The blue whale is the biggest animal on the planet growing up to 30m and weighing 160 tonnes. they can eat nearly 4 million krill in a single day.It lunges into a shoal of prey and it's throat swells to four times the normal width.it closes it's mouth,expels the water and swallows the thousands of food items retained by the baleen.female blue whales give birth to the biggest in the world.The calf is 7m (23ft) long,2.5 tonnes in weight , and is suckled for 6-8 months.These massive giants can produce a noise so loud it can rival a rocket.which at volumes greater than 180 decibels are the loudest of any creature sounds.