A robust, deep-bodied killifish native to Florida. Unlike most killifish, they are primarily herbivores and are renowned for their ability to eat Hair Algae and sometimes Black Beard Algae. They are sub-tropical and thrive in unheated aquariums. They can be fin-nippers, especially if underfed or kept with long-finned tank mates.
At a Glance
Tank Requirements
Water Parameters
Temperament & Compatibility
Available Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Male
The colorful sex featuring rows of red and green scales resembling a flag. Males are territorial, especially when guarding eggs. Best kept as a single male with multiple females or in a large group.
Differs in 2 traits from base species
Also known as: Standard
Female
Plumper and less colorful, distinguished by a clear dark spot on the dorsal fin (the 'ocellus'). Generally less aggressive than males but still capable of fin-nipping slow fish.
Differs in 2 traits from base species
Florida Flagfish Care Summary
The Florida Flagfish, scientifically known as Jordanella floridae, belongs to the Killifish family group. Adults reach a maximum size of approximately 6 cm and have a compressed body shape with a moderate growth rate. Classified as semi-aggressive, this species primarily occupies the mid-level and bottom zones of the aquarium and produces a medium level of biological waste.
To thrive, the Florida Flagfish requires a brackish tolerant aquarium with a minimum volume of 75 litres and a tank length of at least 60 cm. Water temperature should be maintained between 18°C and 26°C, with a pH range of 6.5–8.5 and a general hardness of 10–25 dGH. A low water flow is preferred. To replicate their natural habitat, the tank should include established algae (otocinclus) and plants - densely covered.
Florida Flagfish can be kept singly or in a group, making them flexible additions to most setups. Keepers should be aware that this species may nip the fins of slow-moving or long-finned tankmates, can be aggressive toward its own kind, and will defend a territory within the tank. This species is available in 2 varieties: Male and Female. Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.
Similar Species
Gardner's Killifish
Fundulopanchax gardneri
A stunning, semi-annual killifish native to Nigeria and Cameroon. Known for being relatively hardy and an excellent 'beginner' killifish. They are notorious jumpers and require a tightly fitting lid. While they can be kept in community tanks with similarly sized, fast-moving fish, males can be boisterous and territorial.
Clown Killifish
Epiplatys annulatus
A striking nano killifish resembling a tiny rocket. Native to West African swamps, they have distinct black and yellow vertical bands. They are strictly surface dwellers (top-level) and are non-annual, meaning they live longer than annual killifish (2-3+ years). They are notorious jumpers and require a tight lid.
Clown Knifefish
Chitala ornata
A massive, nocturnal predator native to Southeast Asia, widely known for the distinct row of ocellated spots above its anal fin. While sold as small silvery cute juveniles, they grow incredibly fast into nearly 1-meter giants that require immense aquariums. They are obligate carnivores and will eat any fish small enough to fit in their large mouths. They are shy during the day and require large hiding tubes or caves.
Golden Wonder Killifish
Aplocheilus lineatus
A large, incredibly hardy, surface-dwelling killifish. The 'Golden Wonder' is a selectively bred bright yellow morph of the wild Striped Panchax. They are notorious predators with surprisingly large, trapdoor-like mouths; they will easily consume neon tetras, guppies, and dwarf shrimp. They are completely peaceful with fish too large to eat, but require a tight-fitting lid as they are expert jumpers.
Siamese Algae Eater
Crossocheilus oblongus
Famous for being one of the few freshwater fish that actively consumes Black Beard Algae (BBA). A torpedo-shaped, active bottom-to-midwater swimmer native to Southeast Asian streams. True Siamese Algae Eaters feature a distinct black horizontal stripe that extends all the way through the tail fin. As they mature, they can become lazy, preferring prepared foods over algae, and may occasionally chase other bottom dwellers.
Platy
Xiphophorus maculatus
A quintessential community fish known for its durability and massive variety of colors. Native to Central America, Platies are livebearers, meaning they give birth to free-swimming fry. They are peaceful, active grazers that require hard, alkaline water to thrive. They are excellent for beginners but breed prolifically.