Simplify the following text for a Grade 8 native English-speaking person.
Original: Freshwater eels ( unagi ) and marine eels ( conger eel , anago ) are commonly used in Japanese cuisine ; foods such as Unadon and Unajuu are popular but expensive .
Simplified: Freshwater eels ( unagi ) and marine eels ( Conger eel , anago ) are used in Japanese food .