Of the nearly 1270 known species of killifish throughout the world, many are gorgeous, but this one is a show stopper.
Known by many names, the Golden Wonder Killifish, Striped Panchax Killifish, Malabar Killifish, Piku, or simply the striped panchax (Aplocheilus lineatus) is a species of killifish, that is highly sought after by collectors for its brilliant colors.
These colors coupled with easy maintenance make this stellar, affordable fish easy to care for and a true wonder to behold.
So what should I expect from my newfound guest and centerpiece? While they might not fight crime, they can prove to be superheroes in their own right.
Species Overview
The Golden Wonder Killifish is a medium-sized, ray-finned, freshwater fish belonging to the order Cyprinodontiformes.
Although typically found in shallow seasonal ponds and slow to turbid rivers and streams on the Indian subcontinent (India and Sri Lanka) they have also been found throughout the region surviving in less than optimal pool conditions.
Through miraculous evolutionary tenacity many killifish, like the Golden Wonder have developed the ability to survive with very few resources in these challenging environments.
More often though, they find themselves at home in the flooded rice terraces of the region. Farmers not only benefit from their effective pest control (and quelling malaria mosquitoes) but also enjoy their intrinsic natural beauty.
| Category | Rating |
| Life Span | 2-4 years |
| Family | Cyprinodontiformes |
| Color Variety | Brilliant metallic colors: bronze, gold, silver with green, blue, orange or yellow mottle, spots and stripes. |
| Care Level | Beginner |
| Compatability | Peaceful with Most Types of Fish |
| Food and Diet | Carnivore |
| Temperament | Peaceful |
| Tank Size (Min.) | 20 Gallons |
| Tank Setup | Dim lighting, minimal decor |
| Size | 2-4 inches |
Rather than any killer instinct, the name of these wonder-fish derives from the Dutch word kil, meaning a small stream where these fish (killifish in general) were traditionally found by Europeans.
The name was also later adapted to this South-East Asian variant during the mass rush to reconcile the new binomial classifications with their more local, common names.
They are social fish and cohabitate easily with most other non-predators of a similar size. Compared to other commonly kept killifish, the Golden Wonder Killifish is one of the longest-lived, most docile, and easily maintained members of the genus.
Unsurprisingly this makes them one of the most popular killifish for breeders, hobbyists, and amateur aquarists alike. So, what is this masked crusader like and where do they change into spandex?
Lifespan
Depending on the habitat, their average lifespan in nature is only a few years. Some specimens have been observed over as many as 5 years, but this is seen as the exception rather than commonplace.
Killifish in general are tied to seasonal changes; with their own internal clocks tied directly to the changing wet-dry seasons prevalent in the Indian subcontinent.
In captivity, even with the utmost care, this can be difficult to replicate in a home aquarium but necessary for both breeding and promoting longevity.
The most common strategy for increased longevity involves regulating their food and simulating seasonal changes in the aquarium microcosm.
Getting your fish from a reputable breeder will ensure that your killifish are of the highest pedigree, are brilliantly colored, and live as long as possible with your optimal care.
Appearance
Most killifish can be described as medium-sized, highly hydrodynamic, vividly-colored fish. The Golden Wonder Killifish are among the most brilliant and colorful.
They tend to have brilliant metallic colors: bronze, gold, silver often with green, blue, orange, or yellow mottling, spots, and stripes.
The males are generally more colorful and larger as they need to advertise and demonstrate their reproductive prowess and genetic strengths to potential mates.
This vibrancy only increases with hormonal changes and is particularly acute when it is time to impress a potential mate.
Size
Fully mature males under optimum natural conditions in the wild can grow up to 5 inches long. The median is about 2-4 in both natural and simulated environments. Most are only a few inches long but even this can show variations by individual micro-environment.
It is also important to factor in this size relative to any other members of your community tank. Killifish are carnivorous and if it fits into their mouth, neighbors can quickly become a nice light snack.
Most other killifish live for shorter durations and mature to a small size; so always be wary when mixing and matching prospective neighbors.
Golden Wonder Killifish Care
Some aquarists believe that killifish are difficult to keep. Yes, their preference to hunt live food and nest in vanishing pools can make them seem labor-intensive.
Of all the killies that one might possibly choose, the Golden Wonder Killifish is among the easiest to keep.
Once established they will explore, hunt, territorialize their new home. The trick is always simulating their natural environment to the best of our abilities.
