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Sirenia. Cetaceans Toothed Whales Baleen Whales Dolphins Porpoises Sirenia Manatee Dugong Steller’s Sea Cow. Pinnipeds True Seals Fur Seals Sea Lions Walrus Mustelidae Sea Otters River Otters Polar Bears Ursus Maritimus. Marine Mammals.
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Cetaceans Toothed Whales Baleen Whales Dolphins Porpoises Sirenia Manatee Dugong Steller’s Sea Cow Pinnipeds True Seals Fur Seals Sea Lions Walrus Mustelidae Sea Otters River Otters Polar Bears Ursus Maritimus Marine Mammals
General Facts • They spend their entire life in water. • Sirenia are vegetarians eating up to 150 lbs a day. They eat turtle grass, water lettuce and water hyacinth. • They live in tropical waters above 70 degrees. • The Sirenia hind limb is called a paddle. • Their mammary teats are in their armpits. • Sirenia have whiskers called Vibrisae ( sensory) • To detect food on the bottom.
Life Status • The Dugong is classified as Vulnerable from Africa to Australia. • The Manatee is Endangered especially the Amazonian manatee. • The Stellar Sea Cow of the Arctic was extinct within 27 years.
Sirens of the Sea Sirenia This group of Sea Mammals is probably responsible for most of the stories and fantasies about Mermaids. Today the inspiration for these magical creatures are in danger of becoming extinct.
Manatees Sirenians Trichechus manatus (Florida manatee) Dugong Dugong dugon (Dugong)
Manatee Whiskers • Vibrisae • “vibrisae” or whiskers on a • manatee’s snout are sensory • in function. • Each whisker has a • nerve connection to a small • cluster of cells in the • manatee’s brain devoted • exclusively to that whisker!
Sea Cows • Manatees and Dugong • are known as “Sea Cows” • because they are the only • vegetarian marine • mammals
Manatee Diet • The Manatee feeds off the bottom, in the water column, and at the surface.
Blow Holes • Nostrils • They breathe through nostrils, like seals. • Their nostrils have fleshy "valves" that close when they are underwater
Sirenia Distribution • Manatees and Dugongs range throughout the shallow tropical waters of the world. They live in waters above 70 degrees F. Only the extinct Steller’s Sea Cow could tolerate the colder waters of the North Pacific.
Sirenian Distribution • This distribution map includes the extinct Steller’s sea cow. Steller’s sea cow bones have been found as far south as Japan and along the California Coast.
Amazonian Manatee The smallest of the manatees. 6 feet long with an average weight of 650 to 800 pounds The Amazonian Manatee is the only manatee that lives solely in fresh water three to six feet deep, but can dive to depths of 20 feet. These gentle mammals are found throughout the entire Amazon basin including lakes, rivers and tributaries.
AmazonianManatee • Diet Floating grass Meadow Giant Water Lily These fresh water manatees eat about 10% to 15% of their body weight in water plants daily.
Amazonian Manatee • Status • The Amazonian Manatee, along most other manatee species face extinction. They are easy prey for hunters in search of meat, hides and oil. Dozens of manatees are injured and killed each year by propellers.
Florida Manatee (West Indian) • Description • The skin is wrinkled and is scattered with small almost colorless hairs. • An average adult grows to be about 10 feet long and weighs in at about 1,000 pounds. • The manatee has flippers similar to the seal and walrus, and a wide flattened tail.
Florida Manatee (West Indian) They “Gum” their food • The roof of the Manatees mouth (front section) have horny ridged pads. • The molars (their only teeth) located at the back of the mouth finish the chewing process.
Florida Manatee (West Indian) • Habitat • Manatees can usually be found in shallow coastal waters, slow moving rivers, estuaries, saltwater bays, canals and coastal areas that are rich in sea grass and other vegetation. • They have small beady eyes that are sunken on either side of their face.
Florida Manatee (West Indian) Florida manatees range • Distribution • Florida manatees range from the mouth of the Chesapeake bay to Texas in the Gulf of Mexico. • They mostly inhabit the shallow waters of Florida
Dugong • Dugongs are herbivores just like Manatees . • Dugongs require 66 pounds of sea grasses and algae per day. • The dugong is classified as • vulnerable by the IUCN (1996). • Numbers are declining fast • world-wide because they are • caught in fishing nets, and sea grass beds disappear as water becomes muddy.
Dugong • Length Weight: • 8-13 ft 500-1980 lb • . • Unlike the manatees, the tail of the dugong is "fluked", resembling that of whales and dolphins.
Dugong • Distribution
Dugong • Young animals hitch rides on their mothers backs, surfacing and submerging in enforced unison. • Although the drinking of milk may continue for a year and a half, young dugongs begin sampling sea grasses at about three months of age. • Females generally give birth once every 3-7 years.
Steller’s Sea Cow Hydrodamalis gigas
Steller’s Sea Cow (Extinct) • Far larger than the largest male walrus. • Hydrodamalis feed on parts of algae and sea grass • Steller's sea cows measured up to 25 feet long and 22 feet around. • A single animal weighed up to 8,800 pounds.
Steller’s Sea Cow (Extinct) • Habitat • Hydrodamalis is known to have occurred in cold, shallow, coastal marine waters rich in algae and sea grass. • Hydrodamalis was gregarious, • Hydrodamalis appears to have been monogamous, and the animal's behavior suggests the pair bond was quite strong. • Its range was restricted to islands in the Bering Sea during historic times, but extended to California and Japan during prehistoric times.
Steller’s Sea Cow (Extinct) • Distribution at time of extinction
Steller’s Sea Cow (Extinct) • The Steller’s sea cow which roamed the Arctic Oceans for thousands of years was destroyed by man in just 27 years after their discovery. • It is not known exactly when the last individual of Hydrodamalis died, but it appears likely that the species was extinct by 1768.
Sirens of the Sea • Dugongs Endangered • Dugongs are listed as "vulnerable" and are being depleted over their whole range from Africa to Australia. • The largest existing groups are along the coast of north-west Australia where there is an aggressive protection program.
Sirens of the Sea • Manatees Nearing Extinction • The Manatee’s plight appear to be even more critical than the dugong. • The African species, along the west coast from Senegal to Angola, is "seriously depleted throughout its range". It is still being hunted for it’s meat.
The End By Richard Butler for the Virginia Aquarium
