Betta
Betta splendens
Betta splendens exhibits vibrant color variations, including iridescent blues and reds, with long flowing fins and a pronounced, aggressive demeanor.
This page includes AI-generated images. Why am I seeing AI images?
About the Betta
Betta fish, also known as Siamese fighting fish, are popular for their striking colors and flowing fins. They are known for their territorial nature, especially males, which can display aggressive behavior towards each other.
Quick Facts
Size
6.5 cm
Temperament
Semi-aggressive
Difficulty
Beginner
Min Tank Size
5 gallons
Lifespan
3-5 years
Origin
Southeast Asia
Diet
Carnivore - protein-rich foods, pellets, and live or frozen foods like bloodworms and brine shrimp
Water Parameters
24-30°C
6-8
5-19 dGH
Need a heater for this species?
This species needs 24-30°C in a 5 gallon tank. Use our heater calculator to find the right wattage.
Calculate heater sizeCare Notes
- Keep a single Betta in a heated, fully cycled aquarium of 5+ gallons (10+ is easier to maintain), with a tight-fitting lid (they jump) and low-to-moderate flow; use gentle filtration and add broad-leaf plants, caves, and floating cover for security and resting near the surface.
- Maintain stable warm water at 25-28°C (77-82°F) with pH ~6.5-7.5 and low-to-moderate hardness; avoid rapid temperature swings and aim for 0 ammonia, 0 nitrite, and nitrate ideally <20 ppm with weekly water changes (typically 20-40% depending on stocking and nitrate).
- Feed a Betta-specific pellet as the staple (small portions 1-2x daily, only what's eaten in ~1 minute) and supplement several times per week with frozen/live foods like brine shrimp, daphnia, or bloodworms; fast one day weekly or reduce portions to prevent bloating/constipation.
- House males alone-never with another male Betta and avoid most other long-finned or similarly shaped fish (guppies, fancy tetras) that trigger aggression; suitable tank mates in larger planted tanks include peaceful snails and shrimp (may be hunted) and calm schooling fish like ember tetras or rasboras if the Betta is not overly aggressive.
- Provide access to the surface for air breathing (labyrinth organ) and avoid strong surface agitation; keep décor smooth and plants soft to reduce fin tears, especially for long-finned varieties.
- Watch for fin rot (ragged, receding fins), ich/white spots, velvet (gold dusting, flashing), swim bladder/bloating, and stress signs like clamped fins or lethargy; these are often linked to poor water quality, cold water, or overfeeding-test water promptly and correct conditions before medicating.
- If breeding, use a separate breeding setup with shallow warm water and lots of floating plants for bubble-nest building; condition the pair on high-protein foods, remove the female after spawning, and be prepared to separate fry/juveniles as males become territorial.
Compatibility
Good Tankmates
- Small, peaceful schooling fish (species-dependent) may work in larger, well-planted tanks; avoid known fin-nippers and monitor for chasing/stress
- Bottom-dwelling scavengers like Corydoras catfish (especially smaller species) that ignore the betta and occupy different space
- Kuhli loaches and other peaceful, shy bottom fish that hide often and don't compete at the surface
- Otocinclus (in suitably sized, established tanks) may work; use caution with plecos because some can harass/slime-coat rasp slow fish and require larger tanks
- Snails (nerite, mystery) as low-conflict invertebrates; provide cover if the betta investigates
- Non-nippy shrimp with caution (e.g., adult Amano shrimp); heavy planting/moss helps reduce harassment
Avoid
- Other male bettas (and often multiple females without a carefully managed setup): high risk of fighting, stress, and injury
- Fin-nipping or boisterous fish (e.g., tiger barbs, serpae tetras, some danios): likely to shred betta fins and cause chronic stress
- Long-finned, betta-like fish that may trigger aggression (e.g., guppies, fancy male endlers, some gouramis/angelfish)
- Large aggressive/semi-aggressive fish (e.g., most cichlids) that can bully, outcompete, or injure a betta
Similar Species
Other freshwater semi-aggressive species you might be interested in.
