MEANING:
BLOW: Passage for air
HOLE: Cavity
DEFINITION:
" Blow hole is a cavity , used by underwater mammals for the purpose of breathing ".
EXPLANATION:
Whales are not fish. Hence, the don't have gills to breath. Whales are
sea mammal and have
lungs for breathing just like us. Being mammal, they require surface oxygen for which they use their blow holes. Blow holes perform function of
breathing in whales.Blow holes are
breathing holes (nostrils) which are present at the
top of the head (dorsal side) on whales.
These nostrils help them to breath in air when they came up to or near to the water surface. These nostrils get closed underwater to prevent water from entering into the holes. Using blowholes, whales can
hold their breath for a long time underwater before surfacing to breath again. The windpipe in whales is connected to the blowhole due to which they can open their mouth underwater without drowning in water.
NUMBER OF HOLES :
Smaller whales have one (1) blowhole while larger ones have two (2), as they require more oxygen.
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| Whale using its blowhole to breath. | |
