Digestive system of humpback whales stretching like an accordion. They allow whales to open their mandible to 90 degrees to gulp water and prey. They expel saltwater through the baleen plates, leaving behind krill and plankton. The whale's tongue plays a vital role in filter feeding, as it is used to push the water out of its mouth while keeping the prey trapped in its baleen bristles. As humpback whales do not have teeth, their food is swallowed whole and travels down the esophagus into the preliminary stomach (known as the forestomach) to be ground. Baleen whales have a multi-chambered stomach, divided into three distinct
Whale conservation certain other species of high intelligence: humans, other great apes, bottlenose dolphins and elephants. There is an argument that whales should not be killed because of their high intelligence. Pro-whalers claim that pigs also possess high intelligence, and are routinely butchered and eaten, and that intelligence should not be the determining factor of whether an animal is acceptable to eat or not. Whale meat products from certain species have been shown to contain pollutants such as PCBs, mercury, and dioxins. Levels of pollutants in toothed-whale products are significantly higher than those of baleen whales, reflecting the fact that toothed whales