Mollusks For Childs | Learn all about these land and sea dwellers

Do you know what a mollusk is? If you said snail, you'd be right, but not fully. In this video for kids, you'll learn that snails are just one member of the Mollusca phylum. In fact, you'd discover that snails and clams and octopuses are RELATED! They're all mollusks of some kind. There are three main groups—gastropoda (snails), bivalvia (clams, oysters, and mussels), and cephalopoda (squid and octopuses).

Gastropoda is the most diverse group. These are the snails, and there are tens of thousands of them. Almost all snails grow shells in one spiraled piece. But there are some that stopped growing shells; these are what we call slugs! Bivalvia have two shells instead of one, which is why clams, oysters, and mussels are part of this group. Cephalopods only live in salt water, which is why you wouldn't find squid and octopuses living on land. They don't have shells either as most other mollusks do. This group is fast, larger, and more intelligent than the other two groups.

Scientists have discovered about 100,000 species of mollusk all over the world, but there are still many more out there to be found. There are probably tens of thousands of undiscovered mollusks! These animals are either terrestrial (on the land) or aquatic (in the water). Most live in the salty ocean water, but some live in freshwater. Mollusks are invertebrate animals, which means they do not have a backbone and are cold-blooded.

Mollusk
Mollusca phylum
Snails
Clams
Octopuses
Gastropoda
Bivalvia
Cephalopoda
Slugs
Oysters
Mussels
Squid
Marine animals
Invertebrates
Cold-blooded
Aquatic animals
Terrestrial animals
Shells
Saltwater
Freshwater
Species diversity
Marine biology