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Jordanella floridae
Goode and Bean, 1879 The American-Flag Fish

© Wright Huntley, Author.
June 1995


Santa Clara, CA


Described by Tutaj as "An American Beauty," this strikingly lovely and peaceful algae eater deserves a better break.

Of the hundreds of species of killies kept and propagated by dedicated specialists, very few qualify as a suitable fish for the more casual aquarist. The American-Flag fish, Jordanella floridae is a notable exception. Misunderstood, improperly identified, and frequently described inaccurately in the general aquarium literature, this pupfish deserves a place in many community tanks that it has been denied by an undeserved reputation. While consuming algae like the best Siamese Algae Eater, it is beautiful, rugged and extremely tolerant of varied water conditions. Highly prized in Europe, maybe it’s too close to home, here, for proper appreciation. Recently priced at less than $3.00 in local stores, it is a colorful bargain when it matures.

Originally thought to be a cichlid, this native of the gulf coast, but primarily Florida, also was identified with the sunfish. Now known as a unique, single-species genus of native American pupfish, it has uncanny behavioral resemblance to both the sunfish and cichlid groups. The spiny dorsal ray is unique among Cyprinodontidae. The only time the Jordanella floridae shows belligerence, above that of a molly, is during courtship and when guarding eggs. At that time, the female, or any territorial invader, is at real risk from an irate male, who can do serious damage. This is no different than almost any nesting cichlid or gourami.

The generic name is for David Starr Jordan, the first president of Stanford University. The species name is for the state where it is most prevalent. The habit of shipping wild specimens from selected gathering grounds in Florida has left the species free of the dominance of ugly mutations that have ruined many other good aquarium fish. Typical J. floridae of today probably look identical to the specimens so eagerly greeted in Europe over 70 years ago. Unfortunately, that appearance gets masked in the living conditions of many fish shops, and poor understanding of the needs of this fish often has turned a real swan into an ugly duckling.

As in most killifish, the male and female are different in appearance, but their coloring is as variable as any chameleon. Each has a different kind of attractiveness, but both may be quite dull and drab in the wrong conditions. Their behavior is as interesting as their appearance. In this paper, the author proposes a hypothesis to answer the question of why there are so many conflicting descriptions of this species. The breeding behavior under two different environments, and their general behavior is described, following the description of the fish and proper living conditions. A concluding section puts forth the hypothesis. A proposal for defining correct conditions for keeping and breeding Jordanella floridae is advanced.


The body is much shorter and more laterally compressed than most other cyprinodonts. The unique spiny fin rays and unusual body qualify it for a separate genus. The body of both sexes is similar, with the male size about 25-30% larger than the female (3˜ vs. 2 ¼˜). The flattened sunfish-like shape, with dorsal and anal fins displaced to the rear, gives it an unmistakable silhouette. It is easily the most colorful of our native aquarium fishes, rivaling the dwarf gourami in overall attractiveness. The origin, unique shape, and bright colors should qualify the Jordanella floridae as the signature fish in the AKA logo, rather than some non-native that is rarely kept by most modern killifish aquarists. The particular color pattern of the male is even more reason we should proudly display this fish as our logo.

In a well lit, heavily planted tank, the male takes on the appearance that leads to the common name. "American-Flag Fish" requires the hyphen of a compound adjective, for the male looks as if he dressed in the national pennant. [Almost all other authors and editors seem to miss this simple grammatical point] With red stripes on the sides, and an upper fore-quadrant of deep blue, the resemblance is uncanny. The iridescent green-white spot on each scale makes the stars in the blue field, as well as the "white" rows between the red stripes (if you don’t mind a grass-stained look to the white). The upper and lower edges of the scales are bright red, forming solid, horizontal, brilliant red stripes. The transparent unpaired fins are a pale sky blue, but dorsal and anal are so covered with red markings that red is the dominant hue.

