the fish below the top one is poisonous. It is dorso ventrally flat. It has dangerious stings, once my friend hooked this and he was getting out the hook and this fish sting him he was crying like anything with pain and was hospitalized immidiately. He took whole day to recover.

Yup, they do have poison spike on the side as well. Flathead fish have two short spikes on either side of their heads and on top of their heads that contain venom. The venom, while not fatal, can cause pain and infection. Some anglers believe the pain of the sting of the flathead fish can be reduced by rubbing the slime of the belly of the same fish that caused the sting on the inflicted wound, due to a particular gland in its belly. Many species are found in the Indo-Pacific, especially most parts of Australia where they are popular sport and table fish. They inhabit estuaries and the open ocean. And they're quite tasty too.