Rising up on the Gulf Coast of Florida, manatees have been a part of our lives. We’d see them in marinas and on college subject journeys. I bear in mind in the future close to the tip of highschool, finding out for an examination in a solar lounger within the yard once I heard the whoosh of a manatee blowing because it surfaced. I regarded right down to see its whiskered snout just some toes away, sniffing like a canine’s does within the wind. She or he approached the seawall to get as shut as doable, trying straight at me earlier than ambling away towards our neighbors.
Lately, on a stopover in Doha, Qatar, I noticed three totally different out of doors artwork installations depicting animals that regarded remarkably like manatees however with fluked tails like a whale or dolphin. I puzzled,
“What’s swimming within the waters off Qatar and the way comparable are they to manatees off the Florida coast?”
Dugong
Dugongs of the Persian Gulf
The Persian Gulf is residence to the second-largest dugong inhabitants on the earth, which is essentially targeting the southern coast between Doha and Abu Dhabi.
The dugong is one among 4 dwelling species of the order Sirenia, which additionally consists of manatees. It’s the solely dwelling consultant of the once-diverse household Dugongidae; its closest fashionable relative, the Steller’s sea cow, was found in 1741 and hunted to extinction by 1768. That species lived primarily within the Commander Islands of the western Bering Sea.
The present inhabitants of dugongs within the Persian Gulf is estimated to be between 5,000 and seven,000 people. Within the area, dugongs could be discovered within the territorial waters of Bahrain, Qatar, Saudi Arabia and the United Arab Emirates.
Dugong
Mammals of the order Sirenia
Their identify—Sirenia—comes from the Sirens of Greek mythology who lured sailors with their songs. These light giants of the ocean captivate us, although, with their serene demeanor. Regardless of their apparent similarities, manatees and dugongs are distinct species with distinctive traits and habits.
Research utilizing biochemical evaluation of proteins present that the closest fashionable relations of sirenians are:
- elephants,
- aardvarks, and
- small mammals often called hyraxes.
These 4 orders of mammals are generally thought-about subungulates, which means they could be evolutionary offshoots of a primitive ungulate (hoof) inventory. The anatomical traits they share embody the dearth of a collar bone and the presence of nails as a substitute of claws.
West Indian and West African manatees have very primary fingernails on their forelimbs. Amazonian manatees and dugongs would not have any nails.
Dugong
Bodily Variations and Similarities between Dugongs and Manatees
At first look, manatees and dugongs might sound an identical. Each are massive, aquatic mammals with rotund our bodies tailored for a sluggish grazing life-style. Listed here are some similarities and variations:
- Their eyes are comparable and their pores and skin is grey, however could seem brown or inexperienced as algae grows on them as a result of they transfer slowly.
- Neither dugongs nor manatees have dorsal fins. Their snouts are designed to feed on ocean grasses, however fairly in another way.
- Dugongs have brief, broad, downward-facing, trunk-ish snouts which might be horseshoe-shaped with a slit-like mouth. The snout ends with a cleft, a muscular lip that aids the dugong in its foraging for seagrass—as a result of it’s a strictly bottom-dwelling feeder.
- Manatees have shorter snouts, which implies that they’re able to collect meals and feed on vegetation rising at or close to the floor of the water.
- One other distinction is that manatees have solely six cervical vertebrae; all different mammal species besides two varieties of sloth have seven.
- A dugong’s nostrils are additional again on its head than they’re on a manatee. Each are specifically designed to be submerged in water. Dugongs’ nostrils act like valve openings on prime of their heads; they open once they breach for air and shut underwater.
- Maybe probably the most noticeable bodily distinction between dugongs and manatees is their tail form. Manatees have rounded, paddle-shaped tails, whereas dugongs have fluked tails.
Manatee
Look and Dimension of Manatees and Dugongs
By way of measurement, dugongs are typically smaller than manatees. Manatees develop to be roughly 8 to 13 toes lengthy on common and weigh between 440 and 1,300 kilos. Dugongs, then again, can attain 8 to 10 toes lengthy and weigh between 510 and 1,000 kilos.
Though dugongs can weigh greater than manatees, it’s uncommon for a dugong to achieve that measurement.
The smaller finish of the vary is typical for dugongs, which makes them seem slimmer and longer in comparison with manatees, as does their longer snout.
Manatee
Behavioral Variations between Manatees and Dugongs
Each dugongs and manatees are slow-moving creatures. Their feeding habits differ barely. Dugongs’ diets consist fully of seagrass. They use their higher lips to uproot your complete seagrass plant reasonably than consuming solely the leaves—this results in dugong trails like sandy paths by way of seagrass beds. They’ve very sluggish metabolic charges, and when seagrass is scarce, they may also eat algae.
