Characteristics of sirenia
What are the two main groups of Sirenia?
The Sirenia currently comprise two distinct families: Dugongidae (the dugong and the now extinct Steller’s sea cow) and Trichechidae (manatees, namely the Amazonian manatee, West Indian manatee, and West African manatee) with a total of four species.
How many species are there in Sirenia?
There are only five living species of sirenians, known collectively as “sea-cows,” including the dugong and the manatees.
What does the word Sirenia mean?
sirenian • \sye-REE-nee-un\ • noun. : any of an order (Sirenia) of aquatic herbivorous mammals (as a manatee, dugong, or Steller’s sea cow) that have large forelimbs resembling paddles, no hind limbs, and a flattened tail resembling a fin.
What are Sirenia related to?
Sirenia are the order of placental mammals comprising modern seacows and their extinct relatives. They are the only herbivorous marine mammals now living, and the only herbivorous mammals ever to have become totally aquatic. Sirenians have a known fossil record extending over some 50 million years.
How did order Sirenia get its name?
The order Sirenia was named after the Sirens of Greek mythology, and sirenians are believed to be the basis for the mermaid myth. Modern sirenians have two front limbs in the form of flippers but no hind limbs; even the pelvis is vestigial, and there are no skeletal remnants of leg or foot bones at all.
What is the order of Sirenia?
Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives.
What is Cetacea and Sirenia?
Cetacea is an infraorder comprising of large carnivorous aquatic mammals, while sirenia is an order comprising of small herbivorous aquatic mammals. So, this is the key difference between cetacea and sirenia.
What animal is called a sea cow?
Manatees look a bit like walruses or chunky porpoises and are sometimes referred to as sea cows, but they’re actually much more closely related to elephants.
Do sirenians have hair?
Sirenians have the following morphological characteristics in common: robust body; tough, thick skin with little hair; two nostrils on top or at the front of a thick muzzle; no ear pinnae; no hind limbs; mammary nipples located near the axillae; forelimbs modified into flippers; a horizontally flattened tail; and dense …
What animal is called a sea cow?
Manatees look a bit like walruses or chunky porpoises and are sometimes referred to as sea cows, but they’re actually much more closely related to elephants.
How many dugongs are left?
around 30,000 dugongs
How many dugongs are left in the world? There are believed to be around 30,000 dugongs left in the world. The largest populations are in the waters around Australia.
What is absent in Cetacea Sirenia?
Hairs: Absent, except a few bristles around the muzzle which may also be absent in many whales.
What is Cetacea and Sirenia?
Cetacea is an infraorder comprising of large carnivorous aquatic mammals, while sirenia is an order comprising of small herbivorous aquatic mammals. So, this is the key difference between cetacea and sirenia.
Do dugongs cry?
Although the tears of the dugong suggest a tale of sorrow, they also offer us a way to reflect on the wider currents of human-ocean interactions and to imagine new understandings of society’s past and nature’s present. Featured Image: Dugong, 2017. Source: Wikimedia Commons.
What animal is the queen of the sea?
Marine biologists have discovered an enormous great white shark they’re calling the “queen of the ocean” off the coast of Nova Scotia. The battle-scarred shark (Carcharodon carcharias) is 17 feet (5 meters) long and weighs in at 3,541 pounds (1,606 kilograms).