Medaka Strain – Deep Sea

Discover the refined beauty of the Deep Sea medaka (Japanese name: 深海メダカ) with this premium breeding pair — 1 male and 1 female. Known in Japan as Shinkai, this strain is admired for its soft, elegant blue tone that resembles the clarity of deep ocean light rather than darkness.

The Deep Sea medaka was developed in 2010 by Japanese breeder Ryusei Nagaoka (長岡龍聖). It originated from Blue Miyuki (青幹之) lines that showed a rare internal blue peritoneum. Through years of selective breeding, external shine and black pigmentation were gradually removed to highlight this internal feature, known as fukumaku ao.

While its name evokes depth and mystery, this medaka’s refined appearance offers a tranquil yet captivating presence. It stands out beautifully in black tubs or among white-bodied medaka.

Strain Name (品種名): Shinkai (Deep Sea)
Breeder (作出者): Ryusei Nagaoka (長岡龍聖)
Released: 2010
Key Trait: Blue peritoneum (fukumaku ao)
Lineage: Derived from Blue Miyuki, selectively refined for internal blue clarity

Learn more about the Deep Sea medaka on our Medaka Encyclopedia page.

• Includes: 1 Male + 1 Female
• Condition: Imported medaka
• Creator: Ryusei Nagaoka (長岡龍聖)
• Shipping: UPS 2-Day Air strongly recommended

※ All photos shown are original images taken by SNR Medaka USA. Unauthorized use or reproduction is strictly prohibited. Photos are for reference only — actual fish may vary.

Important Purchase & Shipping Information

For customers who purchase physical Medaka:

• As a general rule, we do not accept cancellations for Medaka sold in-kind after the order has been confirmed.
• Please note that the appearance may differ depending on the lighting and the color of the breeding container.
• This item is not eligible for returns or exchanges.
• We ship to the Continental U.S. only. Sorry, we currently do not ship to Hawaii or Alaska.

Shipping Information

• Please choose UPS 2-Day Air. DOA only applies to 2-Day Air. Please read Shipping Information – SNR Medaka USA.
• Shipping may not be possible due to lack of stock, poor condition, or other issues. In such cases, we will cancel your order, and you will not be charged.
• If you purchase multiple sets of live Medaka, we may combine them into one shipment.