The striped panchax killifish (Aplocheilus lineatus) or golden wonder killifish is a tropical freshwater aquarium fish that belongs to the genus Aplocheilus. Wild striped panchax killifish has a rather unpretentious coloring – bronze-colored body, reddish fins, and some dark vertical stripes near its tail. However, due to breeders’ efforts, a golden-colored variation of the fish was obtained – golden striped panchax. It is considered the most popular nowadays.
Habitat in the wild
The killifish habitat includes the territory of East India, and it was introduced in Sri Lanka, where they use it to control the mosquitoes population. Locals use the fish to fight mosquitoes by putting it in small freshwater ponds near their houses. Natural biotopes of this fish are slowly flowing waters, bogs, flooded lowlands, irrigation channels. It dwells in waters with a temperature of about +22…+25 °C.
The fish appeared in home aquariums more than 100 years ago (in 1909), in Germany, where it was first successfully bred. This kind demonstrated itself to be an enduring tank fish, capable of adapting quickly to various tank conditions. Moreover, striped panchax is easy to breed.
In the wild striped panchax male is about 4-5 inches (10-12 cm) long, while females are a bit shorter.
It has gray with a greenish tint body which is darker on top with black vertical stripes on it (from 4 to 6), and this is how the fish name originated — «lineatus.»
The fins have the same color as the body but are a bit paler. Anal and tail fins have black edges of different color intensities. Abdominal fins are elongated, and several of their rays transform into thin filaments.
Provided with lateral illumination, the fish looks really appealing. Scales of the adult males in the reflected light shines with bright green. For this reason, the source of light in a tank should be located closer to the viewing glass.
The tall and long anal fin, together with the dorsal and tail ones, makes a single powerful blade that enables the fish to push effectively to jump out of the water when hunting flying insects and also to change its direction under the water abruptly.
Currently, there are three color variations of striped panchax killifish known: natural, golden, and red one.
In 1993, among the fish brought to Europe from Goa province together with naturally colored species, some golden-colored species were found. The new color variation attracted the aquarists’ attention right away.
If compared to natural golden striped panchax coloring, these species were brighter, which was a rare thing among tank fishes. Their main body color was golden-yellow with unpaired fins of the same color.
The very first fish spawning showed that this attribute is inheritable. This is how the golden variation appeared in home aquariums.
In the case of the red color variation of the fish, the male body has greenish and olive-brown colors with a reddish tint. On the sides, it has small golden-green shiny scattered spots that are red on its chest. Each scale has a large red spot, due to which there is an impression that the fish body is sparkling.
Tank conditions for the successful keeping of gold and red color variations of the fish are the same as its natural form requirements.
Difficulties in keeping
Bright coloring, rather peaceful temper, and active behavior in a tank make wonder killifish desired in house ponds. Easy breeding and keeping conditions let us recommend them even for beginners to keep.
Care and keeping in a tank
Wonder killifish lifespan in a tank is about 5 years on average. They are rather resistant to any type of illness. Sometimes they don’t get it for 5 years or more.
It is better to keep striped panchax in small groups of 4 species at least. Recommended tank volume is 80 liters. At that, it must be covered since the fish can easily jump out of it.
They feel quite good at a rather wide variety of temperatures, from 20 to 30 °C. However, 24°С can be considered optimal water temperature for them. Water parameters aren’t that important for the fish, and it can dwell both in soft and hard water, preferably neutral or slightly acidic.
Optimal tank conditions are the following: moderately had water (8-15 dGH) with pH 6.0-7.5. slight deviations from optimal values don’t affect the fish significantly.
Tank setup: decorations and plants
Panchax killifish prefer staying under fluctuants. At this, the fish mouth is on the boundary of two mediums (water and air) and maximally close to potential prey, which is near the water surface.
When keeping it in a species tank or with calm tempered fishes of similar size, it often swims in the middle and sometimes bottom water layers. It likes spending time among thickly growing plants or gathering in a school under a large plant leave. In general, the fish isn’t timid, but in case of danger, they tend to hide in tank plants or under fluctuant. They turn in the direction of the threading object watching it.
In a tank, a dark-colored substrate is preferable. There should be some sickly planted areas with snags in them.
