A beach comber has found a weird looking, triangular shaped skull washed up on a beach near Pelican in Southeast Alaska. It's about the size of her hand and it's not bone, it's cartilage, and it looks like shiny white plastic. It belongs to a skate - a manta ray-like fish related to sharks. Like manta rays and sting-rays, skates have cartilaginous skeletons, flat bodies and wing-like fins. They are bottom-dwellers and eat crabs, clams, worms, and fish. They are slow-growing, long-lived animals, and take about 11 years to become sexually mature.
Skates are found in oceans throughout the world. Skates differ from rays because they lay eggs instead of bearing live young - and they don't sting. There are 14 species of skates in Alaska waters.
Skates congregate by the thousands to lay their eggs in ocean bottom nurseries; generally in June and July. Some nurseries are 500 feet to 1,200 feet deep and may contain millions of egg cases in various stages of development. These nursery sites are usually located at the heads of undersea canyons, where water temperatures are constant throughout the year. A skate may lay just 25 eggs, every other year, and eggs can take from one to four years to gestate on the sea floor before they finally hatch.
Unlike some fish, which lay thousands of eggs every year, with only a small fraction of the young surviving to adulthood; skates have a low reproduction rate but the young tend to have high survival rates.