American Flagfish

American Flagfish key facts

Care level

Intermediate

Lifespan

3-5 years

Size

5.5-6.5cm

Temperature

18〜30℃

Diet

Filamentous algae, Artemia, Daphnia, vegetable-based dried foods

Tank

Seriously Fish suggests a 60 x 30cm base of about 54 litres. Break lines of sight with plants or wool mops, and allow filamentous algae to grow.

Water Temperature & Quality

Seriously Fish gives a wide range of 18-30C, pH 6.5-8.5 and 2-20dGH. FishBase records 18-22C in the wild, so it tolerates cool water.

Tank Mates

Seriously Fish states it is not a community fish and recommends keeping it alone. Males hold territories, but two or more can share a tank if there is enough space.

Diet & Feeding

It hunts small crustaceans and worms but also eats filamentous algae and plant matter. Offer Artemia and frozen foods alongside dried foods with algal or vegetable content.

Breeding & Spawning

It is a fractional spawner, attaching eggs a few at a time to algae and other surfaces by fine filaments. Sources disagree on parental care: FishBase states that males guard the eggs, while Seriously Fish denies that it digs pits or shows extended parental care.

Health & Notes

FishBase describes it as easy to maintain. A short-bodied balloon strain is also sold, and buyers should understand that it is a line-bred deformity. The IUCN has not evaluated the species.

About American Flagfish

A hardy Florida-native killifish with red and pale stripes resembling the American flag. It readily eats thread algae and suits intermediate keepers, though territorial males need space and cover when housed with others.

7 things to know before welcoming a American Flagfish

1. 1How It Got Its Name

   The red and pale stripes running along its body are reminiscent of the American flag, which is how this fish got its name. Coloring becomes more distinct as the fish matures, so young and adult fish can look quite different.

2. 2Territorial Males

   Males stake out territory and often bicker if more than one is kept in the same tank. When housing them with tankmates, provide a spacious tank along with plants or driftwood that break up sightlines.

3. 3Algae-Eating Habits

   They have a strong appetite for thread algae and are sometimes kept partly for algae control. That said, they still need some plant matter in their diet, so avoid relying on prepared foods alone.

4. 4Choosing Tankmates

   Because males can be assertive, calmer fish of a similar size make better companions. Long-finned or timid, small fish are best avoided, as they may end up being chased.

5. 5Adult Size

   Adults grow to about 5.5 to 6.5 cm in length. As they fill out, it's worth keeping even a single fish in a reasonably sized tank so it has room to swim comfortably.

6. 6Spawning and Male Guarding

   As an egg-laying killifish, males may guard the area around the spawning site. If you're hoping to breed them, provide plants or moss where eggs can be laid.

7. 7Getting Ready Before You Bring One Home

   They're hardy and easy to keep overall, but success comes down to planning your tank layout around the male's temperament. Have plants or hiding spots ready before your fish arrives so it can settle in comfortably.

Frequently asked questions about American Flagfish

Q.Can beginners keep this fish?

A.This species is considered suitable for intermediate keepers, so some basic knowledge of water quality management and tankmate compatibility is helpful. They're hardy, but you'll still need to plan your setup around the male's temperament.

Q.Can it be kept with other fish?

A.Community tanks are possible, but care is needed because males are territorial. Giving the tank extra space and adding plants or decor that break up sightlines helps keep things calm.

Q.Can it be kept for algae control?

A.Because they readily eat thread algae, they're sometimes added specifically for algae control. Still, remember to offer a balanced diet that includes some plant matter.

Q.How big do they grow?

A.Adults reach about 5.5 to 6.5 cm in length. That makes them somewhat larger than many other small aquarium fish.

Q.Can they be bred at home?

A.As egg-laying killifish, breeding at home is possible. Males may be seen guarding the area around the spawning site, so it helps to provide plants or similar material where eggs can be laid.

Useful tools for American Flagfish care

Learn more about American Flagfish in the encyclopedia

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