Octopus is a general term for 252 species of marine mollusks belonging to 26 genera in the family Octopodidae. As a temperate mollusk, it lives underwater and is adapted to a water temperature of no less than 7 ℃, with a seawater density of 1.021 being the most suitable. It will die in low salinity environments. It can grow by feeding on large animal plankton. Widely distributed in tropical and temperate oceans around the world. This family is an important commercial cephalopod, with a certain production of true octopuses (common octopuses) along the southern coast of China and short octopuses along the northern coast. The dried products of octopus are called "Eight Octopus Dried" or "Octopus Dried". In addition to consumption, they also have the effects of nourishing blood, qi, and astringent muscles in medicine.

Nautiloidea: A general term for marine mollusks in the family Nautilidae, belonging to the order Cephalopoda. There are 2 genera and 6 species with curled pearl like shells. The parrot snail has undergone hundreds of millions of years of evolution on Earth, but its appearance, habits, and other changes are minimal. It is known as a "living fossil" in the ocean and has high value in studying biological evolution and paleontology. It also holds a place in biomimetic science. In 1954, the United States developed the world's first nuclear submarine, the Nautilus, which was launched in Groton, USA.