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 drum Fish drum The fish drum () is a Chinese percussion instrument. The name actually designates two rather different instruments, a membranophone and an idiophone. The membranophone fish drum is the symbol of Elder Zhang Guo, one of the Eight Immortals. This drum is a long and slender piece of bamboo with a dried fish skin stretched over one end. Two smaller pieces of bamboo resembling golf clubs are used as Castanets. There is also the idiophone, which is also called a wooden fish. This type of fish drum is used to accompany performers of "changben" or Chinese narrative ballads. They