Do YOU think invertebrates are sentient?

According to Donald Broom ( Emeritus Professor of Animal Welfare at Cambridge University) "sentience is not confined to animals with large or human-like brains. Moral standing should be accorded to all animals, not just vertebrates: invertebrates deserve moral consideration too. Carefully defining the relevant terms can help clarify the relationship between sentience and welfare. All animals have welfare but humans accord more protection to sentient animals. Humans should be less human-centred".
Through the legal lens what would be the cost and consequences of providing invertebrates with "moral standing" as suggested by Prof. Broom?
You can read more about his published opinion at the source website