Sockeye salmon natural selection against large bodies. Populations with higher levels of predation tend to evolve smaller body size. Without the threat of predation, salmon that breed early in the season live longer than those that breed late in the season. Other ecological factors like stranding effect select for smaller body size in sockeye salmon when present in a habitat. Stranding is when salmon swim into dry land or shallow water during their migration for spawning and die from suffocation. In fact, studies show that the Sockeye salmon with the largest bodies are most susceptible to stranding mortality. Reproduction is marked by
Fear of fish by what is now called graduated exposure therapy: In contrast, radical exposure therapy was used successfully to cure a man with a "life affecting" fish phobia on the 2007 documentary series, "The Panic Room". Historically, the Navajo people were described as being ichthyophobic, due to their aversion to fish. However, this was later recognised as a cultural or mythic aversion to aquatic animals, and not a psychological condition. The "Journal of the American Medical Association" have published a research paper addressing the fears of eating fish because contaminants, such as mercury may be accumulated in fish. In his autobiography, Italian