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Sea cows are not the prettiest marine mammals, and these strange looking herbivores are not the most abundant creatures on earth.
Nonetheless, this guide explains the common behavioural traits and characteristics of the dugong vs. manatee and how to differentiate the species.
In fact, they are both related and they have several things in common:
The dugong and the manatee are both species of marine mammals falling under the Order Sirenian. But, there are only four extant (surviving) species:
Pro Tip: 'Stella's sea cow' was a tropical sea cow that inhabited the Commander Islands in the Bering Sea. It was hunted to extinction during the 18th Century, mainly for a source of food.
So, even though they share some relationship in a taxonomic sense, it's fair to say the two families live in different regions around the world. For example, the best place to find dugongs includes:
Whereas, to catch sightings of manatees you should head out to the Amazon Basin, the Caribbean, or select areas in the Gulf of Mexico.
Thus, the global distribution of dugongs and manatees could not be more different. Likewise, the habitats that they occupy is another factor that separates the two species.
For example:
Dugongs spend their entire life in a saltwater environment. Whereas, you can find manatees thriving in salt water as well as some bodies of fresh water. Even so, both species prefer the nutrient rich food sources found at coastal regions.
Pro Tip: Are you heading to the famous dive sites of North Sulawesi, Indonesia? If so, you should see dugongs at the mangroves of Manado and around Bangka Island (located in the Bunaken National Marine Park).
In fact, manatees and dugongs feed on seagrasses (flowering plants growing in marine environments). Thus, both species forage for food on the sea bed in areas where land masses meet water.
For the most part, dugongs are typical herbivores. Even so, they will also eat small sized marine mollusks, such as octopus and squid (decapodiformes).
By comparison, it's common to see manatees feeding on small fish species - especially in areas where sea grass is in limited supply.
A size comparison is one of the easiest ways to differentiate dugongs and manatees. By and large, a manatee will grow to be a lot longer, wider (breadth), and heavier than a dugong.
The average length of an adult dugong is about three (3) metres (around 10 feet) when measured from its snout to its tail and they can weigh up to 270 kilograms (595 pounds).
The average length of an adult manatee is more than three metres (up to 13 feet) when measured from its snout to its tail and the heaviest specimens can weigh up to a colossal 1,588 kilograms (3,500 pounds).
Fun Fact: There is a sizable difference in weight between the males and females. In general, the females of both species will weigh heavier than the male counterparts.
All Sirenia (the taxonomic reference used for sea cows) share the distinguishing characteristic of a projecting nose - called the snout. But, the size and shape of snouts in dugongs and manatees varies.
The snout of a manatee is shorter than a dugong and somewhat 'squashed' in its appearance. Plus, manatees are one of the few true aquatic mammals that have prehensile lips (able to grasp objects) and they use their two fore limb flippers for digging up the roots of seagrass.
Whereas, the dugong's snout is broader and resembles the shape of a trunk (e.g. used for the efficient feeding of seagrass that grows on the sea bed).
It's easy to spot the tail of a dugong because it is 'fluked' (like dolphins). By comparison, manatee tails are more rounded and paddle-shaped (similar to beavers).
Here's the thing:
The shape of the tail affects the way dugongs and manatees move through water. Hence, dugongs tend to propel themselves through powerful fin action (up and down motions). Whereas, manatees have limited movement from their tail, making them less agile and a little slower.
For the most part, dugongs stay with one mate throughout their entire lifetime. In other words, it's a monogamous mammal. Even so, it will try to find a new mate if the lifelong partner dies.
Conversely, manatees are the exact opposite. In fact, it's not uncommon for a polygamous male manatee to have several female mates all at the same time.
Female dugongs usually need to be at least ten (10) years of age before they can reach sexual maturity. However, female manatees tend to reach maturity at a much younger age, around three (3) years old.
Pro Tip: The main section contains a list of some good examples of aquatic mammals - defined as an animal that relies on some kind of marine ecosystem for its survival.
Note: The short video [55 seconds] presented by 'Murex Resort' shows scuba divers getting very close to the dugong while observing it in its natural habitat.