The golden shiner (Notemigonus crysoleucas) is a cyprinid fish native to eastern North America.
The lack of scales on the keel is important to differentiate the golden shiner from the very similar-looking rudd, Scardinius erythrophtalmus, a European species that has been introduced in a few places in North America.
[5] Golden shiners prefer quiet waters and are therefore found in lakes, ponds, sloughs, and ditches.
[13] If all fish have similar knowledge, there is still a tendency for some individuals to be found always at the front of a moving shoal, possibly because they are intrinsically hungrier and more motivated to find food.
[15] Like other minnows, golden shiners are sensitive to the release of an alarm substance, or schreckstoff, contained within special skin cells.
In the laboratory, golden shiners were found to react strongly to water that contained feces from snakes that had eaten other golden shiners, but not nearly as much to water laden with feces from snakes that had eaten green swordtails, a fish that does not possess an alarm substance.
[20] Golden shiners are also capable of time-place learning (associating different places with different times of day).
[21] Researchers have found that long-term exposure of golden shiners to methylmercury can cause disadvantageous effects in the function of the nervous, reproductive, immune, and endocrine systems as well as in behavior.
[22] For example, golden shiners exposed to methylmercury showed a decline in reproduction through the inhibition of hypothalamus, pituitary, and gonadal function.
[24] Fish exposed to high amounts of mercury showed signs of delayed shoaling after exposure to predators.
[24] These fish took up to nearly three times longer to return to pre-exposure behaviors compared to other groups exposed to lower amounts of mercury.