The tank lighting shouldn’t be too bright since striped panchax prefers dim light. To create such conditions, put some fluctuant on the water surface (for example, water lettuce) or use tank plants that grow their leaves to reach the water surface (Vallisneria).
Filter and heater are a must in the tank. The filter will keep the water clean, while the heater will heat the water to a comfortable temperature for the fish.
Wild striped panchax is a predator that waits for its prey under plant leaves to catch it in one move once it gets close. In the wild, its diet mainly consists of flying insects, their larvae, fish juveniles, and small fishes that swim in upper water layers.
In a tank, they aren’t demanding as for the food. They eat standard types of live, frozen, and artificial food. Its amounts must be precisely calculated since the fish tends to overfeed. As for additives, these can be blood worms, flies, and other insects.
Striped panchax killifish is a predator, but it doesn’t mean you can’t keep it with other fishes. The most important thing you should consider when selecting its tank mates is that they shouldn’t be smaller than panchax killifish. Otherwise, sooner or later, they’ll become its prey.
For this reason, keeping it with cardinal tetra, celestial pearl danio, cherry barb, dwarf pencilfish, endler guppy, fancy guppy, and similar fishes is strictly not recommended. This fish treats its small-sized tank mates as potential prey, but they try to eat them only if very hungry. The rest of the time, it doesn’t pay much attention to them. However, considering its large mouth and ability to attack abruptly, the chance of a successful attempt to eat its tank mate is very high.
The way how striped panchax killifish chases small fishes has a lot of in common with how northern pike hunts: striped panchax freezes hiding under plants and waits for its prey to come as close as it can catch it in one move. When the potential prey becomes reachable, the fish curls its tail and then straightens it and attacks the prey.
Large tank mates such as barbs (tiger barb, Odessa barb, denison barb, gold barb), large platy, swordtails, and mollies will be a good company for the fish. However, when putting very active fish together with striped panchax, ensure that the latter gets enough food.
Intraspecific conflicts are seldom the case, but you should keep the fish in groups with females prevailing there. Fights that occur between the males from time to time are more likely aimed to compete; thus, they won’t cause any serious injuries.
The fight between the males goes as follows: the rivals stay parallel to each other so that one fish’s head is against the other fish’s tail. Then they stretch their fins and stick out their gill covers, and their bodies start waving. The rival less successful during this exercise admits his defeat and leaves the duel place. The winner usually doesn’t haunt the defeated.
Gender differences: male vs. female
Females have less appealing coloring than males. The main color of their body is gray, with some sparkling golden-bronze scales on the sides. Females have shorter yellow-white fins. Their unpaired fins are more rounded with yellow-orange edges.
In the wild such coloring allows the fish to hide and makes them almost invisible among vertical stalks and water greenery. In case of a stressful situation, a rather wide dark stripe appears along the fish body. It is especially visible on the young species body.
Breeding of all color morphs is not challenging. Provided with favorable conditions and bottom substrate, they often lay eggs in a community tank. To grow the juveniles, you should remove the substrate with eggs to the incubation tank.
You can use a spawning tank of about 20-30 liters capacity with a water level in it about 1-0-15 cm high. Water parameters required for breeding are the same as when keeping the fish. There should be some fluctuant on the water surface. Small-leaved plants are used as a spawning substrate, or a bunch of synthetic filaments will do as well. To stimulate the spawning process, add some soft water and raise its temperature.
The spawning occurs inside the thickly planted tank plants. Every day the female lays several eggs on them, and you should remove them to the incubator right away. A large female can lay up to 25 eggs a day. On average, you can get about 100 eggs in a week from one female.
The spawning continues for several weeks, then a break (10-14 days). The eggs are transparent, 1,4-1,6 mm in diameter.
Incubation time lasts for about two weeks. The breeders tend to eat their juveniles. The latter are quite large and can start to feed on brine shrimp nauplii from the very beginning.
Provided with a nutritious diet and regular water renew, the juveniles grow quickly. At the age of one month, they can be 1.5 cm long. Approximately at this age, it becomes possible to define the fish sex. The male fins become sharpened elongated, and get their coloring. Aplocheilus lineatus obtain their full coloring when they become reproductive and grow 6-7 cm long. This usually happens when they are 6 months old.