“Kohaku Lam Medaka Ricefish”

Kohaku Lam Medaka Ricefish (Oryzias latipes) Species Summary

General Overview:

The Kohaku Lam Medaka is a selectively bred strain of Oryzias latipes, known for its striking white body, red head markings (Kohaku pattern), and sparkling metallic sheen (Lam). Originating from Japan, these ricefish are renowned for their graceful swimming, peaceful temperament, and adaptability to a wide range of conditions. Hardy and beginner-friendly, Kohaku Lam Medaka are perfect for nano tanks, patio ponds, or aquascapes, where their coloration and shimmer can truly shine.

Scientific Classification:

Family: Adrianichthyidae

Genus: Oryzias

Species: O. latipes

Common Names: Kohaku Lam Medaka, Japanese Ricefish, Sparkle Medaka

Natural Habitat & Distribution:

Oryzias latipes is native to East Asia, including Japan, Korea, and eastern China

In the wild, they inhabit slow-moving streams, rice paddies, ditches, and ponds

This particular strain (Kohaku Lam) is captive-bred in Japan and is not found in nature

Adaptable to a variety of environments including indoor aquariums and outdoor tubs or mini ponds

Physical Characteristics:

Size: 11.5 inches (2.54 cm)

Body is pearlescent white with a bold red-orange head patch (Kohaku coloration)

The Lam trait adds a metallic shimmer, particularly noticeable under direct light

Slender body with short fins; females often have a rounder belly when carrying eggs

Easily visible from above, making them ideal for top-down viewing ponds or bowls

Behavior & Social Structure:

Peaceful, schooling fish best kept in groups of 6 or more

Active swimmers, often seen cruising mid-to-upper levels of the tank or pond

Very social with their own species; compatible with other peaceful, small fish

Do well in species-only setups or gentle community tanks

Extremely curious and interactive with their environment

Water Parameters & Aquarium Care:

Temperature: 6478F (1826C); can tolerate lower temperatures down to ~50F (10C)

pH Range: 6.58.0

Water Hardness: Soft to moderately hard (520 dGH)

Tank Size: Minimum 10 gallons for a small group; more space preferred for active swimming

Substrate & Decor:

Substrate is optional but fine gravel or sand is ideal

Decorate with plants, floating cover, and gentle flow

Thrive in well-lit tanks where their metallic scales sparkle

Filtration:

Gentle to moderate flow

Maintain stable, clean water, especially for breeding and color intensity

Diet & Feeding:

Omnivorous and easy to feed

Preferred diet includes:

High-quality micro pellets or flake food

Frozen/live foods like baby brine shrimp, daphnia, mosquito larvae

Occasional treats of vegetable matter (algae-based flakes, spirulina)

Feed 12 times daily, only what they can eat in a few minutes

Breeding & Reproduction:

Egg scatterers and very easy to breed in captivity

Females carry sticky eggs attached to their vent area before depositing them on plants or spawning mops

No parental care; eggs hatch in 710 days, depending on temperature

Fry are tiny and should be separated from adults if survival is desired

Feed fry infusoria, powdered fry food, and eventually baby brine shrimp

Interesting Facts:

The name Kohaku is inspired by Koi patternswhite base with red markings

Lam refers to the metallic glitter gene introduced through selective breeding

Medaka have been used in scientific research and were even sent into space experiments due to their resilience

Unlike many tropical fish, Medaka can be kept outdoors seasonally in temperate climates

Conservation & Sustainability:

This is a captive-bred ornamental strain, not collected from the wild

Widely bred by Japanese and international breeders

Always purchase from reputable sources to ensure quality and healthy genetics

Final Thoughts:

Oryzias latipes Kohaku Lam is a stunning, hardy, and low-maintenance ricefish, ideal for both beginners and seasoned aquarists. Whether viewed from above in a patio pond or from the side in a planted tank, their coloration and sparkling scales make them a visual highlight. With peaceful behavior, cold tolerance, and easy breeding, theyre a versatile and rewarding species that adds elegance and charm to any freshwater setup.