Tank Size
Golden Wonder Killifish love the company of others and can often be found schooling with others and sometimes isolating themselves with their own kind.
Given their modest size but a propensity to gather in often shrinking waters they are more tolerant to crowding than others.
Still make sure to give them plenty of space, a good 20 gallons base (plus 10 gallons for each additional Golden Wonder Killifish) will suffice.
They will want to hunt up and down the vertical column each day exploring their entire pool. Please give them enough space to do so without engaging in territorial spats.
Water Parameters
Normally Golden Wonder Killifish make their homes in a wide variety of slow-moving streams, rivers, estuaries, swamps, waterholes, and rice paddies of the Indian subcontinent.
While they are highly adaptable and tolerant of extremes as with many domesticated pets, you are trying your best to mimic their ideal, natural habitat.
Unlike some of its killifish counterparts, the Golden Wonder Killifish actually prefers interchanging water conditions but can also tolerate stagnating pools.
Be certain to use a simple filtration system that refreshes the water but does not produce a noticeable current.
Although Golden Wonder Killifish are generally resilient to a wide range of water pH balances, temperatures, and degrees of salinity; you always want to aim for optimum conditions. A tank near 75-80F, with neutral to slightly acidic (pH 6.8), salt-free water to make these river fish feel at home.
If you are housing other killifish alongside your showcase Golden Wonder you may want to adjust the temperature downward closer to 72-75F to accommodate their colder-climate cousins.
This compromise is just an attempt at simulating natural patterns of monsoon and dry-season, temperature conditions between their slightly varied, preferred habitats.
What To Put In Their Tank?
Again we are trying to mimic the ideal conditions of their natural habitats. Since they like slow or non-moving water, there is no need to mimic a current.
Golden Wonder Killifish also spend most of their day below the surface of shallow pools away from predators. You can stick with natural materials for your substrate and aim for minimal decor with a few good hiding spots in this simulated home and nesting environment.
This will ensure that there are defined boundaries allowing females and immature males to pass through or hide temporarily during their transit of defined male territories.
This normal territoriality becomes most acute during periods of breeding. Ensuring a good ratio of males to females (1:2 or greater) not only ensures the survival of your Golden Wonder Killifish but also helps to ensure good genetic diversity.
For foliage, consider what they would find in their natural environment. They frequently live in the rice paddies among the shade of lotus leaves.
To simulate this environment you might include dwarf lettuces and lilies like Nymphaea stellata to provide the fish with shade and hunting grounds for food.
Once your visitors have arrived, also be certain to affix a good lid to your tank. Golden Wonder Killifish are prolific jumpers and liable to escape if given the chance.
In nature, this would help them escape vanishing ponds for better ones nearby. Be sure that your lid is always securely fashioned to prevent a great escape.
Common Diseases
Like similar small freshwater species, Golden Wonder Killifish have excellent immune systems and do not suffer from many endemic illnesses. The most problematic illnesses they suffer come from fungal and viral sources.
The most common attacker is oodiniosis or marine velvet disease. It is caused by the dinoflagellate Amyloodinium ocellatum which parasitizes the killifish.
While these are omnipresent in their natural environment and usually fought off through immune response, the number of parasites in a tank can be concentrated sufficiently that weaker animals may succumb to illness.
While having a good diet and a clean, healthy tank are your best bets for prevention, if they do get sick, most health issues, like oodiniosis can be controlled through prudent quarantine of sick animals and timely use of therapeutic medications.
A word of caution: copper solutions are often used as a treatment for oodiniosis. It is a heavy metal and toxin that should be used sparingly and according to manufacturer and vet instructions. Too much copper will kill everything in the tank, so please be judicious.
Like humans, fish can easily get sick under stressful conditions or if their immune system is compromised. Illness prevention, regular tank (habitat) maintenance, regular feeding, and being respectful of their instinctual behaviors towards tank mates will make for a satisfied superhero.
What Do Golden Wonder Killifish Eat?
While their general care and upkeep are flexible and they are fairly forgiving with their dining choices certain care will maximize their health and vibrancy.
They are natural hunters preferring to take down and enjoy live foods whenever possible, only resorting to carrion or vegetal grazing in times of short food supply. In the aquarium, this equates to regular live feeding of aquatic worms and crustaceans supplemented by flake food.
