Euphausiacea, commonly known as krill, are small, shrimp-like crustaceans found in oceans worldwide. They play a crucial role in marine ecosystems, serving as a primary food source for various marine animals, including whales, seals, and fish. Krill are characterized by their transparent bodies and are typically found in large swarms. These organisms are vital for the ocean's food web and contribute significantly to the global carbon cycle. Euphausiacea feed on phytoplankton and are known for their ability to reproduce rapidly, making them an essential component of marine biodiversity and a key indicator of ocean health.