orangutang(猩猩)gorilla(大猩猩)chimpanzee(黑猩猩)
As for me, it's not a question about language but a biological problrm. Most Chinese call this three kinds of animals both as 猩猩or 大猩猩for convinet. We don't consider their differences seriously in our daily life. (*^__^*) I have to admit that people like me lack of the knowledge about animals.