Do octopuses, squid and crabs have emotions?

Why. Would. They. Not?

Biology is not science.

Ask yourself: what causes 'emotions' in humans? Chemical/molecular balances and imbalances. Same happens in any creature you care to name. Unless you suppose that all other creatures are static unchanging automatons at the molecular level ... which is mind-blowingly stupid.

Also: what if other creatures have emotions but they are not identical to what we call 'human' emotions.

Again: biology is a farce when it tries to be 'scientific'.