Did you know that killifish are found in the Middle East? One species, Aphanius mento, sometimes known as the Persian killie, is from that region and has been an aquarium favorite for many years.
Aphanius mento is widespread throughout the Near East. Its range runs from around the Dead Sea and Jordan Valley in Israel up through Lebanon and Syria into south central Turkey and then down the Euphrates and Tigris river valleys into the Shat al Arab marshes near the Persian Gulf. While many species which are closely related to Aphanius mento live in marine or brackish water, Aphanius mento is only found in freshwater or lightly brackish habitats such springs, creeks, rivers, and small lakes. In nature, you will find it in shallow water, close to or in vegetation where the males establish their spawning territories.
Aphanius mento was first described by Heckel in 1843 and has been kept by aquarists for a long time. Nonetheless, it has never been readily available. After attempting to keep and breed the fish numerous times over the past 20 years, I believe that I know why.
In some regards, Aphanius mento can be an easy fish to keep. Like our desert pupfish, it has the ability to adapt to a wide range of temperatures. Recently, I moved a few outside into a large breeder flat (30"x24"x12") where they survived a northern California winter. Although this proved to be a mild winter, temperatures did drop into the low 30's from time to time. At the present, the same fish are basking in the same tank with our summer heat (highs from the mid-90's to mid-100's). There is no doubt in my mind that they would thrive in a fish pond, if I had one.
Aphanius mento is also an easy fish to feed. While they enjoy live foods, they also do well on flake foods. In fact, I'd recommend an algae flake food as a regular item in their diet.
Aphanius mento thrives in the type of water found in most communities in the United States. While most killies come from soft, acid waters, the Persian Killie prefers a hard, alkaline chemistry. If you keep African Rift Lake cichlids, Aphanius mento likes the same conditions.
Why, then, is this fish hard to find? In my experience, there are several reasons. First, Aphanius mento requires space. This is quite a contrast to the average killifish that is content in a two gallon aquarium. Enough though their maximum size is about two inches, a group of Persian killies should be kept in a 45 gallon aquarium, and even bigger is better. A breeder flat or large plastic "blanket" box can be used to breed the adults. In this "small" container, you will need to closely monitor the females. The dominant male can be extremely aggressive toward the females, and the females need room to run. Without enough space, you will end up with a lonely male.
I did not experience success keeping Aphanius mento until I started using a 22 gallon breeder flat (24"x20"x10"). You can keep about 20 young adults in this set-up. By using a "colony" approach with sufficient "elbow room," the dominant male seems to lose some of his aggressiveness and seems content to guard his spawning site. The energy required to be dominant eventually tuckers the male and, with a colony, there is always another male waiting to become the big stud. This keeps your egg production rolling and provides some genetic diversity.
Aphanius mento are generally aggressive only among themselves. They seem to get along, particularly while they are young, as long as they cannot be confused with food. The Persian Killie generally ignores other fish species, particularly when the other species are clearly different, and actually seem to do quite well when kept with other (dither) fish that are similarly sized.
The second problem I experienced was obtaining eggs. When I used floating and/or bottom mops, the egg harvest was slight or nonexistent. It was obvious that the adults were predating the eggs and I needed to find a way to reduce this. Success came when I tried some plastic "breeder grass." There are two varieties of this and the one I used was a long stringer with somewhat stiff plastic "leaves." This form is also known as "guppy grass" because it can be floated. I did not use the floats but rather bent it into a horseshoe shape and let it settle on the bottom. The dominant male took up residence in the middle of the horseshoe and chased everyone else away, unless it was a female interested in spawning. The reduced the egg predation and my harvest went up dramatically.
Hatching the eggs was no problem. I kept them in a lightly colored (from acriflavine) water in a separate container. The eggs hatch in 6 to 14 days depending upon temperature. The fry take a few days to absorb their yolk sacs. At the point when they become free swimming, you can feed them baby brine shrimp and they grow well.
A third problem that occurred was the sensitivity of the fry to water changes. While the fry need frequent, small water changes to obtain good growth, too large of a change, even with well aged water of the same temperature, would occasionally wipe out a fry tank. This sensitivity seems to be most acute at the ¼ to ½ inch size. The best advice is to use a large rearing container so that your small water changes make a limited impact on water conditions.
Some aquarists might consider the growth rate of Aphanius mento to be another problem. This is a slow growing species (compared to most killies), with about a two year lifespan. Males require about 4 to 6 months before they become sexually mature and begin to display their colors, and they will only be about ½ inch in size at this point. In a crowded environment, only the most dominant males will display their colors. The more room you provide, the more territorities there will be, and with more territories, more males will exhibit their flashy colors as they defend their turf.