra

Gymnocorymbus ternetzi

Characins
7 cm Mostly Peaceful

A very hardy, deep-bodied schooling tetra native to South America. They are incredibly popular for beginners but have a reputation as fin-nippers if kept in too small a group. A proper school disperses their internal bickering and largely prevents them from harassing other tank mates.

Bleeding Heart Tetra

Hyphessobrycon erythrostigma

Characins
7 cm Peaceful

A relatively large, deep-bodied tetra known for the distinctive bright red spot on its flank resembling a bleeding heart. They are active schoolers that require plenty of swimming space. While generally peaceful, they can become fin-nippers if kept in numbers fewer than 6 or in an undersized aquarium.

Blind Cave Tetra

Astyanax mexicanus

Characins
10 cm Mostly Peaceful

A fascinating, totally blind species originating from limestone caves in Mexico. They are born with eyes that degenerate as they grow. Navigating via their highly sensitive lateral line, they are extremely active and constantly scavenge for food. Best kept in a species tank or with fast-moving, short-finned fish, as their erratic swimming and feeding style can result in accidental fin-nipping of slow tank mates.

Bucktooth Tetra (Exodon)

Exodon paradoxus

Characins
12 cm Highly Aggressive

The Bucktooth Tetra is a highly active, predatory shoaling fish infamous for its scale-eating (lepidophagous) behavior. They are extremely aggressive and will strip the scales, fins, and even eyes off almost any tankmate. They must be kept in a species-only tank in large groups (12+) to disperse their intense conspecific aggression; otherwise, they will systematically kill each other.

Cardinal Tetra

Paracheirodon axelrodi

Characins
4 cm Peaceful

A stunning schooling fish native to the upper Orinoco and Rio Negro basins in South America. Famous for its brilliant iridescent blue line and a vivid red stripe that extends the full length of its body (distinguishing it from the Neon Tetra). They are strictly schooling fish that thrive in warm, acidic blackwater environments.

Congo Tetra

Phenacogrammus interruptus

Characins
8.5 cm Peaceful

A stunning, large schooling fish native to the Congo River basin. Known for their iridescent rainbow colors and active swimming behavior. Despite their size, they are notoriously peaceful and can be skittish, requiring ample swimming space, dim lighting or floating plants, and peaceful tank mates. Avoid keeping with fin-nippers.

Diamond Tetra

Moenkhausia pittieri

Characins
6 cm Peaceful

A stunning, deep-bodied tetra endemic to Lake Valencia in Venezuela. Named for the brilliant, iridescent scales on its flanks that sparkle like diamonds under the right lighting. They are highly active, peaceful schooling fish that thrive in well-planted aquariums. Males develop spectacular, flowing fins as they mature.

Ember Tetra

Hyphessobrycon amandae

Characins
2 cm Peaceful

The Ember Tetra is a striking, fiery orange-red nano fish native to the Araguaia River basin in Brazil. Extremely peaceful and active, they are perfect for planted and blackwater aquariums. They are tight schoolers and must be kept in groups to feel secure and display their best colors.

Emperor Tetra

Nematobrycon palmeri

Characins
5 cm Peaceful

A striking, robust schooling fish from Colombia. Unlike many tetras, they do not swim in a tight shoal, preferring to loosely associate while males stake out small territories to display to females. They feature a bold black lateral line and iridescent purple/blue hues.

Glowlight Tetra

Hemigrammus erythrozonus

Characins
4 cm Peaceful

A peaceful, schooling nano fish native to the Essequibo River basin in South America. They are famous for their translucent bodies and the striking iridescent neon-orange stripe running from snout to tail. They thrive in mature, planted aquariums with slightly soft, acidic water and subdued lighting.

Lemon Tetra

Hyphessobrycon pulchripinnis

Characins
5 cm Peaceful

A peaceful, deep-bodied schooling tetra known for its translucent yellow coloration and striking black and yellow fins. They are robust and active, making them an excellent choice for planted community aquariums. Their colors intensify significantly in a well-established tank with a dark substrate and proper schooling numbers.

Marbled Hatchetfish

Carnegiella strigata

Characins
4 cm Peaceful

A uniquely shaped, peaceful surface-dwelling characin famous for its deep, keeled belly and incredible jumping ability. In the wild, they can leap from the water and 'fly' short distances using their powerful pectoral fins to catch insects or escape predators. A tight-fitting lid with absolutely no gaps is mandatory. They require floating plants to feel secure and must be kept in schools.

Neon Tetra

Paracheirodon innesi

Characins
4 cm Peaceful

One of the most iconic freshwater fish in the hobby, famous for its striking iridescent blue and red stripes. Originally from the blackwater streams of the Amazon basin, they prefer slightly cooler water than many tropical fish and must be kept in schools to thrive, display natural behaviors, and feel secure.

Penguin Tetra

Thayeria boehlkei

Characins
6 cm Peaceful

An active schooling characin instantly recognizable by its bold black horizontal stripe that extends down into the lower half of the tail fin, and its unique, oblique (head-up) swimming posture. They are hardy and do well in community tanks, but must be kept in groups to prevent stress and fin-nipping behavior towards tank mates.

Red-Bellied Piranha

Pygocentrus nattereri

Characins
30 cm Aggressive

An infamous South American predator known for its razor-sharp teeth and schooling behavior. Despite their fearsome reputation, they are naturally skittish and easily spooked in aquariums, requiring a large shoal (4-6+) and dim lighting (often achieved via floating plants) to feel secure. They are incredibly messy eaters that produce extreme bioloads, necessitating massive filtration systems and frequent water changes.

Rummy-Nose Tetra

Hemigrammus rhodostomus

Characins
5 cm Peaceful

Renowned as the tightest schooling fish in the freshwater hobby. They feature a bright red nose, a silver body, and a black-and-white checkered tail. They are excellent 'indicator fish'; their red noses will fade to pale pink if water quality drops or the fish are stressed. While there are three very similar species (H. rhodostomus, H. bleheri, P. georgiae) often sold under the same name, their care requirements are identical.

Serpae Tetra

Hyphessobrycon eques

Characins
4.5 cm Semi-Aggressive

A striking, deep-red schooling fish known for its highly active nature. While hardy and beautiful, Serpae Tetras are notorious fin-nippers. This behavior is usually localized within their own pecking order if kept in large enough schools (8+), but they should never be housed with slow-moving or long-finned tank mates like Bettas, Angelfish, or Gouramis.

Silver Dollar

Metynnis argenteus

Characins
15 cm Peaceful

A large, peaceful schooling characin renowned for its laterally compressed, coin-like silver body. They are notorious herbivores that will devour almost any live plant in the aquarium. Highly skittish, they are known to dart rapidly when startled, requiring ample unobstructed swimming space and a tight-fitting lid.

X-Ray Tetra (Pristella)

Pristella maxillaris

Characins
5 cm Peaceful

A remarkably hardy and peaceful schooling fish, named for its translucent body that reveals its internal organs. Uniquely among tetras, it naturally inhabits both fresh and slightly brackish coastal waters in South America, making it incredibly adaptable to various aquarium conditions. An excellent choice for beginners.