One of the few native American killifish to regularly find its way into pet/aquarium shops is the southern American Flagfish, Jordanella floridae.
Flagfish are considered by many to be an ideal beginner’s fish, being undemanding, peaceful, well colored, and with interesting but not necessarily difficult breeding habits.
Even when not in full breeding attire, the fish are attractive. Males show a blue-green base color with horizontal red stripes on the body and fins. Females are basically green with a black dorsal spot. Maximum size for males is about 2 inches; females are smaller.
Requirements are simple: temperature of 65-70F, water medium hard, neutral or slightly alkaline, with regular partial water changes. Some recommend brackish water, but this is not necessary. Although they are not picky eaters,they are related to pupfish (Cyprinodon) and require either plants to chew on or a high proportion of vegetable matter in the diet.
Aquarists who have bred the fish report that they can be successfully spawned as pairs or in groups,and that theyalso sometimes act as nesting fish, digging in the substrate and carefully guarding eggs and fry. As with other species of killifish, it is recommended that the breeders be conditioned separately and then brought together in the spawning tank. When the female begins to fill with eggs, increase the temperature to 78-80F. Add spawning mops and the male, and in a few days begin harvesting eggs.
Methylene blue should be avoided, since it can have an adverse effect on eggs and fry. Once eggs have hatched, add a snail to the container and begin feeding using Liquifry or similar food. Within a day or so the fry, which tend to grow slowly at first and at different rates, can take newly hatched brine shrimp.
— GCKA Newsletter, November 1997