Blue Whale

Scientific name    Balaenopter musculus

Gaelic name          Muc-mhara mhionc

    Fascinating Fact: The blow from a blue whale can be 9m high!

The blue whale is the largest animal ever to have lived on the Earth.  One blue whale was recorded as being more than 33 metres long and a massive 190 tonnes.  Most adults reach 24 to 27 metres in length and weigh about 120 tonnes.

That's as much as two thousand seven hundred people,and its tongue alone is heavier than an elephant!

Blue whales have a long streamlined body with a very small dorsal fin and they can swim as fast as 30 km/hour.  They dive down to about 150 metres hunting for their food which, suprisingly for such a huge animal, is very small. 

    Feeding

Blue whales feed on tiny little shrimp-like animals called krill which are found in huge numbers in some places in the oceans at certain times of the year.  So these enormous blue whales have to keep moving to find the krill.

But blue whales don't have any teeth.  They  have plates of tissue similar to your fingernails growing from their upper jaw.  These are called baleen plates and they have a hairy edge which can trap small animals in a manner a bit like a sieve or a net.  The baleen plates of a blue whale may be up to 1 metre long.  Once they have found the krill they gulp a huge mouthful of water and krill into their cavernous mouths and then force the water out through their baleen plates, catching the krill inside to be swallowed.  Krill are not easy to digest since their skeleton is on the outside and forms a hard, protective layer around them.  In order to digest the krill, blue whales have seven parts to their stomachs.

    Reproduction

Blue whales can live up to 120 years but they only have a few calves since it takes 11 months of pregnancy and then seven months of suckling.  The calf may weigh up to 4 tonnes at birth and have a length of 7.5 metres.  The milk their mother produces is 10 times as concentrated as human milk and the calf needs about 380 litres of milk a day.  It can gain as much as 100 kilograms in weight every day.

    Threats

Blue whales have been hunted almost to the point of extinction.  There are very few left so you would be very lucky if you saw one.

    Other Fascinating Facts

Blue whales travel huge distances and need to keep in touch with other blue whales across miles and miles of ocean.  To do this they produce a very, very low frequency noise.  It is very low so that it can travel more easily through the water and it is also very powerful.  Your voice can probably make a sound of 100 decibels if you shout loudly.  The sound of a jet plane is about 150 decibels and a blue whale's sound can be as loud as 188 decibels.  It is the loudest sound ever known to be produced by a living source and because it is so low it is like feeling an earthquake!

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