Panda Medaka (パンダメダカ)

A unique medaka with panda-like eyes

Overview

The Panda Medaka (パンダメダカ) is a captivating variety of the Japanese rice fish (Oryzias latipes), best known for its distinct black eye markings that resemble the facial features of a panda. This trait, combined with its lighter body coloration, creates an adorable and contrasting appearance that has made it a favorite among medaka enthusiasts.

Origin and Characteristics

The defining characteristic of the Panda Medaka is its striking dark eyes, which are caused by a mutation in the mpv17 gene. This genetic mutation affects iridophore development—the reflective pigment cells responsible for producing shine in the eyes and body. As a result, iridophores are absent in the eyes and parts of the body such as the belly, producing the signature panda-like appearance.

This discovery is detailed in a 2023 research article titled:
“Discovery of the Novel Iridophore Mutant Medaka ‘panda (pa)’ and Identification of the Causal Gene mpv17.”
In the study, scientists successfully isolated the mpv17 mutation and demonstrated its causal link to the panda phenotype. (Authorea, 2023)

Color Variations

Through selective breeding, breeders have developed several visually appealing subtypes of the Panda Medaka while retaining the signature dark eyes:

• White Panda (白パンダ) – White body + black eyes

• Blue Panda (青パンダ) – Light blue hue + panda eyes

• Gold Panda (黄金パンダ) – Shimmering golden body with dark eyes

• Yellow Panda (黄パンダ) – Bright yellow body + black eyes

• Brown Panda (茶パンダ) – Earth-toned body + panda eyes

These variations highlight the versatility and charm of the panda eye trait across different color morphs.

Breeding and Care

Panda Medaka are easy to keep and breed, like most medaka strains. However, to preserve the panda eye phenotype, selective breeding is essential. Pairing fish with strong panda characteristics ensures higher expression in future generations. Some offspring may display partial iridophore development or revert to standard eye pigmentation, so regular culling and selection are required to maintain quality.

Conclusion

The Panda Medaka offers more than just cuteness — it provides insight into genetic pigment expression and medaka biology. As a genetically distinct and visually unique medaka, it continues to gain popularity among both casual aquarists and medaka breeders. With a wide range of color morphs and its unmistakable eyes, the Panda Medaka remains a treasured ornamental strain within the world of Oryzias latipes.

Sources / 出典:

• T-Aquagarden – パンダメダカ
• めだかの館ブログ – 品種分類案2-16 パンダ
• Authorea – Discovery of the Novel Iridophore Mutant Medaka “panda (pa)”