포유류중 가장 깊이(3 km, 300기압을 느끼게 된다) 길게(1시간 반) 잠수하는 동물.
향유고래는 머리부분에 경랍이라는 납과 같은 물질이 있는데, 잠수 직전에 차가운 바다물을 유입시켜 경랍을 고체화 시키면 약 40kg에 해당하는 힘을 얻을수 있어 수직하강과 같은 잠수를 가능하게 한다고 한다.
갑자기 인류가 동물들과 좀더 친화적이였다면 지금쯤 어땠을까 하는 생각을 해본다.
, are the deepest-diving mammals.
Sperm whales are believed to be able to reach 3 kilometres (1.9 mi) and
remain submerged for 90 minutes.
More typical dives are around 400 metres (1,300 ft) and 35 minutes in
duration.
and drown.
The sperm whale has adapted to cope with drastic pressure changes
when diving. The flexible ribcage allows lung collapse,
reducing nitrogen intake, and metabolism
can decrease to conserve oxygen.[23][24]
Myoglobin,
which stores oxygen in muscle tissue, is much more abundant than in
terrestrial animals.[25]
The blood
has a high red blood cell density, which contain
oxygen-carrying hemoglobin. The oxygenated blood can be directed
towards the brain and other essential organs only when oxygen levels
deplete.[26][27][28]
The spermaceti organ may also play a role by adjusting buoyancy
(see below).[29]
While sperm whales are well adapted to diving, repeated dives to
great depths have long term effects. Bones show pitting that signals decompression sickness in humans.
Older skeletons showed the most extensive pitting, whereas calves showed
no damage. This damage may indicate that sperm whales are susceptible
to decompression sickness, and sudden surfacing could be lethal to them.[30]
Between dives, the sperm whale surfaces to breathe for about eight
minutes before again diving.[4]
Odontoceti (toothed whales) breathe air at the surface through a
single, S-shaped blowhole. Sperm whales spout (breathe) 3–5 times per
minute at rest, increasing to 6–7 times per minute after a dive. The
blow is a noisy, single stream that rises up to 15 metres (49 ft) above
the surface and points forward and left at a 45° angle. On average,
females and juveniles blow every 12.5 seconds before dives, while large
males blow every 17.5 seconds before dives.[31]
Spermaceti
functions
The spermaceti organs may help adjust the whale's buoyancy.
Before diving, cold water enters the organ and the wax solidifies.[29][37]
The increase in specific density
generates a down force of about 40 kilograms (88 lb)[clarification needed] and
allows the whale to dive with less effort. During the hunt, oxygen
consumption produces heat and melts the spermaceti, increasing its
buoyancy, enabling easy surfacing.[38]
Herman Melville's Moby Dick suggests that the "case"
containing the spermaceti evolved as a kind of battering ram for use in
fights between males.[39]
This hypothesis is consistent with the well-documented sinking of the
ships Essex and Ann Alexander by attackers estimated to weigh
only one-fifth as much as the ships.[40]
Another possibility is that the case aids echolocation (see melon).[5]
The organ's variable shape narrows or spreads the sound.[41]
The sperm whale has two nostrils. An external nostril forms the blow
hole, and an internal nostril presses against the bag-like spermaceti
container.[5]
The male's spermaceti organ is much larger than the female's. This may
be a case of sexual selection, enabling males to compete
for females using sound displays.[42]
