Max Size: 7cm

American Flagfish (Jordanella floridae)

The American Flagfish are reasonably peaceful apart from when they are nesting. They can become very territorial even towards the female, and individuals can also be bad-tempered fin-nipping bullies. Therefore, if you keep them in a community aquarium, you will need a relatively large and spacious one with plenty of hiding places; this should limit any problems if they choose to spawn.

Any aggression is generally aimed towards their own kind. Still, if these fish are given sufficient room and have plenty of visual barriers amongst the plants and decor, this should not become an issue.

American Flagfish is best kept in a species only aquarium; however, if you do choose to house them with other fish, then their tankmates should be of similar temperament and size and will need to be able to live in the same cooler, slightly alkaline conditions as the Flagfish.

Flagfish are small, hardy, robust fish with a lopped snout that has been compared to that of a bulldog. They have rounded fins with the anal and dorsal fins positioned posteriorly and adjoining the caudal fin. Females have a prominent spot on their flanks and a transparent spot near the posterior end of the dorsal fin; this has an opaque white margin.

The fins may show a slightly reddish colour, but this can come and go in individuals, although the reason for this is unknown. The female's body is mainly olive, just marked with turquoise scales.

The American Flagfish get its name from the male during the breeding period due to the remarkable resemblance of the stars and stripes on the United States flag. The male also has a dark spot positioned at the lower rear corner of the dark rectangle.


American Flagfish Male
Male American Female
Male American Female
Female American Flagfish
Quick Facts
Scientific NameJordanella floridae
Other NamesFlagfish, Florida Flagfish
Aquarium LevelMiddle - Top
DifficultyBeginner - Intermediate
Best kept asTrios
Lifespan2 - 3 years
Water Parameters
Water TypeFreshwater
PH6.5 - 8.5
GH5 - 20
TDS36 - 357
64 - 86℉
17.8 - 30℃


In the home aquarium, the American Flagfish will readily accept most good quality dried foods such as granules, flakes and sinking pellets. These modern food products have been developed to provide all adequate nutrition to maintain your fish's health and dietary requirements.

Providing additional foodstuffs such as live, frozen, and freeze-dried meals such as bloodworm, daphnia, and tubifex once or twice a week will provide additional benefits to your fish's health and well-being but is not a must for this fish.

It should be noted that bloodworms should only be given as an occasional treat and should not be used as the staple diet as they are difficult for fish to digest and can potentially cause blockages.

This fish is an omnivore in the wild, meaning it will consume some vegetable matter. Although most modern fish foods take this into account and include them in their products, you can still supplement your fish's diet with blanched vegetables such as spinach, broccoli, and zucchini. Ensure you do not overfeed your fish and remove any leftovers the following day.

Sexual Dimorphism

It is pretty easy to differentiate between male and female American Flagfish. Adult males hold more extended anal and dorsal fins and are significantly more colourful than females, more so when in spawning condition. In contrast, adult females are typically rounder-bellied than males, especially when gravid, and occupy a dark blotch on the posterior part of the dorsal fin that is not present in males.

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Date Added: 05/05/2021 15:00:55 - Updated: 19/01/2022 14:32:34