Species of the week

This week Biodinâmica gives you the Dugong, the “mermaid” species.

Scientific name: Dugong dugon
Class: Mammalia
Order: Sirenia
Family: Dugondidae
Diet: are primary consumers, they feed primarily seagrass and algae
Average life time: 55 to 70 years
Size: can reach up to 3 meters long
Weight: 500kg or more
Status: Vulnerable

The Dugongo also called Dugong is one of the few species of Sirenia order that still lives today. The dugong name comes from Duyung Malay word which means mermaid. They have a thick skin, grayish tone, the body is cylindrical and elongated.

Social organization: small groups of 2 or 4, but some solitary individuals may be found.

Reproduction: Dugongs reach sexual maturity between 8-15 years and they have a period of 12 months gestation, reproducing throughout the year, but births are more frequent between July and September. Every 5 years dugongs have offspring, and they are fed on milk between 14 and 18 months.


Ecology: like other marine mammals, dugongs comes to the surface to breathe, and have an average break between breaths 2-3 minutes. They need about 30 kg of food per day, they feed primarily on seagrass, and only when these are scarce, they feed on algae (some individuals in Australia feed on some invertebrates).
They live in coastal areas, not in very deep waters. They may sometimes penetrate the estuaries of some rivers, without distancing from the oceans.

Distribution: It lived once in all tropical regions of the Indian and Pacific Oceans, but nowadays their distribution are more limited. The main populations live in the Great Barrier Reef in Australia and in the Torres Strict. In Mozambique, significantly larger populations are found in the south, in the Bazaruto Archipelago National Park, a marine conservation area.

Threats: bycatch during fishing, boat strikes and boating activities, modification / habitat loss by anthropogenic actions, threats seagrass, chemical pollution, climate change, low fertility rate.


Conservation measures: reducing the impacts of anthropogenic activities; protection initiatives that should cover not only occurrence sites as well as areas where they usually migrate; protection of their habitat.

Curiosities: It is believed that it has been Dugong who originated the legend of the mermaid, a being half fish, half woman. In fact, the Dugong is far from possessing the beauty of the legendary mermaids, but it has two similar characteristics of women: breast and how female holds its baby while breastfeeding.