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.
The word rorqual means tube whale or furrowed whale, referring to the pleats on the lower jaws of rorquals. All rorquals have baleen, a dorsal fin and throat grooves. Other members of this family include the humpback whale, fin whale, and minke whale. The blue whale's scientific name is Balaenoptera musculus. Its generic name, Balaenoptera, means winged whale, which refers to the blue whale's dorsal fin. The blue whale's specific name, musculus, means little mouse. The blue whale is currently the largest extant animal. Blue whales may exceed 100ft in length and 100 tons in weight. Female blue whales are usually larger than males of the same age.