Question

The molluscan without a shell is:
A. Sepia
B. Octopus
C. Loligo
D. Nautilus

Answer 1

Hint: The animal has been regarded as one of the few intelligent non- human species. Shells are protective adaptations by most of the soft-bodied organisms such as mollusks. They are made of calcium carbonate and numerous fluorapatite

Complete answer: Octopoda is the scientific name of octopuses.
1. They are highly intelligent marine mollusks that have the ability to camouflage.
2. They are also under intense scientific study for their ability to modify their shape to escape from predators. They do so by producing dermal projections and varying the density of the pigment cells on their skin surface.
3. They do not have a shell, but they have other defense mechanisms as stated above.
4. They also have the ability to synthesize and squirt a bluish violet ink to mask their presence when a predator is nearby.
5. The only calcified part of their body is their strong teeth. They are strong, three forceps like projections between their tentacles.
6. They have three hearts, eight tentacles (each with several sticky cusps and photoreceptors), and not bones. The lack of bones enables them to pass through tiny apertures and enclose themselves in minuscule objects for survival.
7. Some octopuses are highly venomous.
Ex: Blue-ringed octopuses found along the coasts of Australia is a genus of 4 highly venomous octopuses that have killed several surfers.

So the correct answer is B.

Note: Loligo forbesii is the scientific name of veined squid and long-finned squid.
Sepiida is the scientific name of cuttlefish.
Nautilidae is a member of the cephalopod family, they are known for their chambered shell which corresponds to the Fibonacci sequence.
Squids and cuttlefishes have an internal skeletal system base of cuttlebones.
Several other members of the cephalopod family also lack an external calcified membrane/ shell.