Yes, but she was saying that technically the number of tentacles are six, but that's only because of budget limitations, most promotion artwork feature eight tentacles. And since tentacles are technically arms, you can include her human ones to fill the number. I know Musker has described that they went through several animals, but it was when they were looking at footage of an octopus that he decided that felt right for Ursula, because they moved so sinuously across the ocean floor. And that's why they used footage of the animal as reference for Ursula's movements.
Honestly, her character itself also thematically fits octopus, because squid travel more in schools, whereas octopi stay along the ocean floor among debris, hide in caves, and work alone. They are weak animals and wait for the proper moment to attack, which suits Ursula as well who bides her time to strike at Triton. (The funny thing is that what octopi most often eat are crustaceans, which makes Sebastian's extreme fear of Ursula more personal.
) I think the only argument for squid at all is that she only has six in the movie... But even on that point, we know that they intended eight, and had to cut them down for financial reasons. Besides, squid have ten tentacles anyway, not six... Their anatomy is also different than what Ursula is shown with; aside from being more thin and long, they have some kind of hook-like features at the end of their tentacles that octopi don't have. Although in fairness, I suppose
some of the appeal of calling her squid by some people could come from the fact that she turns into a giant at the end, which may remind some of giant squid, Cthulu, the Kraken, or whatever. Still, she doesn't look like a squid and her lower portion is never referred to in that way.
I don't think there is a debate really. She is half octopus in the original film and has always been described that way these past thirty years. Then again, Ariel's not even red-haired anymore. Just make Ursula a swordfish and F&J lobsters at this point, since nothing really matters.
