Marine Biology

Sensory Systems

       Pinnipeds have large eyes for seeing in the low light conditions often found underwater. In cetaceans, the eyes are located on the sides of the head, but focus forward. Both the pinniped's and cetacean's eyes are adapted to see well underwater. As a result, their in-air vision suffers. Manatees have small eyes and fair to poor eyesight. They seem to be farsighted and rely on touch to identify objects close by.

       Pinnipeds have small olfactory (sense of smell) lobes, and evidence shows that smell is important when interacting with other pinnipeds. Toothed whales do not have a sense of smell, but baleen whales do have some olfactory nerves. Cetaceans have taste buds at the base of their tongue, and the common dolphin and the bottlenose dolphin are able to distinguish  certain smells. Manatees have a good sense of smell and are often selective in their food choices. Sirenians have many more taste buds than   cetaceans , and this may contribute to their choices of food. Polar bears have an acute sense of smell, and it is the most important sense for detecting prey on land. A polar bear can smell a seal  present in a far off location with more than 20 miles apart.