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 sperm whale (Physeter macrocephalus), or cachalot, is the largest of the toothed whales and the largest toothed predator. It is the only living member of genus Physeter, and one of three extant species in the sperm whale family, along with the pygmy sperm whale and dwarf sperm whale of the genus Kogia.top the whale's skull is positioned a large complex of organs filled with a liquid mixture of fats and waxes called spermaceti. The purpose of this complex is to generate powerful and focused clicking sounds, which the sperm whale uses for echolocation and communication.