The Golden Wonder is a selectively bred golden (xanthic) form of the striped panchax, a killifish from the slow streams, ponds, swamps, and rice paddies of India and Sri Lanka.
At around 10cm (4in) it is one of the largest killifish commonly kept, shaped like a miniature pike with a flattened head and an upturned mouth built for taking prey at the surface.
Unlike the famous annual killifish, it is a non-annual species that lives roughly four to five years, so it needs no seasonal drying of its eggs or other special breeding tricks to keep going.
It is hardy, adaptable, and forgiving of a wide range of water conditions, which makes it the easiest entry into killifish keeping.
Its challenges are behavioural rather than technical: it swallows small tankmates whole and it is a remarkable jumper.
Housing
Provide at least 76 litres (a 20 gallon long) for a trio, and prioritise floor space and surface area over height because these fish live almost entirely in the top few centimetres of water.
Hold the temperature at 22-25C (72-77F) with a heater, keep the pH between 6.0 and 7.5, and aim for soft to moderately hard water (about 5-19 dGH); they adapt to a wide range without fuss and even tolerate a little added salt.
A tight, gap-free lid is the single most important piece of equipment, as Golden Wonders are famous escape artists that will find the hole around a filter cable or feeding hatch.
Floating plants soften the light, give the fish cover to lurk beneath, and noticeably reduce jumping.
Keep the flow gentle and fully cycle the tank before the fish arrives.
Diet
Golden Wonders are surface-hunting micropredators that eat insects, insect larvae, and small fish in the wild.
Frozen and live foods such as bloodworms, brine shrimp, daphnia, mosquito larvae, and flightless fruit flies are taken eagerly from the surface and should form the core of the diet.
Most individuals learn to accept floating carnivore pellets and flakes, but newly bought fish often refuse dry food for the first week or two.
Food must float or sink slowly, because they rarely pick anything off the bottom.
Feed once or twice daily only what is cleared within a couple of minutes, as they will gorge given the chance.
Health
This is a robust fish, and the most common cause of death is not disease but a leap through an uncovered gap in the lid.
Make checking the lid part of every feeding and maintenance routine.
Like most aquarium fish they can develop ich, velvet, or fungal infections after chilling or shipping stress, so quarantine new arrivals for a few weeks and keep the temperature stable.
Clamped fins, refusal of live food, or hanging low in the tank are warning signs, since a healthy Golden Wonder patrols just under the waterline.
With clean water and a varied diet they commonly reach four to five years.
Temperament
Golden Wonders are peaceful with anything too large to swallow and predatory toward everything else.
Neon tetras, Endler's livebearers, dwarf shrimp, and fry all register as food, and adding one to a nano community is the classic keeper mistake.
Sensible tankmates are calm, similarly sized species that use the middle and lower water, such as corydoras, larger rasboras, and peaceful barbs.
Males are the larger, brighter, more pointed-finned sex and spar with rivals over surface territory, so keep one male with two or more females unless the tank is 100 litres (26 gallons) or more with heavy floating cover.
Expect long spells of motionless lurking beneath plants broken by sudden dashes at food; this ambush rhythm is normal behaviour, not illness.
A good fit for
First-time killifish keepers wanting a hardy, long-lived species
Single-species setups or carefully planned communities
Keepers who enjoy watching surface-hunting, ambush-predator behaviour
Covered, planted tanks with calm, similar-sized mid- and lower-water tankmates
Common mistakes to avoid
Eats any fish or shrimp that fits in its mouth
Exceptional jumper; one lid gap is usually fatal
Males spar; keep one male per standard tank
New arrivals may refuse dry food at first
Needs floating or slow-sinking food; rarely feeds from the bottom
Beginner
Beginner
Beginner
Beginner
Beginner
Beginner