Sharks, Mammals and All.

We have safely cruised thru Jnr's obsession and fascination with sharks and killer whales. So far, we've learnt that killer whales are known as Orca, and that sharks are afraid of dolphins because dolphins with it's bulbous nose will attack the shark on it's soft underbelly. And that sharks are fish, because they have gills which explains that they need to continuosly swim in order to flush oxygen laden water thru their gills; and that they drown if they stop swimming- like those that got caught in fishermen nets. Most sharks lay eggs that comes in very interesting shape and sizes, but some sharks do give birth to babies.

Whales and dolphins are mammals because they have lungs, which explains that they come to the surface of water all the time to breathe. Jnr reckon that is why dolphins keeps jumping out of water when they swim- to catch their breath! And all mammals give birth to babies including these magnificent creatures.

We watched the Free Willy movie, which had us discussing why if the whale is a mammal, why can't it survive out of water? It just so happened last month, there was another great big whale beached on the River Thames, which unfortunately died despite massive effort to relocate it back to sea. This lead to discussions of the evolution and size. Which was interesting enough backed up by the Walking With Beast documentary about whales being originally aggresive predotary, snappy crocodile-like land creature which eventually evolved into this gentle creatures like the big humpback whale with thier soft fringed-like teeth. As always, Jnr is very short on attention but nevertheless his obsession allows continuous little talks and snippets here and there about whales' size, fats and bouncy, gravity and evolution.

Intersting link about whales
http://www.learner.org/jnorth/tm/gwhale/AdaptationsHead.html