Tarumi Longfin Medaka

Tarumi Longfin Medaka key facts

Care level

Intermediate

Lifespan

2-3 years

Size

Up to about 4cm SL

Temperature

18〜28℃

Diet

Prepared medaka food, green water

Lighting

The net-like sheen appears on the back and suits viewing from above, while the white, feathery fins read best from the side at an angle. Outdoors, summer sun raises water temperature sharply, so shade half the container with something such as a reed screen.

Diet & Nutrition

Commercial prepared medaka food is the staple, given in an amount finished within a few minutes. Leftovers decay and foul the water, so adjust the quantity. Green water rich in phytoplankton suits fry rearing.

Water Temperature & Quality

Slightly acidic to slightly alkaline water is considered ideal, and the water drifts toward acidic as keeping continues. Around one water change per week is the guideline, and because sudden shifts in temperature or pH cause stress, acclimatise new fish by floating the bag. FishBase records the wild water chemistry of this species as pH 7.0-8.0 and hardness 9-19 dH.

Tank Mates & Compatibility

Elongated fins are easily damaged by obstructions or crowding, so keep the container uncluttered and the stocking light. A peaceful schooling fish, normally kept as a group of the same variety. One litre of water per fish is the guideline against overcrowding; overstocking causes poor growth, reduced breeding, oxygen shortage and water fouling.

Breeding

The Medaka Web Encyclopedia states that crossing this line with morpho to make Marriage Longfin both strengthened the fusahire expression and raised its heritability. Outdoors the spawning season runs from about April to October, once water reaches 18C or above with 12-13 hours of daylight. For year-round indoor breeding, 25-28C water and over 13 hours of lighting are the guideline. Eggs hatch at a cumulative 250 degree-days, about 10 days at 25C.

Health & Notes

The Medaka Web Encyclopedia describes Marriage Longfin, bred from this line, as a fish whose finish depends on its environment. Generous stocking room and a steady water temperature are the guideline for drawing out the fusahire expression. The extended, branching fins damage easily, so keep the container uncluttered. Outdoors the fish become inactive and overwinter near the bottom as water cools, resuming activity in spring once daytime water exceeds 10C. A 0.3-0.5% salt bath is used for ailing fish, with water raised to no more than about 28C.

About Tarumi Longfin Medaka

Tarumi Longfin Medaka features a net-like body luster and long, fluffy white dorsal and anal fins. Established in 2019, it's the founding strain of the fusa-hire lineage, suited to intermediate keepers.

7 things to know before welcoming a Tarumi Longfin Medaka

1. 1Branching Fluffy Fins

   The dorsal and anal fin rays don't just grow longer — they branch and fan out into soft, white, fluffy tufts, which is this strain's signature trait. As the founding line of the fusa-hire lineage, it shows a more delicate fin texture than typical longfin medaka, fluttering gracefully as it swims. Because the fins are so delicate, keep sharp decorations and rough edges out of the tank.

2. 2Net-Like Body Luster

   A net-like sheen (an "extrabody" scale luster) spreads across the body, giving this strain its elegant shimmer. How it catches the light shifts with the angle, making it rewarding to simply watch. Each fish shows its own individual pattern in how the netting develops.

3. 3Best Suited to Intermediate Keepers

   The Tarumi Longfin is generally considered suited to intermediate keepers who already have some experience managing water quality. Because its fins are especially long, extra attention to water flow and conditions helps keep it healthy. First-time medaka keepers may want to build experience with a standard strain before taking this one on.

4. 4Grows to About 4cm

   Adults reach a maximum standard length of about 4cm. With its fins included, the overall impression is a bit larger, giving it a noticeably graceful presence as it swims. Make sure its tank or outdoor container gives it enough open space to move freely.

5. 5Protecting the Fins

   The elongated fin rays are delicate and can tear easily, so sharp decorations or coarse nets are best avoided in the tank. Use a soft, fine-mesh net when scooping it out to minimize stress on the fins. If keeping it with other fish, choose calm tankmates that won't nip at its long fins.

6. 6Stable Water Conditions

   Like other medaka strains, sudden shifts in temperature or water quality can be stressful. Regular water changes and a spot away from direct sun or temperature swings help keep it in good condition. If you use a filter, pick one with gentle flow to avoid putting strain on the long fins.

7. 7Know Its Origin

   The Tarumi Longfin was established in 2019 by breeder Seiji Tarumi as the founding strain of the fusa-hire lineage. Knowing this background adds depth to appreciating the strain's characteristics. It's also interesting to compare it with other fusa-hire strains that descended from this line.

Frequently asked questions about Tarumi Longfin Medaka

Q.Is the Tarumi Longfin suitable for beginners?

A.It's generally considered suited to intermediate keepers, so it's best to gain some medaka-keeping experience first. A handle on basic water quality and temperature management makes it easier to keep successfully.

Q.How is it different from a standard medaka?

A.Its biggest difference is that the dorsal and anal fin rays grow long and branch into soft, white, fluffy tufts. It also has an elegant net-like body luster, and it's the founding strain of the fusa-hire lineage.

Q.How large does it grow?

A.It reaches a maximum standard length of about 4cm. Including its fins, it looks noticeably larger and more striking.

Q.How can I keep its fins from getting damaged?

A.Avoid sharp decorations and coarse nets, and use a soft, fine-mesh net when scooping it out. If keeping it with other fish, choose calm tankmates that won't nip at its fins.

Q.When was this strain first developed?

A.It was established in 2019 by breeder Seiji Tarumi. It's the historic founding strain of the fusa-hire lineage.

Useful tools for Tarumi Longfin Medaka care

Learn more about Tarumi Longfin Medaka in the encyclopedia

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