Rising up on the Gulf Coast of Florida, manatees had been a part of our lives. We’d see them in marinas and on college discipline journeys. I bear in mind in the future close to the top of highschool, finding out for an examination in a solar lounger within the yard after I heard the whoosh of a manatee blowing because it surfaced. I appeared right down to see its whiskered snout just some ft away, sniffing like a canine’s does within the wind. She or he approached the seawall to get as shut as attainable, wanting straight at me earlier than ambling away towards our neighbors.
Just lately, on a stopover in Doha, Qatar, I noticed three totally different outside artwork installations depicting animals that appeared remarkably like manatees however with fluked tails like a whale or dolphin. I questioned,
“What’s swimming within the waters off Qatar and the way related are they to manatees off the Florida coast?”
Dugong
Dugongs of the Persian Gulf
The Persian Gulf is dwelling to the second-largest dugong inhabitants on the earth, which is basically targeting the southern coast between Doha and Abu Dhabi.
The dugong is certainly one of 4 residing species of the order Sirenia, which additionally contains manatees. It’s the solely residing consultant of the once-diverse household Dugongidae; its closest trendy 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 will 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 mild 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 trendy kin of sirenians are:
- elephants,
- aardvarks, and
- small mammals often called hyraxes.
These 4 orders of mammals are generally thought of subungulates, that 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 an alternative of claws.
West Indian and West African manatees have very fundamental fingernails on their forelimbs. Amazonian manatees and dugongs wouldn’t have any nails.
Dugong
Bodily Variations and Similarities between Dugongs and Manatees
At first look, manatees and dugongs might sound similar. Each are massive, aquatic mammals with rotund our bodies tailored for a sluggish grazing way of life. Listed here are some similarities and variations:
- Their eyes are related and their pores and skin is grey, however might 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 a different 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 can 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 kinds 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 after they breach for air and shut underwater.
- Maybe essentially 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
When it comes to dimension, dugongs are usually smaller than manatees. Manatees develop to be roughly 8 to 13 ft lengthy on common and weigh between 440 and 1,300 kilos. Dugongs, however, can attain 8 to 10 ft 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 dimension.
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 solely of seagrass. They use their higher lips to uproot the complete seagrass plant relatively 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 different food regimen, 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, however it’s believed to be declining, with a worldwide lower of 20% within the final 90 years.
Manatees, nevertheless, have seen a resurgence in recent times from very low numbers. In america, their inhabitants reached a low within the Seventies, with only some hundred people. As of 2016, 6,250 manatees had been reported swimming in Florida’s springs. The entire 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 replica, these species are particularly weak to extinction.
Dugongs are particularly weak attributable to their lengthy reproductive cycles. Feminine dugongs sometimes give start for the primary time at round 10 years of age and solely breed roughly each three to 6 years. Feminine manatees sometimes have their first child at age three and have extra infants each two to 3 years.
After a couple of 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 range in dimension from 2 to 200 people. Pairs of dugongs discovered collectively are sometimes mom and calf. There may be hardly ever sufficient seagrass to help massive teams over a very long time. Because of this, 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 more durable 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 jap coast of Africa
- within the Pink 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 way bigger globally, however attributable to their conduct, they could be tougher to identify.
Manatees, however, will be extraordinarily straightforward to identify and work together inside sure areas, particularly heat springs in and round Florida in the course of the winter months.
Florida shouldn’t be the one place to identify manatees within the wild. WWF is working in locations like Belize to guard seagrass beds and restore and shield key mangrove areas, and in Mexico by way of our Mangroves for Neighborhood and Local weather program. By defending coastal ecosystems, we’re additionally preserving worthwhile 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 grow to be domestically extinct. Divers and fishermen report common sightings in international locations as different 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 study extra about these mild giants, we will higher admire their position in our world’s various marine ecosystems.
