I composed one sentence.
一人の人魚は「彼は動いていない,死んだでしょう」と言いました。The mermaid said 'It seems he isn't moving, maybe he is dead'
Is it right to say 一人 about mermaids? If they are not humans, should I use special counting suffix? are there any another mistakes?
1人の人魚は...言いました
The mermaid said...
-- 1人の人魚 would be more like "one mermaid" or "one of these (two or more) mermaids" rather than "the mermaid".