Mollusks make up the phylum known as Mollusca. Around 23% of all marine life is comprised of mollusks. Some examples of organisms that are from the Mollusca phylum includes octopuses, snails, and clams.
Characteristics:
The most notable characteristic of a mollusk is its mantle that is used for breathing and excretion. This mantle overlaps the body with a small amount of spare room to fit the mantle cavity. Mollusks also have anuses and genitalia that open into this mantle cavity. All Mollusks have two main pairs of nerve cords as well.
Amphioctopus marginatus (Coconut Octopus):
Octopuses do not have an external skeleton let along an internal skeleton. In some species, an octopus can have some kind of shell in their mantle. They move around by crawling or swimming, using their 8 large arms. these arms have suction cups which they can grip onto things with and pull themselves forward. Or they quickly bring all of their arms together. This will propel them forward face first.
Octopuses do not have an external skeleton let along an internal skeleton. In some species, an octopus can have some kind of shell in their mantle. They move around by crawling or swimming, using their 8 large arms. these arms have suction cups which they can grip onto things with and pull themselves forward. Or they quickly bring all of their arms together. This will propel them forward face first.
Helix Pomatia (Roman Snail):
A snail is protected by a large shell that surrounds a majority of its body. This shell acts as an exoskeleton in the way that it protects the snail along with giving it shelter. A snail propels itself forwards by secreting mucus from its foot muscle and then contracting that muscle. This allows it to move across the ground or up/down steep surfaces.
A snail is protected by a large shell that surrounds a majority of its body. This shell acts as an exoskeleton in the way that it protects the snail along with giving it shelter. A snail propels itself forwards by secreting mucus from its foot muscle and then contracting that muscle. This allows it to move across the ground or up/down steep surfaces.
Mercenaria mercaneria (Hard Clam):
A clam has a rigid external covering for the body known as an exoskeleton. It is used to support and protect the clam. Its skeleton is comprised of two shells connected by a hinge-like joint known as the "umbo". A clam can move across the ocean floor by using its foot that it slips out of its shell, sticks it into the ground, then pulls itself forward.
A clam has a rigid external covering for the body known as an exoskeleton. It is used to support and protect the clam. Its skeleton is comprised of two shells connected by a hinge-like joint known as the "umbo". A clam can move across the ocean floor by using its foot that it slips out of its shell, sticks it into the ground, then pulls itself forward.