Decapoda
Shrimp, krill, and prawns are small to medium-sized, marine crustaceans that belong to the order Decapoda (shrimp and prawns) or the order Euphausiacea (krill).
They have a hard exoskeleton and five pairs of legs, and can be found in a variety of colors and sizes. Shrimp and prawns can grow up to about 8-10 inches in length, while krill are smaller, growing up to about 2-3 inches in length.
Shrimp, krill, and prawns are found in the oceans all around the world, in both shallow and deep waters. They inhabit a variety of habitats, including coral reefs, rocky shores, sandy beaches, and muddy estuaries.
Shrimp and prawns are omnivorous and will eat a variety of foods, including plants, algae, and small invertebrates. They are also known to feed on dead animals and will scavenge for food if necessary. Krill are herbivorous and feed on phytoplankton, small plants and algae that float in the water.
Shrimp, krill, and prawns are social animals and can often be found in large groups. They use their claws and legs to defend themselves and to capture food, and some species are able to swim using their legs or by using their claws to paddle through the water. Some species of krill and shrimp are also able to produce light through a process called bioluminescence.
There are many different species of shrimp, krill, and prawns, including the giant tiger prawn (Penaeus monodon), the whiteleg shrimp (Litopenaeus vannamei), the redclaw crayfish (Cherax quadricarinatus), the Antarctic krill (Euphausia superba), the Pacific krill (Euphausia pacifica), and the Northern krill (Meganyctiphanes norvegica).
All of these species belong to the order Decapoda (shrimp and prawns) or the order Euphausiacea (krill).