They do not "think" or "feel" like other animals.
I am sure I don't at all know what you mean. Fish do think and feel. Additionally, they exhibit the exact same stress hormones as other animals when feeling pain and discomfort (including capture) and it has been measured time and again in scientific studies. They make the same daily choices that other animals make about their own survival including prey and predator interactions, social dominance hierarchies, avoidance of pain or death, foraging/hunting for food. Thinking fish are stupid is just something that people choose to do because they want to justify eating fish. Some further reading from recent scientific journals for those who are open to it:

Catch and release fish learn to avoid the hooks of anglers:
Askey et al (2006) Linking angling catch rates and fish learning under catch-and-release regulations, North American Journal of Fisheries Management 26(4) 1020-1029

Sub-ordinate fish in social groups steal food from dominant fish by using previous learning, expectancy of reward, and behavioural and learning plasticity
Hollis et al. (2004) Novel strategies of subordinate fish competing for food: learning when to fold, Animal Behaviour 68(5) 1155-1164

Fish are found to feel stress, pain and fear and their welfare should be considered especially for aquafarming application
Chandaroo et al. (2004) Can fish suffer?: perspectives on sentience, pain, fear and stress, Applied Animal Behaviour Science 86(3-4) 225-250