红丽丽鱼 hóng lì lì yú

红丽丽鱼是属于斗鱼科的一种鱼类，又名核桃鱼。喜食薄片、冷冻的食物，如水蚤、红虫、丰年虾和蚊子幼虫。体长4~5厘米。体色素淡，但到繁殖发情时，雄鱼显现婚姻色，体红铜色，下颚至胸鳍为蓝色，非漂亮。

百度翻译提供：

Red Lili fish is a kind of fish belonging to the betta family, also known as walnut fish. Like to eat thin, frozen food, such as Daphnia, red worm, shrimp and mosquito larvae. The body length is 4~5 cm. The body pigment is light, but when it comes to reproductive estrus, the male fish shows marriage color, red copper color, and blue from the lower jaw to the pectoral fin, which is not beautiful.