Understanding Live Fish Options
Here’s a quick guide to help you choose the right option when purchasing live medaka from our shop. Sizes and sexing are carefully selected, but please note that fish may vary slightly by strain, age, and growth rate.
Juvenile (Unsexed)
Young fish, typically 1.0–2.5 cm in size. They are too early to sex and often have not fully developed their final traits yet. As such, they are not graded for color, pattern, or fin type at this stage.
Female
Confirmed female medaka, usually 2.5–3.5 cm. Selected by experienced staff, but please note that 100% accuracy cannot be guaranteed for younger fish.
Male
Confirmed male medaka, also typically 2.5–3.5 cm. Identified by fin shape and behavior, but final confirmation may develop with maturity.
Breeding Pair (1 Male + 1 Female)
One male and one female—ideal for those starting a breeding line or looking for a guaranteed pair.
Trio (2 Females + 1 Male)
One male and two females. This setup helps maximize egg production and is commonly used by breeders.
SS Grade Pair
A premium hand-selected male and female pair with top-level traits. These are our highest-grade specimens, chosen for exceptional color, form, and balance — ideal for serious breeders and collectors.
⚠️ Please note: Sexing is done to the best of our ability at the time of shipping. Juveniles cannot be sexed or graded for traits. Some strains—especially short-body types like Daruma—naturally grow smaller than standard-bodied medaka. In some cases, longfin or swallow-tail varieties may be difficult to sex accurately due to their flowing fins and slower development. If you believe there is an error in the sex of the fish you received, please don’t hesitate to reach out via our Contact Us page.
🐟 If your goal is serious breeding, we highly recommend purchasing multiple breeding pairs or at least two trios. Just like people, medaka have their own personalities and chemistry — and not all combinations will result in successful breeding. Having more than one group increases your chances of forming compatible pairs and achieving strong egg production.
