Modern marine mammals include: Cetacea (whales, dolphins, and porpoises), Sirenia (sea cows and dugongs) and Pinnipedia (seals, sea lions, and walruses). Pinnipeds are semi-aquatic and all pinnipeds retain hind limbs. In pinnipeds, both the fore and hindlimbs are modified into flippers.
What are the 4 types of pinnipeds?
The pinnipeds are a group of 33 species of aquatic fin-footed mammals composing three families: the true seals (family Phocidae), the fur seals and sea lions (family Otariidae), and the walrus (family Odobenidae).
What are the 5 groups of marine animals?
There are five groups of marine mammals: pinnipeds (or “flipper-footed” animals like seals, sea lions, fur seals and walruses), cetaceans (species that cannot survive on land, such as whales, dolphins and porpoises), sea otters (the smallest marine mammal), sirenians (warm water species such as dugongs and manatees) …
What is the difference between cetaceans and sirenians?
Cetacea and sirenia are two taxonomic orders of aquatic mammals. Cetaceans are large carnivorous aquatic mammals, while sirenians are small herbivorous aquatic mammals.
What are the three families of pinnipeds?
Pinnipeds are separated into three groups: earless seals, eared seals and walruses. Sometimes referred to as earless seals or true seals, marine mammals in the phocid family can be easily identified by looking at their ears and flippers.
Is an otter a cetacean?
There are four main groups of marine mammals: Cetaceans (whales, dolphins, and porpoises), sirenians (manatees and dugong), pinnipeds (earless seals, eared seals, and walruses), and several otters (the sea otter and marine otter). …
What are the 3 families of pinnipeds?
How many species of pinnipeds are there?
33 species
There are 33 species of pinnipeds alive today, most of which are known as seals.
What makes a cetacean a cetacean?
A cetacean is a member of the family of large aquatic mammals such as whales, dolphins, and porpoises. They have tails rather than hind limbs, and they have flippers instead of forearms. any of several whales having simple conical teeth and feeding on fish etc.
What are cetaceans physical characteristics?
Order Cetacea
- Fusiform-shaped body.
- Large body size.
- Virtually hairless.
- Blubber.
- No sebaceous glands.
- Tails flattened dorso-ventrally into flukes.
- Forelimbs are modified into flippers.
- Vestigial hindlimbs.
Are absent in cetacean and Sirenia?
1. Absent, except a few bristles around the muzzle which may also be absent in many whales. …
What are the characteristics of a pinnipeds?
Pinnipeds have four webbed flippers used to propel their spindle-shaped bodies. Their sensory organs are adapted to function in both air and water: large eyes and well-developed whiskers allow feeding in dimly lit water; tail and external ears are small, limiting drag.
Is a pinnipede a herbivore?
Pinnipeds spend the majority of their lives swimming and eating in water and come onto land or ice floes to bear their young, rest, and molt. Like cetaceans, sirenians also spend their whole lives in water. They are the only entirely herbivorous group of marine mammals.
How many types of cetaceans are there?
There are over 70 different species of cetacean. are in the suborder pinnipedia, which means “fin-footed.” These carnivores use flippers to move both on land and in the water. Pinnipeds spend the majority of their lives swimming and eating in water and come onto land or ice floes to bear their young, rest, and molt.
How do pinnipeds move?
These carnivores use flippers to move both on land and in the water. Pinnipeds spend the majority of their lives swimming and eating in water and come onto land or ice floes to bear their young, rest, and molt. Like cetaceans, sirenians also spend their whole lives in water. They are the only entirely herbivorous group of marine mammals.
Is a sirenian a cetacean?
Like cetaceans, sirenians also spend their whole lives in water. They are the only entirely herbivorous group of marine mammals. Sirenians are named for sirens, the legendary Greek sea beauties who lured sailors into the sea.
