Starfish are not mollusks. Mollusks are characterized by soft and unsegmented bodies, such as snails, conches and squid. The body structure of starfish is different from that of mollusks. It belongs to echinoderms, which have very different appearances. Besides starfish, there are sea urchins, sea cucumbers and sea snake tails. Besides star-shaped, there are spherical, cylindrical and flower-shaped. Echinoderms usually live underwater and have strong regeneration ability.

1. Conch: Conch is a common marine mollusk, belonging to gastropods, and its shell edge is square, and it is very strong and thick, with a height of 10 cm. Its activity is slow, and it often feeds on seaweed and tiny organisms. It generally inhabits shallow sea areas and likes to eat echinoderms. The outer lip of the shell is extremely abducted, and the size of the female snail is obviously larger than that of the male snail.

2. Shellfish: Shellfish are a class of mollusks, which are divided into different species according to different living waters. Some live in salt water, such as the sea, or in fresh water, such as rivers and streams. There are many varieties of it, including red shellfish, salamander, snail, conch, clam, clam and so on.

3. Squid: Squid is also a mollusk, with conical body, pale body color, light brown spots, large head and 10 touching feet in front. It often moves in the middle and upper layers of shallow sea, and its vertical movement range can reach more than 100 meters. It feeds on krill, sardines, silverfish, small male fish, etc. It is also the hunting object of fierce fish.