The Petrels (Procellariidae) comprise 84 species of tube-nosed seabirds, belonging to five subfamilies:
-Gadfly Petrels (Pterodrominae)
-Fulmars (Fulmarinae)
-Prions (Pachyptilinae)
-Procellarine petrels (Procellariinae)
-Shearwaters (Puffininae)

All species are exclusively pelagic in distribution — returning to land only to breed. The word "petrel" comes from the Latin name for the Christian Saint Peter, and refers to the habits of certain species to hover just above the ocean waves, with their feet barely touching the water, thus giving an appearance of walking on water, as St. Peter is said to have done.