166 Ocean Life 
consumed air from their lungs, they do so in a blast of vapor, 
the spout; the whale is then said to be “blowing.” 
Whales once occurred in far greater numbers than they do 
today, but they have been killed off by whalers until now 
some species are quite rare. 
Porpoises, like whales, are warm-blooded mammals. There 
are many species of them, the largest being the blackfish ~ 
variety. 
They are extremely fast in the water, often playing around 
the bow of a fast-moving vessel. At night they can be seen 
Porpoise. 
by virtue of their phosphorescent wakes, or one may detect 
their presence by their baby-like cries or coughing noises. 
Sailors regard them as friends and claim that it is bad luck 
to molest them. 
Seals mostly inhabit seacoasts and ice floes in colder parts 
of the earth, but some do occur in warmer regions. They 
feed on fish and marine animals. True seals do not have 
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