Jordanella  floridae  - Flagfish

Described by: Goode & Bean, 1879    

Named for: David Starr Jordan, the first president of Stanford University. He was a renowned American zoologist and ichthyologist who specialized in American fish The species name refers to where it’s mainly found.

Family:    Cyprinodontidae (Pupfishes), subfamily: Cyprinodontinae

Order:   Cyprinodontiformes (rivulines, killifishes and live bearers)  

Common Name:  Flagfish; American Flagfish

Synonyms: Cyprinodon floridae

Size: Males can reach 2 ½ -3” (6-7.6 cm), females get only about 2/3 of this size.

Sexing: Sexually dimorphic. Females have a spot on the back of their dorsal and on their sides that males do not. Males have a brilliant red-orange colour on their sides. The male loses his dorsal spot as he matures

Locale: North America; along the Gulf Coast (mainly Florida). They are found in slow moving waters such as swamps, ponds, lakes and ditches.

Flagfish prefer a temperature of 18 - 22°C (64-71°F).

Since flagfish are so unique, they have been identified as cichlids and sunfish. In fact, they are pupfish (a branch of the killifish family), with their own genus. In fact, Jordanella sometimes act as if they are cichlids. They are very tolerant of differing conditions, and will even breed in water conditions that you wouldn’t expect. Flagfish are a great beginner killifish.

Flagfish do well on a diet of algae and other greens. In fact, if they aren’t fed well enough, they’ll start eating your aquarium plants. They enjoy insects as well. So a well rounded flake diet including some protein and vegetable matter should be given to these fish.

There are several methods of spawning in these fish which has led to some confusion among hobbyists. Generally, this has to do with what sort of “habitat” is available to them. If they are kept in deeper tanks or ponds, they tend to lay their eggs near the surface if possible. Generally, if there is too much current near the surface they will spawn deeper in the tank. As far as I can find, they do not tend to spawn on the bottom. If they are in a shallow tank, Jordanella floridae the male will guard the eggs and fan them. They are not laid on the bottom directly, but on plants or algae near the bottom of the tank.

It’s believed that the young do not develop properly if they are trapped in too deep water. This fits in with how the flagfish try to spawn near the surface since it means the fry should develop in shallower water (e.g. along the shoreline). They are also spawned using the typical killifish trick of using a spawning mop.

The habit of flagfish to eat algae is a good one in an aquarium. They will keep algae under control. Personally, I keep my flagfish out in my pond during the summer and place them in a tank for the winter months. I don’t feed my pond except at the beginning of the year when there’s not a lot of food available yet. I usually end up with more fish than I started with. The first year I placed Jordanella outdoors, I ended up with about 15 young and the original 6 fish I placed into the pond. The pond is only 150 gallons so I don’t expect large numbers of fish. The year after that, I ended up with over 30 young and the original parents again. The third year was a bit different though. I only came up with two of the original 3 males, and none of the original females. However, I did come up with 2 females from the second year. I also got a bunch of fry. Some were so small I had to raise them separately for a while so they could get some size on them so they could go in the bigger tank with the rest of the flagfish. While the flagfish are inside they are on a diet of flakes, and treats of baby brine shrimp. They are absolutely stunning in colour and I don’t see why more people don’t keep them in tanks.

© Copyright 2004 Lisa Boorman
All Rights Reserved

Suggested Reading:

American Aquarium Fishes (W.L. Moody, Jr., Natural History Series, No 28)

North American Native Fishes for the Home Aquarium

Rare and Endangered Biota of Florida: Vol. II Fishes

To see other references on killfish or native North American fish:

Native American Fish Book List

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