1. The manatee and dugong, commonly known as sea cows, belong to the mammalian order Sirenia. The name Sirenia originates from the confusion early sailors had between mermaids and manatees.

2. The dugong is strictly marine, while West Indian and West African manatees can be found in both fresh and salt water. The Amazonian manatee lives only in fresh water.

3. The manatee has a rounded, paddle-shaped tail; the dugong has a dolphin-like tail. The elephant is their closest living relative.

4. Steller’s sea cow was a 25-foot-long sirenian that ate shallow-water sea kelp around Bering Island of the north Pacific. Hydrodamalis gigas — whose closest living relatives are the manatee and dugong — was discovered in 1741 and hunted to extinction by 1768.

5. There are three living species of manatee: the Amazonian, West African and West Indian. There are two subspecies of West Indian manatee: the Florida and Antillean species.

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6. The manatee can reach about 50 years of age. A captive female gave birth into her mid-40s. A newborn manatee needs to be helped to the surface by its mother in order to take its first breath.

7. A fourth species of “dwarf” manatee was observed in a small area of the Amazon basin in the 2000s, but whether it is simply a juvenile Amazonian manatee is a point of contention among scientists.

8. A single calf, rarely twins, is born after a gestation of 11 to 14 months and remains with its mother for another 18 to 24 months.

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9. All species of manatee and the dugong are considered vulnerable to extinction or worse by the IUCN World Conservation Union.

10. The manatee and dugong use facial hair to manipulate and ingest aquatic vegetation. Sirenians are the only vegetarian marine mammals.

11. Dugongs have been found to travel up to 390 miles and can dive to 120 feet, sometimes crossing deep ocean trenches to reach remote islands.

12. The Amazonian manatee is the smallest of the group, measuring up to 9 feet and weighing less than 1,000 pounds.

13. Latest estimates put the global population of the Florida manatee at 6,350 individuals; this is fewer than the number of worldwide human births happening every 30 minutes. Threats to manatees include watercraft collisions and habitat loss.

Follow Richard Smith’s under water adventures at oceanrealmimages.com.

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