Definition: The term "Yamagata" refers to a type of fish called carp, which lives in waters near Japan's main island of Honshu. Definition: The Yamagata species of carp (Ailurus fulgens) is known for its distinctive bright yellowish-green color, small size, and rapid growth rate. It is an important part of the aquatic ecosystem on the islands of Honshu and Kyushu, and plays a key role in many fisheries and aquaculture operations. Yamagata carp is typically found in water bodies such as rivers, lakes, and ponds near the main island of Japan. They are known for their rapid growth rates and can reach an adult size of approximately 2-3 inches (5-6 cm) when fully grown.