'paiche' originates from Peruvian Spanish, likely from an Amazonian indigenous language (regional local name 'paiche'), where it was used to refer to the large freshwater fish.

'paiche' entered regional Spanish usage in Amazonian areas and was later adopted into English ecological and fisheries literature as 'paiche' without major change.

Initially it referred to the local name for the fish and over time has retained that specific meaning in both regional Spanish and English usage.