Dugong dugon
Dugong [+]

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Sirenia
Family: Dugongidae
Genus: Dugong
species: Dugong dugon
+ITIS +WoRMS +Conservation Status

Description & Behavior

The dugong, Dugong dugon (Müller, 1776), aka sea cow, ranges in length from 2.4-4 m in length. Sexual dimorphism is either absent or females may slightly outsize males and can weigh over 270 kg.

Dugongs are born a pale cream color, but they darken with age to a deep slate gray dorsally and laterally. Short hair is sparsely distributed over the body, save the bristles on the muzzle. The skin is thick, tough and smooth.

The front-limbs have evolved into flippers that are 35-45 cm long. These are used for propulsion by young, but the adults use the fluke-like tail for locomotion, using the flippers for steering.

The muscular upper lip is cleft and protrudes over the down turned mouth. The premaxilla is enlarged and downturned, the nasal bones are absent, the braincase is small and the zygomatic arch is thick and deep. The bones of the skeleton are pachyostotic (extremely thickened and dense).

Although superficially they resemble whales, sirenians have evolved independently. They are thought to be descended from the group of ancient land mammals that also gave rise to the elephants.

World Range & Habitat

Pacific Ocean, Indian Ocean: dugong are found discontinuously in coastal waters of east Africa from the Red Sea to northernmost South Africa, northeastern India, along the Malay peninsula, around the northern coast of Australia to New Guinea and many of the island groups of the South Pacific. The dugong's range was much greater in the past.

Dugongs inhabit shallow, tropical marine coastal water mainly confined to sea grass beds, which occur in calm and shallow coastal areas, such as embayment and lagoons. Dugongs and are more strictly marine than manatees, they seldom enter rivers.

» GBIF occurrence data in Google Earth [Requirements | Tips] | Ocean Biogeographic Information System (OBIS) [World Map] | [about]

Feeding Behavior (Ecology)

Dugongs feed on the phanerogamous (having visible flowers containing distinct stamens and pistils) sea grasses of the families Potamogetonaceae and Hydrocharitaceae. Also reported to occasionally eat algae, and crabs have also been found in the stomachs of dugongs. Despite its diet, the dugong has a relatively simple stomach. The lower lip and distal parts of the palate (roof of the mouth) have horny pads used to grasp vegetation, which is then uprooted with the strong upper lip. Dugongs have 10-14 teeth in adults. The molars are rootless, circular in cross-section and lack enamel, males have long, tusklike incisor teeth.

Life History

Dugongs are long-lived marine mammals with life spans of up to 70 years and a minimum pre-reproductive period of 9-10 years, though it can occur as late as 15 years and an estimated mean calving interval of 3-7 years.

Breeding occurs throughout the year and peak months for birth vary geographically. The exact length of gestation is unknown, but it is presumed to be about 1 year. Single calves are the norm and twins are rare. Parturition (the birth process) takes place in shallow water and newborn calves are able to swim immediately to the surface for their first breath of air. Newborn calves are about 100-120 cm long and weigh 20-35 kg. Young may remain with the mother for a year.

Comments

Dugongs are hunted throughout their range for meat, which has been likened to veal. They are also hunted for oil, hides for leather, and for their bones and teeth, which are made into ivory artifacts and charcoal for sugar refining. Some Asian cultures prize dugong products for "medicinal" purposes.

Has been heavily exploited in the Philippines, almost to extinction.

Dugongs have a good fossil record going back to Eocene terrestrial ancestors.

The dugong, Dugong dugon, is listed as Vulnerable (VU A2bcd) with the IUCN Red List of Threatened Species:

VULNERABLE (VU)
A taxon is Vulnerable when the best available evidence indicates that it meets any of the criteria A to E for Vulnerable (see Section V), and it is therefore considered to be facing a high risk of extinction in the wild.

References & Further Research

BioOne ~ CITES ~ Discover Life ~ GBIF ~ Google Scholar ~ ITIS ~ IUCN RedList ~ MarineBio Network ~ NCBI ~ SCIRIS ~ SIRIS ~ Tree of Life Web Project ~ Wikipedia

Manatee & Dugong Research, Education, & Conservation
Mammal Species of the World
Rothauscher's Dugong site
Dugong dugon of Philippine Mammalian Fauna

Search the Web for Dugong » ARKive ~ Ask.com ~ Ask Jeeves ~ bing ~ deviantART ~ dmoz ~ Dogpile ~ Google Images ~ MySpace Images ~ OceanFootage ~ Picsearch ~ StumbleUpon ~ Yahoo! Images ~ YouTube

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Citation: Dugong dugon, Dugong - MarineBio.org. Retrieved , from .

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Dugong dugon Dugong [+]