What prey defenses have evolved in fish in response to predators like sharks?

Fish have evolved several defenses against predators like sharks, including physical adaptations such as streamlined bodies for quick escape and protective body coverings like scales or spines. Behavioral strategies, such as schooling to confuse predators or diving into deeper waters, also enhance their chances of survival. Additionally, some species possess chemical defenses that can deter predators, such as toxins or unpleasant tastes. These adaptations collectively improve fish resilience in predator-rich environments.