Mollusks

What are Mollusks?

Mollusks are a diverse group of invertebrates that include species like snails, clams, and octopuses. They often have a soft body and, in many cases, a hard external shell, playing key roles in aquatic food webs and nutrient cycling.

Soft-Bodied Animals

Mollusks are animals with soft bodies, and many have hard shells for protection. They live in a variety of places, including oceans, rivers, and lakes. Mollusks include animals like clams, snails, squid, and octopuses. They come in all shapes and sizes, from tiny sea snails to giant squids!

Types of Mollusks

There are three main types of mollusks:

• Bivalves: These mollusks, like clams and mussels, have two shells that close like a book. They live on the ocean floor or in freshwater.
• Gastropods: These include snails and slugs. Many have a spiral shell and use a “foot” to move.
• Cephalopods: Squid, octopuses, and cuttlefish fall into this group. They are smart, fast, and use tentacles to catch food.

Why Mollusks Are Important

Mollusks play a big role in aquatic ecosystems. They:

• Filter Water: Bivalves like clams clean water by filtering out tiny particles.
• Provide Food: Many animals (and humans!) eat mollusks, like oysters and squid.
• Support Ecosystems: Their shells create habitats for other animals, like small fish and crabs.

Where Mollusks Live

Mollusks can be found almost everywhere:

• Oceans: Coral reefs, sandy beaches, and deep waters.
• Freshwater: Rivers, lakes, and ponds.
• Land: Some snails and slugs live in damp places on land!

Amazing Mollusk Facts

• Octopuses can change color to blend into their surroundings.
• Giant squids are some of the largest animals in the ocean.
• Pearls are made inside the shells of some mollusks, like oysters.

Challenges

Pollution, overfishing, and habitat destruction threaten mollusks. For example, ocean acidification makes it harder for shelled mollusks to build their protective shells.