When compared with moms who had difficult deliveries ending in vaginal birth, women in the study who had cesarean deliveries said they had more problems getting pregnant after the birth of their first child.
Whale is the common name for a widely distributed and diverse group of fully aquatic marine mammals. They are an informal grouping within the infraorder Cetacea, excluding dolphins and porpoises, so to zoologists the grouping is paraphyletic.dontocetes feed largely on fish and squid. A few, like the sperm whale, feed on large invertebrates, such as giant squid. Grey whales are specialized for feeding on bottom-dwelling molluscs. Male whales typically mate with multiple females every year, but females only mate every two to three years.
But still, orcas are dolphins. As a matter of fact, they are the largest of the dolphin species growing to lengths in excess of 30 feet. Next to man, orcas are the most widely distributed mammal on Earth. In all, there are over 80 species of whales living in our world today. These 80 species of whales make up the classification order known as Cetacea. What is a Cetacean? Cetacean is the Latin name for whale. A Cetacean is a whale which belongs to the family known as Cetacea. Cetacea contains two suborders: Mysticeti and Odontoceti Baleen whales (whales without teeth) are members of the Mysticeti suborder. 1  Toothed whales, like the sperm whale, along with all the dolphins and porpoises, make up the suborder Odontoceti. 2  Altogether, the two suborders contain over eighty known species, further separated into thirteen different families.