The female sports a false eyespot in the center of her side, directly below the start of her dorsal fin, and another in the rear base of her dorsal fin. Her basic color is tan to gray, and only the central portion of two or three scale rows may carry the iridescent green shine. She has a chameleon-like ability to shift colors and patterns in all kinds of interesting ways. Sometimes a checkerboard, then vertically barred, her most happy appearance is to echo the central eye spot several times back toward the caudal fin, each spot with less contrast as the tail is approached. At the height of breeding passion, she can become a buttery bright yellow, with almost no dark body markings.

The eyespot on the side of the male is still present, exactly at the right angled corner of the blue star field. It is not so hard-edged and well defined as in the female. While the male loses his dorsal spot as he matures, the female’s jet-black dorsal spot has a brilliant white "iris," making it more obvious than her normal eye. It should confuse many predators.

The male flashes his bright red unpaired fins, to attract the female’s attention, and uses them in the actual mating as described below. The upward facing mouth has somewhat wide fat "lips." His sharp teeth are capable of taking neat bites out of sword plant leaves, if enough algae, riccia and duck-weed aren’t present to satisfy the craving for vegetable matter. Their face has an expression that some have described as "froggy."


Like many partially vegetarian fish, the routine behavior is a slow and dignified search for algae, and a calm resting position among top weeds. In shallower tanks, the resting position may be nearer the bases of plants. A mated pair will spend most of their non-breeding time in close proximity, with lots of affectionate brushing and touching. Rarely will they allow the other out of visual range. While seldom molesting others, more aggressive species can cause the floridae to become timid and to hide. Like many killies, the young do become frantic when frightened, but this tends to go away with age. Small babies are often very hard to see. They instantly dive for cover at any approach to the tank.

The most striking behavior is during mating, described in detail below. The spawning behavior is radically different in different conditions, which has led to a lot of confusion in the literature. 1,3-8,10 Hopefully, this report will start to clarify this point, and future efforts can proceed with better direction. Most of the cited references contain some material factual errors, and only the JAKA/Killie Notes references should be trusted. 2,9 In particular, the males are larger than the females, they are very brightly colored, they don’t "dash around" the tank, and they don’t molest other fish, despite the claims of some famous encyclopedists.


The literature is, again, somewhat divided on desirable conditions. The J. so readily adapts to very different situations that most stated conditions are probably correct. This author has obtained viable eggs from the same pair, both in soft, too-warm, deep, acid water, and shallower, hard, cooler water. The only requirement seems to be reasonable acclimation, and adequate mix of animal and vegetable matter in the diet.

They first spawned in the top plants of a 55 gallon "Amazon" plant tank. Since the temperature was 81º F. and the hardness was down around 2 dGH, with pH about 6.2, the spawning was a complete surprise. These parameters were well outside the range of almost every reference, yet the floridae happily deposited eggs on hygrophila leaves, duck-weed roots, floating water sprite and anything else near the surface. Introduction of a power head caused enough surface turbulence that they tried spawning on lower plants and an algae-covered log. They went back to surface spawning when the current was directed slightly downward, leaving some still corners at the surface. They never attempted to spawn on the bottom.

Some days after completion of the spawning round, they were generally peaceful. However, an Apistogramma macmasteri pair started defending a new brood, and the female J. floridae simultaneously showed some tattered fins. Moving the pair quickly to an old 10 gallon tank, they received only hastily drip-acclimation to the 74º F., hard-water tank. dGH was estimated at about 20, but was not measured, at the time, and pH was well above 7 (above 7.4 without CO2 injection). The depth of the 10 (8.5˜ from gravel to surface) was much less than the tall 55G show tank (16˜). Some salt had been added earlier, but intervening partial water changes made the residual concentration uncertain.

Heavy rear-corner planting in the 10G filled all the swimming space but a central clearing by the front glass. This turned out to be an observational jackpot, for the area chosen for next spawn was within range of a strong hand-held magnifying glass, in the center of the clearing.

Even with the abrupt change in conditions, the male harassed the female, and, within a day, spawning resumed. Fussy about conditions, they are not!

Reproced with kind permission from:

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