A few members of the order have adapted to more omnivorous diets again demonstrating their amazing, swift adaptations at survival. Others have found niches like eating mosquitoes in malarial swamps.
A correlation has even been made in these areas where the prevalence of malaria (transmitted by mosquitoes) is directly proportionate to the number of Golden Wonder Killifish living in these pools.
Unlike most other killifish, the Golden Wonder Killifish is less finicky than its cousins who insist on live food. They’ll accept pre-formulated pellets and formulated flake food without hesitation.
Natural, unprocessed live insects and arthropods will always be preferable, but not always necessary in a pinch.
Behavior & Temperament
Golden Wonder Killifish don’t mix well with small fish and they will see very small neighbors as a possible food source. Even if not deliberate, many small tank mates have mistakenly stepped into the gaping mouth of our wonder-fish friend.
Overall they are hardy and non-aggressive, but like many fish can become stressed in the absence of food or mates.
Most of their time they cluster leisurely below the surface in small ad-hoc groups. During periods of mating, the males become more colorful and territorial in nature, although less so than many of their killi counterparts.
Golden Wonder Killifish Tank Mates
Temperamentally, Golden Wonder Killifish are fine to be with most community aquarium fish. However, given their specific dietary and climatic needs, it may somewhat limit who will also want to share their home.
Beginners hobbyists should consider keeping a species-specific Golden Wonder Killifish tank until you’ve sufficiently researched potential tank mates who like living in similar conditions.
The most commonly kept Golden Wonder Killifish companions are:
- danios
- dwarf cichlids (New World)
- freshwater shrimp (large, mature ones as smaller ones will surely be eaten)
- freshwater snails
- neon tetras
- rasboras
- swordtails
Be sure to also consider adding bottom-feeders like corydoras, loaches, and plecos as companions. These will not be competing for the same food sources, can clean up the carnivorous mess left behind by your Golden Wonder Killifish, and still thrive in their modestly low oxygen environment.
One final reminder, always be wary of the size differential between tankmates. An adult Golden Wonder Killifish who outsizes his roommates may swallow them inadvertently or see them as potential prey. This can also be said of smaller crustaceans that may be predated upon like food.
Breeding
If your male Golden Wonder Killifish goes from handsome one week to an absolute knockout the next, be wary: his hormonal balance has changed and he is ready to breed.
At this point, it is best to separate a female and her potential mate from the rest of the tank to lay their eggs. Too many others will see the eggs or juveniles as a food source and they require some extra nurturing to hatch into fry.
Like all other cases in keeping wild animals, we do our best to simulate their natural environment and optimum breeding conditions.
Normally Golden Wonder Killifish lay eggs in sandy, calm shallows; so if you can replicate those conditions in your holding tank, it will prove a fruitful breeding ground. Once the eggs are fertilized and safely tucked away remove both parents from the holding tank; now comes the only tricky part.
The fertilized eggs must be kept in the warm, moist, sand they were laid in. Make sure the nursery is a little warmer than the main tank, closer to 80C. Within 2-3 weeks (2-3 months for similar killifish) the hundred or so eggs will hatch and develop into fry.
While the fry are small they will survive by eating their egg sacs. Later on, as they develop into fingerlings they will be able to eat larger and hunt down more complex items.
Fingerlings will prove adept at taking down small aquatic arthropods and love newly hatched brine shrimp.
At this point gradually triage the tribe to remove larger juveniles to improve your overall survival rate among the children. The largest ones will be big enough to compete against others, feed themselves, and re-join the greater community. The smaller ones will always be a target for aspiring cannibals.
Final Thoughts
Few fish of this caliber come at this price point with similar ease of care. If you create an optimum habitat your Golden Wonder Killifish and their mates in the community will flourish.
By watching their behavior, observing their mating patterns, and the continuing evolution of the community you will gradually gain competency in rearing more complex species.
These beautiful, adaptable fish will not only add beauty to your own home but also be something highly entertaining to watch that isn’t glittering away on the omnipresent video screens of the 21st century.
The behaviors, attitudes, and highly-evolved hunting skills will easily amuse even the most hardened of skeptics.
Your Golden Wonder Killifish will easily outshine any 15-second video clip or human quirk. Just watch them explore, hunt, mate, feed, and compete for a few moments and it will convert even the most plugged-in of viewers to the wonderful world of the Golden Wonder Killifish.
