Dugong dugon (Dugong, Sea cow, Sea pig)

dugong [Afrikaans]

Life > Eukaryotes > Opisthokonta > Metazoa (animals) > Bilateria > Deuterostomia > Chordata > Craniata > Vertebrata (vertebrates)  > Gnathostomata (jawed vertebrates) > Teleostomi (teleost fish) > Osteichthyes (bony fish) > Class: Sarcopterygii (lobe-finned fish) > Stegocephalia (terrestrial vertebrates) > Reptiliomorpha > Amniota > Synapsida (mammal-like reptiles) > Therapsida > Theriodontia >  Cynodontia > Mammalia (mammals) > Placentalia (placental mammals) > Afrotheria > Paenungulata > Tethytheria

Dugongs are entirely aquatic and never come onto land. Thought to have been mistaken for mermaids by mariners, they have large cigar-shaped bodies with paddle like foreflippers. The hindlimbs have been lost, leaving only a vestigial pelvis. The tail has large fleshy tail flukes like those of a dolphin. They have sparse bristles scattered over their grayish-brown skin. The large fleshy snout has valved nostrils on the top and is covered with short, thick bristles. The snout and tusk-like incisors are used to root-up aquatic plants.

Rarely seen they occur singly, in pairs or small family groups although occasionally larger family parties of up to 30 animals are found. They are slow swimmers and expend very little energy.

Unlike most mammals there is no replacement of milk teeth. During their lifetime there is total of six pairs of cheekteeth in both jaws. Worn teeth are shed at the front and replaced at the back throughout their lives. This process is repeated until only two pairs of teeth remain in each jaw in old animals. They share this adaptation where the cheekteeth erupt in a continuous series with hyraxes and elephants with whom they are thought to have a common ancestry.

Distribution

Along Africa’s east coast, the southern limit is northern coast of KwaZulu Natal.

Habitat

Aquatic, shallow sheltered coastal waters in tropical areas.

Size

Body Length 2.5-4 m; weight range 350 - 900 kg

Gestation

13-14 months

Life span

60 years

Food

Predominantly sea-grass and some algae in shallow bays and lagoons.

Dental Formula

I C P

Threats

Dugongs are actively hunted by humans as a source of meat. Their numbers have reduced dramatically in their range and their conservation status is regarded as vulnerable.