Octopus Trivia Questions and Answers

Octopus trivia quiz questions with the answers.

Octopus Trivia Questions and Answers

What is an octopus?
A: The octopus is a soft-bodied, eight-limbed mollusk of the order Octopoda.

Like other cephalopods, the octopus is bilaterally symmetric with two eyes and a what?
A: A beak, with its mouth at the center point of the eight arms.

The soft body can rapidly alter what?
A: Its shape, enabling octopuses to squeeze through small gaps.

What do they trail behind them as they swim?
A: Their eight appendages.

The siphon is used both for respiration and for what?
A: Locomotion, by expelling a jet of water.

Octopuses have a complex what?
A: Nervous system.

They have excellent sight, and are among the most what?
A: Intelligent and behaviorally diverse of all invertebrates.

Octopuses inhabit various regions of the ocean, including coral reefs, pelagic waters, and what?
A: The seabed.

Most species grow fast, mature early and are what?
A: Short-lived.

During breeding, the male uses a specially adapted arm to do what?
A: Deliver a bundle of sperm directly into the female's mantle cavity.

After delivering the bundle, what happens to him?
A: He becomes senescent and dies.

The female deposits fertilized eggs in a den and does what?
A: She cares for them until they hatch, after which she also dies.

All octopuses are venomous, but only what octopuses are known to be deadly to humans?
A: Blue-ringed octopuses.

Octopuses appear in mythology as sea monsters like the “what” of Norway?
A: The Kraken.

A battle with an octopus appears in what Victor Hugo book?
A: Toilers of the Sea.

Octopuses appear in Japanese erotic what?
A: Art, shunga.

The Giant Pacific octopus is often cited as the what?
A: Largest known octopus species.

Adults usually weigh how much?
A: Around 15 kg (33 lb).

How big is their arm span?
A: Up to 4.3 m (14 ft).

How heavy was the largest specimen of this species to be scientifically documented?
A: It was an animal with a live mass of 71 kg (156.5 lb).

The two rear appendages are generally used to do what on the sea floor?
A: Walk.

What are the other six used for?
A: Forage for food.

The bulbous and hollow mantle is fused to the back of the head and is known as what?
A: The visceral hump.

What does it contain?
A: Most of the vital organs.

The mantle cavity has muscular walls and contains the what?
A: The gills.

The mantle cavity is connected to the exterior by what?
A: A funnel or siphon.

Where is the mouth of an octopus located?
A: Underneath the arms.

Most of an octopuses body is made of soft tissue allowing it to what?
A: Lengthen, contract, and contort itself.

Lacking skeletal support, the arms work as muscular hydrostats and contain what kind of muscles?
A: Longitudinal, transverse and circular muscles around a central axial nerve.

They can extend and contract, twist to left or right, bend at any place in any direction or be held what?
A: Rigid.

The interior surfaces of the arms are covered with what?
A: Circular, adhesive suckers.

The suckers allow the octopus to anchor itself or to do what?
A: Manipulate objects.

Each sucker is usually circular and bowl-like and has what two distinct parts?
A: An outer shallow cavity called an infundibulum and a central hollow cavity called an acetabulum.

Both of which are thick muscles covered in a what?
A: A protective chitinous cuticle.

When a sucker attaches to a surface, the orifice between the two structures is what?
A: Sealed.

The eyes of the octopus are large and are located where?
A: At the top of the head.

They are similar in structure to those of a what?
A: Fish.

The cornea is formed from what?
A: A translucent epidermal layer and the slit-shaped pupil forms a hole in the iris.

The lens is suspended behind the pupil and what covers the back of the eye?
A: Photoreceptive retinal cells.

The pupil can be adjusted in size and a retinal pigment does what?
A: It screens incident light in bright conditions.

Some species differ in form from the typical what?
A: Octopus body shape.

Octopuses have a closed circulatory system, in which the blood remains where?
A: Inside the blood vessels.

Octopuses have how many hearts?
A: Three.

What are they?
A: They have one systemic heart that circulates blood round the body and two brachial hearts that pump it through each of the two gills.

The systemic heart is inactive when the animal is doing what?
A: Swimming and thus it tires quickly and prefers to crawl.

Octopus blood contains what copper-rich protein to transport oxygen?
A: Haemocyanin.

This makes the blood very viscous and it requires considerable pressure to what?
A: Pump it round the body.

Octopuses' blood pressures can exceed what?
A: 75 mmHg.

In cold conditions with low oxygen levels, haemocyanin does what?
A: It transports oxygen more efficiently than hemoglobin.

The haemocyanin is dissolved in the plasma instead of what?
A: Being carried within blood cells, and gives the blood a bluish color.