American flagfish
Jordanella floridae
Jordanella floridae is that little Florida native with the red-and-cream striping that really does look like a tiny flag once a male colors up. They graze algae like champs (especially stringy/hair algae), but they have a bit of attitude - give them plants and space so the bossy behavior stays manageable. Bonus: the male guards the eggs and will actively fan them, which is pretty fun to watch.
Amur sculpin
Alpinocottus szanaga
This is a little coldwater sculpin from the Amur drainage - a bottom-hugging, rock-and-gravel fish that spends its day wedged under stones and darting out to grab food. Super cool behavior and attitude, but it is absolutely not a warm tropical community fish - it wants chilly, fast, oxygen-rich water and will bicker with other bottom fish.
Anitápolis livebearer
Jenynsia weitzmani
Jenynsia weitzmani is a freshwater anablepid livebearer endemic to southern Brazil (currently known only from the type locality near Anitápolis, Santa Catarina). Like other Jenynsia (onesided livebearers), reproduction involves lateralized mating morphology/behavior; aquarium care guidance is not well-documented for this species specifically.
Aracu-comum
Schizodon vittatus
Schizodon vittatus is a large South American anostomid (family Anostomidae). Reported maximum size is about 35 cm standard length; it is harvested/consumed in parts of Brazil and is not commonly covered by mainstream aquarium husbandry references.
Banded Leporinus
Leporinus fasciatus
Banded Leporinus are those torpedo-shaped, black-and-yellow striped fish that look like they're wearing a little prison outfit-and they stay on the move. They've got a ton of personality and they're awesome to watch cruising and picking at stuff, but they're also the kind of fish that will redecorate your tank and "taste test" anything soft-looking.
Bandi cichlid
Wallaceochromis signatus
Wallaceochromis signatus is a West African (Guinea, Kolente basin/Bandi River) dwarf cichlid that has appeared in the hobby under trade names such as “Bandi I/Bandi 1” and “Guinea” prior to/alongside its formal description. It is a cave-associated dwarf cichlid; provide cover and caves and expect heightened territoriality during breeding.
More to Explore
Discover more freshwater species.
Ajuricaba tetra
Jupiaba ajuricaba
Jupiaba ajuricaba is a South American freshwater characin from the Amazon basin in Brazil (rio Negro, rio Solimões, and rio Tapajós basins). It reaches about 9.5 cm SL and is diagnosed by a narrow dark midlateral stripe, an elongated humeral spot, and an ocellated spot on the upper caudal-fin lobe. Wild specimens have been collected from blackwater forest streams and also oxbow-lake habitats.
Amapa tetra
Hyphessobrycon amapaensis
This is a tiny, super sleek little tetra with a clean red stripe down the side that really pops once its settled in. It does best in a planted, slightly tinted "creek-style" setup and looks way cooler when you keep a proper group so they school and flash that line together. If you can give it soft, slightly acidic water and a calm community, its an easy fish to fall for.
Anteridorsal Homatula loach
Homatula anteridorsalis
This is a benthic Chinese stream loach from Yunnan that lives right down on the bottom in clear, flowing water over gravel and rocks. Think of it as a "river tank" fish - it wants current, oxygen, and lots of surfaces to poke around on for bits of food and algae.
Armoured stickleback
Indostomus paradoxus
This is that goofy little "freshwater seahorse"-looking fish that just kind of perches and scoots around like a tiny armored twig. Its whole vibe is slow, sneaky micropredator - once its settled in, you will catch it stalking microfoods and doing these subtle little posture displays. The big trick is feeding: they do best when you can provide lots of small live foods in a calm, planted tank.
Arnegard's electric fish
Petrocephalus arnegardi
This is a little Congo River elephantfish (a weakly electric mormyrid) that cruises the lower parts of the tank and navigates the world with its electric sense. It stays small (around 9 cm) and has a clean silvery look with three dark marks that make it pretty easy to pick out among Petrocephalus.
Aroa twig catfish
Farlowella martini
Farlowella martini is one of those unreal-looking stick catfish that just vanishes the moment it parks itself on a branch. It is a super calm, slow-moving grazer that does best in a mature tank with lots of biofilm, gentle flow, and clean, oxygen-rich water - they are not great at competing at feeding time, so you kind of have to look out for them.
Looking for other species?