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.
Florida Flagfish At a Glance
Florida Flagfish Tank Requirements
Will Florida Flagfish fit in your tank?
Care guides tell you what Florida Flagfish needs, the next question is whether your tank can safely provide it. Test Florida Flagfish against your tank size, maintenance needs, and the fish you already keep before you buy.
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Florida Flagfish Water Parameters
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Florida Flagfish Temperament & Compatibility
Florida Flagfish 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 Guide 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.
The Florida Flagfish is a rewarding species to keep, provided its core environmental needs are met. 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.
Florida Flagfish Habitat Setup
When setting up an aquarium for the Florida Flagfish, a low water flow best suits their natural preferences. Because this species occupies the mid-level and bottom zones, the aquarium layout should prioritise open swimming space in the centre of the tank for free movement and sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include an established tank with natural algae growth, as they depend on it as a primary food source and dense planting to provide cover, break sightlines, and reduce stress.
Florida Flagfish Compatibility Notes
Classified as semi-aggressive, the Florida Flagfish is adaptable and can be kept singly or in a small group, offering flexibility when planning a community tank. When choosing tankmates, avoid housing with slow-moving or long-finned species that may become targets for fin nipping, conspecific aggression can be intense, especially in smaller tanks, territorial behaviour may cause issues if hiding spots or floor space are limited, and their energetic swimming style may stress more sedentary or timid species. Selecting tankmates that favour different water layers from the mid-level and bottom zones can help reduce competition and territorial overlap.
Florida Flagfish Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Florida Flagfish.
20 Gallon High
20 Gallon Long
29 Gallon Standard
30 Gallon Breeder
36 Gallon Bowfront
40 Gallon Breeder
Show 17 more tank sizes
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Frequently Asked Questions About Florida Flagfish
How big does Florida Flagfish get?
Florida Flagfish (Jordanella floridae) typically reaches a maximum adult size of approximately 6 cm. They have a compressed body shape and a moderate growth rate.
What tank size does Florida Flagfish need?
A minimum aquarium volume of 75 litres and a tank length of at least 60 cm are recommended for Florida Flagfish. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Florida Flagfish need?
Florida Flagfish thrives in brackish tolerant conditions with a temperature range of 18–26°C, a pH between 6.5 and 8.5, and a general hardness of 10–25 dGH. A low water flow is preferred.
Is Florida Flagfish peaceful or aggressive?
Florida Flagfish is classified as semi-aggressive with an aggression score of 5 out of 10. They can work in community setups but may clash with certain tankmates.
Can Florida Flagfish live alone?
Yes, Florida Flagfish can be kept singly or in a group. They are flexible and adapt well to both setups.
Does Florida Flagfish have any special tank requirements?
Yes. Florida Flagfish benefits from established algae (otocinclus) and plants - densely covered in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Plants That Suit Florida Flagfish
These plants pair well with Florida Flagfish based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
Amazon Frogbit
Limnobium laevigatum
Asian Watergrass
Hygroryza aristata
Asian Watermoss
Salvinia cucullata
Beckett's Water Trumpet
Cryptocoryne beckettii
Broad-leaved Crypt
Cryptocoryne pontederiifolia
Carolina Fanwort
Cabomba caroliniana
Fish Similar to Florida Flagfish
Flagtail Prochilodus
Semaprochilodus insignis
A large, highly active South American river fish famous for its vividly striped tail and prolific algae-eating habits. They are a staple 'cleaner' in large monster fish setups alongside Arowanas and Stingrays. While peaceful towards other large species, they are fiercely intolerant of their own kind unless kept in large shoals. They are notorious plant destroyers.
Flagtail Cory (Mrs Schwartz's Cory)
Corydoras robineae
The Flagtail Corydoras is a striking and highly sought-after bottom dweller native to the Rio Negro basin. Characterized by the distinct black and white horizontal stripes on its caudal fin, it requires a soft sand substrate to protect its delicate barbels while foraging. Like all Corydoras, it is a highly social schooling fish and must be kept in groups to feel secure and display natural behaviors.
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.
Bearded Cory
Scleromystax barbatus
A large, striking, and somewhat atypical relative of standard Corydoras. Native to the highly oxygenated, cooler coastal streams of Brazil, they require sub-tropical temperatures and will stress or die in standard tropical tanks. They exhibit strong sexual dimorphism. Highly social, they must be kept on a soft sand substrate to protect their sensitive barbels.
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.