question

It's Lent, which to the uninitiated, is the period of 40-odd days before Easter where people give up the things they like, typically meat and alcohol. We never do the whole 40 days, but usually just the last week. Talking to my friends who are sorta fasting had me wondering about something, cuz they didn't give up all types of meat - they're still okay with having seafood. So how come it's okay to have fish but not chicken? They're both still animals. Are sea creatures lesser animals? Is it less cruel to kill a fish than it is to kill a chicken?

pourquoi??