Wide-Fin Medaka
Wide-Fin Medaka is not a single named variety but a trait name for a change in fin shape. Fish with this trait have a broad caudal peduncle (the base of the tail) and dorsal and anal fins with many soft rays that make them look long and broad. The trait was found in Kitatsuji Fin-Long. Adults are small, yet the spread fins stand out when seen from the side. Care is rated intermediate, so a gentle setup and careful choice of tank mates matter. Reliable data on lifespan is scarce, so no firm figure can be given.
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Wide-Fin Medaka key facts
- Care level
- Intermediate
- Lifespan
- Few reliable data
- Size
- About 3-4 cm (wild medaka reach up to 4 cm SL: FishBase)
- Diet
- Omnivore (floating prepared foods, live foods such as daphnia)
- Container & Tank
- Wide fins are best seen from the side in a glass tank; avoid sharp décor.
- Breeding
- Expression varies by variety and line; choose breeders with long dorsal and anal fins and a thick caudal peduncle.
- Tank Mates & Compatibility
- Peaceful and fine with other medaka of similar size. To keep the variety's traits, do not let it breed with other varieties in the same container.
- Diet & Feeding
- Give floating food that is eaten within 3-5 minutes: at least twice a day in summer, once a day in spring and autumn, and little or none outdoors in winter.
- Cautions
- Never release ornamental medaka into rivers, ponds or paddies; hybridisation causes genetic pollution of wild medaka.
About Wide-Fin Medaka
Wide-Fin Medaka is a trait name for fish with a broad tail base and long, broad dorsal and anal fins, found in Kitatsuji Fin-Long. A small medaka; intermediate level.
7 things to know before welcoming a Wide-Fin Medaka
1A Trait, Not a Variety
Wide-Fin is not a single named variety but a trait describing a change in fin shape. It was found in Kitatsuji Fin-Long, and body color and other features can differ from fish to fish and line to line. When choosing, check both the variety name and whether the fins actually show the trait.
2What to Look For
The key signs are a broad caudal peduncle (the base of the tail) and dorsal and anal fins with many soft rays that look long and broad. Photos taken from the side make the fin spread easiest to judge.
3Keep Currents Gentle
Because the fins spread wide, strong currents may make swimming harder and put strain on the fins. A gentle filter such as a sponge filter, with the outflow aimed away from the fish, is a safer choice. Pick smooth plants and decor that will not snag the fins.
4Choose Tank Mates Carefully
Fish that nip fins or chase others around can damage the fins. The safest start is to keep Wide-Fin medaka together, or with other calm medaka. If you do mix species, check the fins often.
5Watch for Fin Damage
Broad fins can be easy to damage, so look each day for shrinking, splits or cloudy whitish patches. If something looks wrong, first review water quality and how the fish get along with tank mates. When in doubt, ask someone experienced with fish health.
6Water Changes and Feeding
Their small bodies mean water quality can shift quickly, so change a little water often to keep conditions steady. Feed only what they finish and remove leftovers promptly. During water changes, avoid sudden temperature differences and strong flows that could stress the fins.
7Preparing Before Arrival
Set up the tank ahead of time and let the water settle before the fish arrive. On arrival, float the bag to match temperature, then add a little tank water at a time to acclimate them. Move them with a soft net or a cup so the fins are not damaged.
Frequently asked questions about Wide-Fin Medaka
- Q.What kind of medaka is the Wide-Fin Medaka?
- A.It is not a specific variety name but a trait name for a change in fin shape. The tail base is broad, and the dorsal and anal fins have many soft rays and look long and broad. The trait was found in Kitatsuji Fin-Long.
- Q.Can beginners keep it?
- A.Care is rated intermediate. Because you need to think about gentle currents and suitable tank mates to protect the fins, it is best to get used to basic medaka keeping first.
- Q.How big does it get?
- A.There is little data on the adult size of this variety, and individuals vary. It is a small medaka, but its spreading fins do best in a roomy container.
- Q.How long does it live?
- A.Data on the lifespan of Wide-Fin Medaka is scarce, so we cannot give a firm number of years. Steady water management and regular checks of the fins are the basics of keeping them for the long term.
- Q.Is the fin shape passed on to offspring?
- A.How much is passed on varies by line and by individual, so nothing can be promised. If you plan to breed them, ask the seller about the parent fish and their line.
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Care difficulty, lifespan, size and diet — all basics covered.
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