Not furry, but we like them anyway.

American Flagfish

Jordanella floridae

Also called Flagfish, Florida flagfish

SpeciesShort profile

From Peninsular Florida, USA, from the St. Johns and Ochlockonee river drainages southwards.1 2 3

At a glance the quick version

Length5.5 to 6.5 cm1 2 3

Sizesmall

Hardy fish that copes with a wide temperature range

Happily grazes on hair algae

Males show a striking flag-like pattern

1 3

Looks how to spot one

Short, stocky scaled fish

A sturdy little killifish with a blunt, bulldog-like snout. Adult males carry longer dorsal and anal fins than females, while females are rounder and show a dark spot towards the back of the dorsal fin.1 3

Coloursolive basered and pale horizontal stripes (males)dark shoulder patchturquoise scales (females)3 1

Personality what they are like

An active, fairly robust fish. Males claim small territories, but several can share a roomy tank. Often happiest in a species tank, though it can join a spacious community.1

Daily activity how busy a day looks

Moves around plants and open water through the day; give it room so males can each hold a patch.1

Grooming and care the hands-on bits

Temperature around 18-30 C, pH 6.5-8.5, hardness 2-20 dGH. Unheated tanks at room temperature are often fine within this range.1 2

Home where they are happiest

At least a 60 x 30 cm footprint (about 54 litres), more for groups. Plenty of plants and a gentle flow, copying the shallow weedy marshes and ditches it comes from.1 3

Food basics what goes in the bowl

Omnivore. Eats small invertebrates and also plant matter and algae. Offer quality dried food plus live or frozen daphnia and brine shrimp, and some vegetable-based food if algae is scarce.1 2 3

Company who they like around

Can be kept singly or in small groups; give males space and visual barriers.1

The story where it all began

Goode and Bean described the species in 1879 from Lake Monroe, Florida. The genus honours ichthyologist David Starr Jordan, and the fish has been a long-standing favourite in the aquarium hobby.3 1

Fun facts for the dinner table

1
It earns its name from the dominant male's pattern, which looks a bit like the US flag with a dark 'stars' patch and red stripes.3
2
It is noted for laying very few eggs, around 20 over several days.2
3
Aquarists value it as one of the few fish that will eat hair algae.3
4
Sources differ on parenting: FishBase describes males guarding and fanning eggs, while Seriously Fish reports no lasting parental care.1

Recognised by the official bits

FishBase: Listed as Not Evaluated by the IUCN.2
Guinness World Records (via FishBase and Wikipedia): Cited for laying the fewest eggs of any fish, about 20 spread over several days.2

The care rhythm a typical week and year

A typical home-care rhythm for an American Flagfish. A starting point, not a vet's advice.

FeedingSmall amounts once or twice a dayevery day
Temperature checkevery day
Water changeAbout 25% of the waterevery week
Water testevery week
Glass cleanevery week
Filter rinseRinse in old tank water, never tap waterevery month

Owner questions the things everyone asks

How often should I feed my American Flagfish?

Feed your American Flagfish small amounts once or twice daily. Furry Diary's starting plan suggests daily feeding. This active omnivore will appreciate regular meals.1 2 3 Pet Wiki plan

What does an American Flagfish eat, and what should it never eat?

It eats small invertebrates, algae, and plant matter. Offer quality dried food plus live or frozen daphnia and brine shrimp, and vegetable-based food if algae is scarce. Avoid any foods not meant for fish; for specific restrictions, ask a vet or good breeder.1 2 3

How much space does an American Flagfish need?

A single American Flagfish needs at least a 54-litre tank with a 60x30 cm footprint. For groups, provide more space and plenty of plants to create territories.1 3

What temperature, light or water does an American Flagfish need?

Keep water temperature between 18-30°C, pH 6.5-8.5, and hardness 2-20 dGH. Unheated tanks at room temperature often work well. Provide plenty of plants and a gentle flow, mimicking its natural marsh habitat.1 2

How often should I clean an American Flagfish's home?

Change about 25% of the water weekly and clean the glass at the same time. Rinse the filter monthly in old tank water, never tap water. Furry Diary's starting plan recommends this routine. Pet Wiki plan

Can an American Flagfish live with others?

Yes, it can live with others in a spacious tank with visual barriers. It is often happiest in a species tank but can join a peaceful community. Males may claim small territories, so give them room.1

How long does an American Flagfish live?

Lifespan varies depending on care and environment. For a typical lifespan, ask a good breeder or an exotic-pet vet.

Can I handle an American Flagfish?

Handling is not recommended; fish are delicate and should remain in water. If you must move it, use a soft net gently. Always prioritize its well-being.

Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Pet Wiki's own starting care plan. A friendly guide, not a vet's advice.

Medaka

Norman's Lampeye

Where this comes from

Every fact on this page has a numbered source. Spotted an error? support@petwiki.app.

Seriously Fish: Jordanella floridae seriouslyfish.comused for size, range, care parameters, behaviour, diet
FishBase: Jordanella floridae fishbase.seused for size, range, egg count, IUCN
Wikipedia: Flagfish en.wikipedia.orgused for description, colours, history, fun facts

Checked 2026-09-30. Text is written in our own words from these sources.