odontocetes

Echolocation allows odontocetes to pursue agile prey, even in dark or murky waters. Porpoises and dolphins produce ultrasonic clicks by forcing air between the phonic lips in their nasal passages. The lips open and close, which causes the nearby tissue to vibrate and create sound waves. These bounce off the bony cribriform plate at the front of the skull and are then focused into a beam by the melon, which the cetacean aims at the prey. Dolphins use the melon, an oily lump of tissue behind the forehead, to focus their sound waves into a beam. Echoes returning from an animal or object are transferred through oil filled sinuses in the lower mandible to the left ear. Sperm whales (Physeter macrocephalus) have a different anatomy for producing echolocation clicks. The left nasal passage is used for breathing, while the right is for sound production. Sound waves pass through an oil-filled spermaceti organ, rebound off an air sac at the rear of the head, and are focused into a beam of sound through many fatty lenses. Experiments with bottlenose dolphins (Tursiops truncatus) show that they can identify submerged objects by size, shape, composition, and many other factors. This allows then to learn the echo signatures of their preferred prey species. Dolphins also make an array of low frequency sounds to communicate with each other, like whistles and squeaks. Each dolphin has a signature whistle. The picture shows a long beaked common dolphin (Delphinus capensis) hunting fish during the sardine run. Photo source here.

I had this picture sent to me by @sailanocean, and it was too mystical not to share! Humpback whales and other mysticetes often receive less attention than the odontocetes, but they are certainly fascinating and deserve to be celebrated just as much. This image was taken off of Haida Gwaii in July, 2015!
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Photo credit to @sailanocean; thanks for sharing!

If you have a marine image you’d like to share, feel free to submit it via direct message and I will post it if appropriate ☺ by wildforwhales http://ift.tt/1SpgBe3