FishbeginnerFreshwater

Halfmoon Betta

Betta splendens 'Halfmoon'

Animalia›Chordata›Actinopterygii›Osphronemidae

📍 Thailand & Cambodia

The Halfmoon Betta is one of the most recognisable and popular betta cultivars, characterised by the spectacular 180-degree spread of the caudal fin that forms a perfect half-circle when fully flared. Selective breeding has produced individuals with extraordinary fin size and vivid coloration in virtually every hue. The large fins require pristine water quality to prevent fin rot and tearing.

Size2.5"

Min Tank5g

semi-aggressive

Zonetop

Care Guide

Diet

Halfmoon Bettas are strict carnivores and require high-protein foods. Feed quality betta pellets as a staple (once daily in small portions), supplemented 2-3 times weekly with frozen bloodworms or brine shrimp. Avoid overfeeding, which causes bloating and water quality issues; feed only what they consume in 2-3 minutes.

Behavior

Halfmoon Bettas are highly aggressive toward other males and will fight to the death if housed together. They are solitary, territorial fish that spend time at the water surface and mid-water levels, displaying elaborate fin flaring when stressed or establishing dominance. Males are more aggressive than females, though females can also be territorial.

Breeding

Breeding Halfmoon Bettas in captivity is moderately difficult and requires careful conditioning and monitoring. Males build bubble nests and will guard fry aggressively; females must be removed after spawning to prevent aggression. Fry require infusoria or liquid fry food for the first week before graduating to micro pellets.

Tank Mates

Otocinclus

Peaceful bottom-dweller that won't trigger aggression; requires similar water parameters

good

Ramshorn Snail

Non-threatening invertebrate; helps with algae control without competing for space

good

Nerite Snail

Peaceful scavenger that occupies different zones; minimal interaction with betta

good

Ember Tetra

Small, fast-moving fish may trigger chase response; only in larger 10+ gallon tanks with dense plants

caution

Ghost Shrimp

May be viewed as prey; only suitable if betta is well-fed and tank is heavily planted

caution

Common Diseases

Fin Rot

Symptoms

Fraying, discoloration, or deterioration of fin edges; often starts at tips and progresses toward body

Treatment

Perform 25-50% water changes every 2-3 days, maintain pristine water quality (0 ammonia, <20 ppm nitrate), and consider antibacterial medication (e.g., Maracyn) if bacterial infection is suspected

Ich (Ichthyophthirius multifiliis)

Symptoms

White spots resembling salt grains on body and fins; lethargy, loss of appetite, rapid gill movement

Treatment

Raise water temperature gradually to 28-30°C, perform daily 25% water changes, and treat with ich medication (e.g., methylene blue or copper-based treatments) following product instructions

Velvet (Oodinium)

Symptoms

Fine golden or rust-colored dust on body, clamped fins, rapid gill movement, lethargy

Treatment

Increase temperature to 28-30°C, perform frequent water changes, reduce light exposure, and use velvet-specific medication or salt treatment (1 teaspoon per gallon) as directed

Dropsy

Symptoms

Swollen abdomen, scales standing out (pinecone appearance), lethargy, loss of appetite

Treatment

Isolate in a hospital tank, perform frequent water changes, feed high-quality foods, and consider antibacterial medication; prognosis is often poor if advanced