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
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Water Parameters
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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
Top Tank Mates
Wrestling Halfbeak
Dermogenys pusilla
🟢Ideal Tank MatesJapanese Ricefish (Medaka)
Oryzias latipes
🟢Ideal Tank MatesPenguin Tetra
Thayeria boehlkei
🟢Ideal Tank MatesDiamond Tetra
Moenkhausia pittieri
🟢Ideal Tank MatesEmperor Tetra
Nematobrycon palmeri
🟢Ideal Tank MatesBleeding Heart Tetra
Hyphessobrycon erythrostigma
🟢Ideal Tank MatesFlorida 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. An aquarium test kit can help you monitor these values.
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.
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
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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.
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