Nautiluses control their buoyancy by a. adjusting salt...

Nautiluses control their buoyancy by
$a$. adjusting salt concentrations in their blood.
$b .$ forcibly expelling water from the mantle.
c. pumping water and gases in and out of internal chambers.
$d .$ using the complex sensory organs in their heads.
$e .$ swimming rapidly.

Key Concepts

Buoyancy Control

This is the mechanism by which organisms regulate their density to achieve neutral buoyancy, allowing them to maintain a desired depth without constant swimming. It involves balancing the internal density with that of the surrounding fluid to control vertical movement in the water column.

Internal Fluid and Gas Regulation

Many aquatic organisms adjust their overall buoyancy by regulating the composition of their internal chambers. By selectively pumping water and gases in and out of these compartments, they can finely tune their density, making it easier to ascend, descend, or remain neutrally buoyant in their environment.

Transcript

00:01 Okay, the organism that we're talking about in this question is a nautilus.

00:15 So let's learn a little bit more about nautilus to answer this.

00:21 Nautilus are cephalopods.

00:28 So they fall under our phylamalusca of invertebrate animals.

00:34 So other shell animals, snails, clams.

00:39 Cepha is head.

00:42 It means head, pod.

00:44 Is meaning foot, so head foot, really because those arms and tentacles are technically their foot, and it's located on the head portion for this group of mollists.

01:01 So it includes squid, octopus, and some then they are, are those organisms, clams, and oysters, and snails have shells.

01:15 Our nautilus is still a shelled animal.

01:18 The other organisms like our squid and octopus have lost or reduced shells in their body.

01:28 They have an ex current siphon that allows the animal to control the water content.

01:48 They can eject that water and enable them to move.

01:57 So they catch their prey with those tentacles and arms.

02:13 Our nautilus has this shell.

02:19 It has this one opening.

02:21 So it's kind of like, so there's its shell.

02:28 Got these rows.

02:30 And then out from this shell, it's eyes, and then the tentacles or their arms that come out.

02:43 I have this kind of hood that protects them.

02:52 So they kind of look like a squid that's surrounded by a shell here.

02:57 So they're the only group that still retains their shell of the ancestral in this.

03:01 And you can see i drew some lines here because they have a chambered shell...

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