Half Beak

Species Profile

• Scientific Name: Dermogenys pusilla
• Common Name: Halfbeak
• Adult Size: 2.5–3 inches (6–7.5 cm)
• Life Expectancy: 2–5 years

• Habitat: Found in freshwater and brackish habitats across Southeast Asia, including slow-moving rivers, estuaries, and mangroves

Tank Requirements

• Minimum Tank Size: 15–20 gallons for a small group
• Ideal Temperature: 24–28°C (75–82°F)
• pH Range: 6.8–8.0
• Water Hardness: 10–20 dGH (moderately hard)
• Temperament: Generally peaceful, but males can be territorial and may show aggression toward each other; best kept in groups with a single male and multiple females

Diet & Nutrition

• Omnivorous: Yes
  • Eats small insects, insect larvae, crustaceans, and plant matter in the wild
  • In captivity, feed a mix of live or frozen foods (e.g. daphnia, brine shrimp), high-quality flakes, and small floating pellets

Appearance

• Coloration: Silvery body with occasional yellow or reddish markings on fins and snout
• Body Shape: Slender and elongated with a distinctively long lower jaw in males
• Sexual Dimorphism: Males are smaller, with longer lower jaws and more intense coloration

Distinctive Features

• Elongated lower jaw resembling a "half beak"—more pronounced in males
• Surface-dwelling fish that prefer the upper levels of the tank
• Viviparous (gives birth to live young)
• Sensitive to sudden changes in water conditions; requires stable water quality