Manatees have a way more assorted weight loss plan, consuming over 60 species of vegetation, together with sea clover, kelp, algae, turtle grass, manatee grass, shoal grass, mangrove leaves, varied algae, water hyacinth, acorns and hydrilla.
Manatee mom and calf
Inhabitants and Conservation of Manatees and Dugongs
The dugong inhabitants is estimated to be round 100,000, nevertheless it’s believed to be declining, with a worldwide lower of 20% within the final 90 years.
Manatees, nonetheless, have seen a resurgence lately from very low numbers. In the US, their inhabitants reached a low within the Seventies, with just a few hundred people. As of 2016, 6,250 manatees have been reported swimming in Florida’s springs. The full inhabitants of manatees is estimated at greater than 13,000.
The Worldwide Union for Conservation of Nature (IUCN) lists each manatees and dugongs as weak species. Their populations face threats from habitat destruction, searching, and fishing-related fatalities. With their lengthy lifespans of round 70 years and sluggish charges of copy, these species are particularly weak to extinction.
Dugongs are particularly weak attributable to their lengthy reproductive cycles. Feminine dugongs usually give start for the primary time at round 10 years of age and solely breed roughly each three to 6 years. Feminine manatees usually have their first child at age three and have extra infants each two to 3 years.
After a few year-long being pregnant (as much as 14 months for dugongs), each feminine manatees and dugongs start calves that stick with them for round two years.
Dugongs are a social species present in teams that may fluctuate in measurement from 2 to 200 people. Pairs of dugongs discovered collectively are sometimes mom and calf. There’s hardly ever sufficient seagrass to help massive teams over a very long time. In consequence, dugongs are semi-nomadic; some will migrate lengthy distances whereas others keep in the identical space for all times. Their journey is pushed by the provision of seagrass.
Dugongs are identified for being extra cautious of people and tougher to identify since they’re backside feeders. Manatees, although, fairly often work together with people and reside in populated areas.
Manatees
Vary, Habitat and Distribution of Dugongs and Manatees
Each manatees and dugongs are present in heat tropical or subtropical waters, however their habitats don’t overlap.
The dugong’s vary is within the heat coastal waters of the Indian and Pacific oceans from East Africa to Australia. The most important dugong populations are within the following:
- Western and northern Australia’s Shark Bay and Moreton Bay
- On the western coast of Madagascar and alongside the coast of Mozambique
- Alongside the japanese coast of Africa
- within the Crimson Sea
- the Persian Gulf
- across the Indian subcontinent, and
- by way of the western Pacific Ocean.
Manatees
Subspecies of manatees inhabit:
- West Indian manatees (Florida & Antillean) are present in coastal areas of the Caribbean, the Gulf of Mexico, and the Amazon River from Florida to Brazil.
- Amazon manatees are discovered within the Brazilian Amazon Basin.
- West African manatees are discovered on the western coast of Africa from Mauritania within the north to Angola.
Each dugongs and manatees migrate as they graze, fragmenting the inhabitants into small teams all through these areas.
In contrast to dugongs, which keep in saltwater, manatees can reside in contemporary, salt, or brackish waters and like—even want—to drink contemporary water.
Dugong
The place to Spot Dugong and Manatees
Dugongs’ vary is far bigger globally, however attributable to their habits, they could be harder to identify.
Manatees, then again, could be extraordinarily simple to identify and work together inside sure areas, particularly heat springs in and round Florida through the winter months.
Florida isn’t the one place to identify manatees within the wild. WWF is working in locations like Belize to guard seagrass beds and restore and defend key mangrove areas, and in Mexico by way of our Mangroves for Group and Local weather program. By defending coastal ecosystems, we’re additionally preserving beneficial habitat for manatees.
Many of the world’s dugong inhabitants now happens in northern Australian waters between Shark Bay in Western Australia and Moreton Bay.
Within the Philippines, dugong populations are fragmented, and in Taiwan and China, they’ve change into domestically extinct. Divers and fishermen report common sightings in international locations as assorted as Borneo, Egypt, Vanuatu, and Sri Lanka.
Manatees and dugongs share many similarities however are distinct with distinctive traits and habits. Understanding these variations is essential for his or her conservation and our continued enjoyment and safety of those fascinating mammals. As we proceed to be taught extra about these light giants, we are able to higher admire their position in our world’s numerous marine ecosystems.