Florida Flagfish

Jordanella floridae

Animalia›Chordata›Actinopterygii›Cyprinodontidae

📍 Florida, USA

Stunning killifish native to Florida whose flanks mimic the American flag. Hardy algae-eater that tolerates cool water. Great for subtropical and unheated tanks.

Size2.5"

Min Tank15g

School2+

semi-aggressive

Zonemid

Care Guide

Diet

Florida Flagfish are omnivores with a strong preference for algae and plant matter. Feed high-quality flake food or small pellets daily, supplemented 2-3 times weekly with blanched vegetables (spinach, zucchini) and algae wafers. They will naturally graze on algae in the tank, reducing the need for supplemental algae foods, but occasional frozen foods like bloodworms or brine shrimp can be offered as treats.

Behavior

These hardy killifish are semi-aggressive, particularly males which may display territorial behavior and fin-nipping tendencies toward smaller or slower-moving fish. They are active mid-water swimmers that prefer to school in small groups and spend considerable time grazing on algae-covered surfaces. They tolerate cool water well and are excellent algae controllers, making them valuable for planted tanks.

Breeding

Breeding Florida Flagfish in captivity is moderately difficult but achievable with proper conditioning. Pairs require dense vegetation or spawning mops, slightly acidic water (pH 6.5-7.0), and temperatures around 24-26°C. Females are prolific egg-layers, scattering eggs among plants; remove parents after spawning as they may eat fry. Fry are small and require infusoria or liquid fry food initially.

Tank Mates

Otocinclus

Peaceful algae-eater with similar water requirements; non-competitive for food

excellent

Emerald Dwarf Rasbora

Small, peaceful schooling fish that occupy different water zones and won't trigger aggression

good

Ramshorn Snail

Algae-eating snail that complements flagfish grazing; no competition or conflict

excellent

Least Killifish

Similar size and temperament; both are killifish with comparable water needs

good

Corydoras Duplicareus

Bottom-dwelling catfish that avoids competition; peaceful and compatible with cool-water conditions

good

Common Diseases

Ich (Ichthyophthirius multifiliis)

Symptoms

White spots on body and fins, rapid breathing, flashing against surfaces

Treatment

Raise temperature gradually to 28-29°C, use aquarium salt (1 tsp per gallon), and perform daily 25% water changes. Treat for 7-10 days; UV sterilization can assist in severe cases.

Fin Rot

Symptoms

Frayed or deteriorating fin edges, discoloration at fin bases, lethargy

Treatment

Improve water quality with frequent partial water changes, reduce aggression by adding plants/hiding spots, and treat with antibacterial medication if secondary infection occurs.

Velvet Disease (Oodinium)

Symptoms

Fine golden or rust-colored dust on body, clamped fins, rapid breathing, lethargy

Treatment

Increase aeration, raise temperature to 28-30°C, and use copper-free treatments or salt baths. Perform daily water changes and remove carbon from filters during treatment.

Bacterial Infection

Symptoms

Open sores, cloudy eyes, swollen belly, loss of appetite

Treatment

Isolate affected fish, maintain pristine water quality, and treat with broad-spectrum antibacterial medication. Ensure adequate nutrition and reduce stressors.