The Dugong By Brittany McCane

Classification Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Sirenia Family: Dugongidae Subfamily: Dugonginae Genus: Dugong Species: D. dugon Evolutionary Path/ Origin Sirenias have existed for 50 to 60 million years. They are thought to have branched off from the Proboscidea (elephants) during the Palaeocene, when the group’s earliest known representativ, a pig- sized prorastomid from Jamaca in the early Eocene, entered the water. By the middle Eocene, protosirenid sea cows were abundant in North America, Europe, and Asia. The Dugongidae first appeared in the mid-late Eocene of the Mediterranean region. The manatees (Trichechidae) are the Dugong’s closest living relatives..

Habitat Dugongs live in warm coastal waters of the Indo-Pacific region from the Western Pacific Ocean to the Eastern coast of Africa, along an estimated 140,000 kilometers of coastline between 26 and 27 degrees to the North and South of the equator, notably in Shark Bay and along the North coat to Moreton Bay. Feeding Habits They are a strictly marine herbivorous mammal that depends heavily upon sea grasses for subsistence. Adults can eat up to 88 pounds of sea grass daily. Before swallowing, it shakes its head to eliminate sand from the food.

Status The Dugong is an endangered species. It is one of only four extant sirenian mammals, and there are only 2,252 of them left. This is due to floods and cyclones destroying sea grass, coastal development decreasing their habitat, and incidental morality through commercial gillnets, entanglement in shark nets, collisions with boats, and hunting. Reproduction Dugongs reproduce viviparously. They reach sexual maturity between the 9 th and 15 th year. Males establish and protect their courtship territory. Pregnancy lasts one year and ends with one calf. Females give birth very 3 to 7 years. The bond between mother and her calf is very strong. She helps it reach the surface for its first breath and it usually stays with her until the age of 18 months.

Random Facts Dugongs have a flat tail and flippers like a whale, but it is more closely related to an elephant they breathe using lungs and must surface every 6 minutes to breathe when in shallow water, they can “stand” on their tails with their heads above the water’s surface they communicate using barks, chirps, squeaks, and trills they normally swim at 6 miles an hour, but can accelerate to 14 miles an hour when it needs to males develop tusks during puberty, at an age between 12 and 15 years they can survive for up to 70 years in protected habitats with enough food sources they can reach a length of 11 feet and weigh up to 2,000 pounds they have a large mouth with an upper lip designed for bristling sea grass

Artistic Depiction This is a poem about the Dugong They eat sea grass all day long They are cousins of the manatee And are known as the cows of the sea They live in the Indian and Pacific oceans And usually swim at six mph when in motion They reproduce viviparity The same as humans like you and me They’ve been around for over 50 million years But if we don’t save them, we’ll be in for tears Human development is destroying their food And they’re killed by propellers and our careless attitudes Commercial fishing nets are a problem too Though that’s probably not surprising to you You can go online to learn more At savethedugong.org

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