TankBud

American flagfish

Jordanella floridae

Also known as Florida flagfish, Florida flag fish

FreshwaterFish

American flagfish (Jordanella floridae)
"Florida Flagfish (Jordanella Floridae)" by CheepShot is licensed under CC BY 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by/2.0/. · by

Care at a glance

Temperature
63–73°F
17–23°C
pH
7.0–8.0
Adult size
2.2 in
5.5 cm
Minimum tank
18 gal
70 L
Temperament
Mostly peaceful
Social behavior
Social
Tankmates
With caution
Swim level
Middle
Diet
Omnivore
Difficulty
Easy
Breeding
Substrate spawner · Hard
Rarity
Rare
Family
Cyprinodontidae
Origin
Florida

Overview

The American flagfish is a mostly peaceful killifish that grazes algae in a well planted, cooler tank. It is an easy fish for a beginner.

Did you know

The male American flagfish takes on guard duty after spawning, hovering over the eggs and fanning them with his fins. This keeps the eggs clean and oxygenated until they hatch. Paternal care like this is unusual among the egg-scattering killifish.

Caring for the American flagfish

Keep a small group of American flagfish in a tank of 18 gal (70 L) or larger, which gives them space to spread out. A densely planted tank with plenty of algae to graze suits them. Add a soft substrate, some leaf litter or spawning mops and gentle flow.

As subtropical natives, they prefer cooler water than most killifish, at 63 to 73°F (17 to 23°C). They can be kept without a heater in most homes. Keep the pH at 7.0 to 8.0.

American flagfish are among the few killifish that lean strongly herbivorous. Base the diet on algae, biofilm and blanched vegetables, topped up with occasional daphnia, bloodworms or brine shrimp. They graze across the lower and middle levels of the tank.

They are mostly peaceful, though their tank mates should be chosen with caution. Males set up small territories and can chase each other, so give them room and floating cover to break up sight lines.

They are fractional spawners that breed over an extended warm spell, unlike annual killifish with drought-resistant eggs. Females scatter eggs into plants or a shallow pit in the substrate, and the male guards the clutch. The fry emerge after about a week. Rearing the fry and managing the male's territorial streak make consistent breeding a genuine challenge.

Good to know

American flagfish belong to the pupfish family Cyprinodontidae. Stocky males show the red and blue barring that gives the fish its flag-like name.

In the wild

American flagfish live in warm, slow, heavily vegetated waters across Florida, from ponds and ditches to the quiet margins of marshes and canals. The water there is often soft to moderately hard and close to neutral or slightly alkaline.

Common questions

What size tank does an American flagfish need?

An American flagfish needs at least 18 gal (70 L). It spends most of its time in the middle.

What temperature and pH does an American flagfish need?

An American flagfish is comfortable at 63–73°F (17–23°C) with a pH of 7.0–8.0.

What does an American flagfish eat?

An American flagfish eats mostly algae, biofilm and blanched vegetables. Top this up with occasional daphnia, bloodworms or brine shrimp.

How big does an American flagfish get?

An adult American flagfish reaches about 2.2 in (5.5 cm).

How does an American flagfish breed?

American flagfish are fractional spawners that breed over an extended warm spell. Females scatter eggs into plants or a shallow pit, and the male guards the clutch until the fry emerge after about a week. Consistent breeding is a genuine challenge.

Related species