There are more than 30,000 known species of fish, and the class displays incredible diversity: from cute seahorses and grumpy-looking moray eels to graceful sharks. But, as a food source for other animals, fish also play a crucial role in aquatic ecosystems and can affect the delicate balance of complex food webs. Their diversity and adaptability make them an important part of life on our planet. Many fish species are endangered as a result of pollution, overfishing and habitat loss. Protecting fish species and their habitats is a crucial part of preserving the biodiversity and health of our oceans.