Question 1

True or false: Nautiluses can jet propel themselves backward by expelling water through a siphon.

Accepted Answer

True. Like other cephalopods, nautiluses use a muscular siphon to shoot water for jet propulsion, though they are slower than squid or octopus.

Question 2

True or false: Nautiluses have up to 90 tentacles, but they lack suckers.

Accepted Answer

True. They possess many thin, sticky tentacles (cirri) without suckers, used for grasping prey and sensing the environment.

Question 3

True or false: The nautilus uses gas-filled chambers in its shell to control buoyancy, similar to a submarine.

Accepted Answer

True. By adjusting gas and liquid levels in its shell chambers via a tube called the siphuncle, the nautilus can rise or sink with precision.

Question 4

True or false: Nautiluses are found in all oceans worldwide, from shallow reefs to the deep sea.

Accepted Answer

False. Nautiluses are restricted to the Indo-Pacific region, typically in deep slopes of coral reefs, not globally distributed.

Question 5

True or false: Nautiluses can regenerate lost tentacles and even parts of their shell.

Accepted Answer

False. Nautiluses cannot regenerate shell damage; they only add new chambers. Tentacle regeneration is limited compared to octopuses, which regrow fully.

Question 6

True or false: Nautilus eyes lack lenses and work like a pinhole camera to form images.

Accepted Answer

True. Nautilus eyes are primitive and open to the sea through a tiny hole, creating a sharp but dim image, unlike the complex eyes of other cephalopods.

Question 7

True or false: The nautilus is a living fossil that has remained unchanged for over 500 million years.

Accepted Answer

False. While nautiloids date back 500 million years, modern nautilus species evolved more recently and have changed, though they look similar to ancient forms.

Question 8

True or false: Nautilus shells are made entirely of aragonite, the same mineral found in pearls.

Accepted Answer

True. The shell’s outer layer is aragonite, but inner chambers also contain nacre (mother of pearl), making it strong and iridescent.

Nautilus Trivia Questions