November brings with it Manatee Awareness Month.
And at any mention of Manatees, Dugongs are a close second thought. Which makes us realise that there’s still little awareness on the differences between Manatees and Dugongs. While they look very similar; slow, big and gentle sea cows, grazing the sea bed. They are in fact two different species.
So for Manatee Awareness Month, we hope shed some light on what’s what and what’s not.
Grey, two flippers and a tail! One reason why they may look so similar, is because they are cousins. They may not be from the same species or even family, but they are from the same scientific order Sirenia. There are four living species of Sirenia – the West Indian manatee, the Amazonian manatee, the West African manatee and the dugong – and they are all referred to as “sea cows”.
To tell the two apart, we’ll go into three categories;
1) The obvious physical aspects, 2) Behaviours and 3) Habitat.
Physical: Tails & Mouth
One of the clearest differences between the two are their tails! Manatees have a horizontal, paddle shaped tail with only one lobe to move up and down, similar to a beaver’s tail. Dugongs have a fluke tail, two separate lobes joined together in the middle, much like a dolphin or whale’s tail.
Despite their tail, Manatees and Dugongs are not closely related to beavers, whales or dolphins, but elephants!
Looking at their faces, Manatees have a divided upper lip and a shorter snout, enabling to also feed on plants growing at or near the surface of the water, instead of relying on just the sea bed.
Dugongs have short, broad, downward facing snouts with a slit-like mouth. The snout ends with a cleft, a muscular lip that helps the dugong forage for seagrass – because of this it is a strictly bottom-dwelling feeder.
Another obvious physical difference is the presence of tusk-like incisors in mature male dugongs, while there are none in manatees.
Behaviour: Partners & Birth Rate
Both are solitary creatures, with the manatee being the slightly more sociable cousin than the other. When it comes to romantic advances, the manatee is a polygamist with several female partners and plenty of love to go a round. While the dugong marries his childhood sweet heart, sticking to just one mate for the rest of its life.
When it comes to offspring, both manatees and dugongs are mammals, thus giving birth to live young. Female manatees usually give birth at three years old and continue to do so every two to three years. While female dugongs are much late bloomers, giving birth at ten years old and only every three to five years after that.
However, Dugongs do have a much longer live span of 70 years as compared to that of the Manatees at 40 years. So if we re-arrange the math taking into count their longer life span, they aren’t late bloomers after all.
Dugongs are strictly marine mammals, while Manatees generally live in fresh water.
Image Source 1: http://animaldiversity.org