Phylum Mollusca is a diverse group of invertebrates that includes animals such as snails, clams, squid, and octopuses. These organisms can be distinguished from other invertebrates by the presence of a mantle and a non-segmented body.

The mantle is a unique characteristic of mollusks that sets them apart from other invertebrates. It is a specialized tissue layer that covers the body and extends out to form a protective covering called a shell in many mollusks. The mantle plays a crucial role in the formation of the shell, as it secretes calcium carbonate and other materials that harden to form the shell. However, not all mollusks have a shell, as some have lost this characteristic through evolution.

The non-segmented body is another distinguishing feature of mollusks. Unlike segmented worms or arthropods, mollusks have a body that is not divided into distinct segments. Instead, their body is typically soft and muscular, allowing for movement and flexibility. This non-segmented body plan is characteristic of all mollusks, regardless of whether they possess a shell or not.

The presence of a mantle and a non-segmented body are key defining characteristics of Phylum Mollusca. These features are shared by all mollusks, regardless of their specific adaptations or variations within the phylum. By having a mantle, mollusks are able to secrete a protective shell, which provides support and protection. The non-segmented body allows for efficient movement and flexibility, enabling mollusks to adapt to different environments and lifestyles.

In summary, Phylum Mollusca can be distinguished from other invertebrates by the presence of a mantle and a non-segmented body. These characteristics are unique to mollusks and play important roles in their biology and ecology.