Humans have brain receptors for benzodiazepines, which reduce anxiety.
Similar receptors have been found in mammals, birds, reptiles, amphibians and fish. The capacity of fish to suffer 5. It depends on a number of factors - the type of fish, the experience of the tagger, that time out of water, the type of tag, the damage from capture, and so on. But, some tagging mortalities always occur, and it can be severe. The material is then pulled through so that the hook sits on the head of the baitfish.