Reeves' shad; Chinese shad
A species of shad (Tenualosa reevesii) found in East Asian waters. The name is typically written in katakana as ジギョ.
The Reeves' shad is a fish eaten in China and Southeast Asia.
The origin is uncertain; the kanji 鰣魚 are Chinese characters for this fish, but the Japanese reading じぎょ may be derived from Chinese or a Japanese approximation.