Sockeye salmon are red, which is the usual color of females. Even small changes in wavelength, saturation, and brightness can affect preference. Both sexually naïve males and experienced males showed the same preferences, which illustrates that preference for a red hue may be innate. Some traits that lead to reproductive success, such as body size and sexual dimorphism can affect one’s survival. This leads to opposing pressures of natural selection and sexual selection. Larger males are favored, unless the risk of predation is very high. Sockeye salmon that die prematurely from predation are typically the larger ones in a population. This shows
Fish market Fish market A fish market is a marketplace for selling fish products. It can be dedicated to wholesale trade between fishermen and fish merchants, or to the sale of seafood to individual consumers, or to both. Retail fish markets, a type of wet market, often sell street food as well. Fish markets range in size from small fish stalls, such as the one in the photo at the right, to the great Tsukiji fish market in Tokyo, turning over about 660,000 tonnes a year. The term "fish market" can also refer to the process of fish marketing in general, but