High Quality Content by WIKIPEDIA articles! Oceanitinae is one of two subfamilies of storm-petrels. Because the distribution of the subfamily is predominantly in the southern hemisphere they are sometimes known as the southern storm-petrels. The subfamily contains five genera in which there are eight species. They were the second group of storm-petrels to break off from the ancestral petrel stock, and for this reason some authors have suggested that they should constitute a separate family from the Hydrobatinae storm-petrels.