[Vicious]

Spoiler:

That's not the 8th crew member. That's Masira, he's one of the Gorilla Brothers who work for Monbran Cricket. Did you check the name of the CD? Jungle Fever. And there's a monkey there Also, this CD is kind of old. One Piece is in chapter 323 and no new member has entered the Straw Hats aside from Nico Robin.
You all will get to see him in the beginning of the Skypiea arc (in the Jaya arc, the prelude for Skypiea).

So no, this is not true. If you read the manga you would know that