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, known to science as Physeter macrocephalus, is the largest of the toothed whales, which includes other members such as the dolphin and killer whale. These whales get their name from the oily fat, known as spermaceti, which is contained in their large heads.s with all whales, sperm whales are mammals and require air to breathe. They are one of the deepest diving mammals in the world, and are able to stay underwater for up to two hours before coming up for air. A sperm breaches the surface of the water to grab a breath of fresh air.