Description

Species Background

Florida Flagfish (Jordanella floridae) are a freshwater killifish native to the state of Florida. They are found in canals, marshes, slow-moving streams, and vegetated waters where algae growth is abundant year-round. Unlike many killifish species associated with temporary pools, Florida Flagfish are fully adapted to permanent freshwater environments and experience natural fluctuations in temperature and water chemistry.

Behavior and Temperament

Florida Flagfish are active, alert fish that spend much of their time moving through the tank and interacting with their surroundings. They may establish small territories, particularly in open areas, but are commonly kept successfully in community aquariums. Tank layout, plant density, and stocking choices play a larger role in compatibility than the species itself.

Adult Size

Adults typically reach 2.5–3 inches in length.

Water Parameters

These ranges reflect modern husbandry data and long-term aquarium success.

• Temperature: 64–78°F

Florida Flagfish (Jordanella floridae) are attractive, active freshwater killifish known for eating black beard algae and green hair algae. Hardy and adaptable, they do well in planted aquariums with stable conditions.

• pH: 6.5–8.2
• GH: 6–20 dGH
• KH: 4–15 dKH

Stable conditions are prioritized over targeting a specific number.

Diet

Florida Flagfish are omnivores with a strong preference for algae and plant matter. They are one of the few aquarium fish known to eat black beard algae and green hair algae, along with other surface growth and biofilm. A balanced diet should include spirulina-based flakes, algae wafers, blanched vegetables, and supplemental protein foods such as frozen brine shrimp or insect-based granules.

Tank Requirements

A minimum 20-gallon aquarium is recommended. Tanks should include live plants, driftwood, and hardscape to provide structure and grazing surfaces. Moderate filtration with consistent maintenance supports long-term health.

Why They’re Popular

Florida Flagfish are popular because they combine attractive appearance, active behavior, and practical algae consumption. They are a hardy North American species that adapts well to planted aquariums while offering benefits beyond appearance alone.