Why do dolphins have blowholes?



  • Dolphin is the most common and very well known aquatic animal.
  • Unlike most fishes found in sea, dolphin are identified as the aquatic mammal under the order of Artiodactyla.
  • Dolphins size can range from the smallest size of 1.7 meter long to the biggest size if about 9.5 meter long.
  • Dolphins are found to leap outside the water very frequently, their leap can sometimes be of 30 feet approx.
  • Some dolphins are said to travel at the speed of 29 kilometers per hour.
  • Majority species of dolphins are said to prefer the warm water climate, however, some exceptional species of dolphins are also found in the cold water climate.
  • The anatomy or the external features if the dolphin can be classified as the torpedo-shaped body, non-flexible neck, limbs modified into flippers, a tail fin and a bulbous head.
  • Dolphins are found to have a layer of fat, under the skin to keep warm in cold conditions.

Why do dolphins have a blowhole?

  • The way we have our nostrils, the nostrils of the dolphins are said as blow hole.
  • Their prime function is to help in respiration.
  • They are situated at the top of their head so that it can be easy for respiration.
  • Dolphins are the aquatic mammals and have similar characteristics like us for respiration.
  • Their lungs are also filled with air, and they do not consists of any gills for respiration through water.
  • While swimming, the dolphin can get its part of oxygen from the air by just keeping its head on the surface of water.
  • Once the intake of air is completed, this blowhole is tightly sealed by the muscles to prevent the entry of any water in it.
  • When a blowhole is exposed to the surface above water, there is the release of air from the blowhole before raking up the new air for respiration.

Fun Facts:

  1. A dolphin is known to hold its breath for the average amount of time of 5-7 minutes.
  2. Unlike human being, dolphin has a separate tract for both the passage of food and for the intake of air. They cannot breathe like us from the mouth.
  3. Dolphins are found to have greater amount of blood in them as compared to the human beings. This increasing blood helps them to maintain higher oxygen level in them.

Related Questions:

  1. Who are the predators of dolphin?
  2. What all are the prey of dolphin?
  3. Who are the ancestors of dolphin?

True or False:

  1. Dolphins are the aquatic mammals.
  2. Dolphins breathe through the gills.
  3. Dolphins have flexible neck.
  4. Dolphins are found to have layer of fat to control their body temperature.
  5. Dolphins have their lungs filled with water.

Objective Quiz:

  1. Dolphins are the _______.
    1. Aquatic mammal.
    2. Land mammal.
    3. Reptiles.
    4. Aves.
  2. The smallest size of dolphin is found to be about ______.
    1. 1.7 meter.
    2. 1.4 meter.
    3. 1.3 meter.
    4. 1.6 meter.
  3. Dolphins can leap up to ______.
    1. Thirty feet.
    2. Twenty feet.
    3. Ten feet.
    4. Fifty feet.
  4. _______ is present above the head.
    1. Blowhole.
    2. Spine.
    3. Fins.
    4. Gills.
  5. _______ are modified into flippers in dolphin.
    1. Limbs.
    2. Eyes.
    3. Fins.
    4. Gills.

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