Dolphins and Porpoises

Dolphins and porpoises sure do look close,
But I’ve learned how to tell them apart.
The dolphins can whistle through blowholes to talk
With each other; they’re really quite smart.
In fairness, the porpoises’ blowholes might not
Have the structure for making that sound.
Of dolphins, some thirty-three species exist;
Of the porpoises, six are around.
And speaking of round, take a look at their faces:
The dolphin has more of a beak,
With razor-sharp teeth shaped like cones and not spades,
Plus a leaner, more streamlined physique
That is longer on average. Finally, look
At the shape of the fin on the back:
A dolphin’s is curved and a bit less triangular.
Now do you have enough facts?