Dolphins

Eating
Dolphin hunting ways are different, but overall they eat fish and octopus, except narwhals and small narwhals which eat small mammals as well.
Most common hunting way is surpessing fish hordes. Then dolphins swim through the horde easily catching all the fish. 
It's not rare to see dolphins help humans fishing. Dolphins make fish move closer towards human's nets and then signalize humans that fish are in the net. Dolphins then eat the remaining fish or the fish that fell out of the net. It is some kind of human and dolphin symbiosis.

Reproduction
As dolphins are mammals, their reproduction way is same as humans.
Pregnancy period usually lasts 1 year.

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