Cetaceans - Marine Biology
What are Cetaceans?
Includes species of whales, dolphins, and porpoises
Cetaceans are white, black, gray, bluish-gray, or pink in color, many are spotted, mottled, streaked, or boldly patterned
Key characteristics:
Fully aquatic lifestyle
Streamlined body shape
Often large size
Exclusively carnivorous diet
Tetrapods
Cetacea are predominantly adapted to marine life, cannot survive on land at all
Evolved from four legged animals (tetrapods), for which limbs played a primary role in movements, into virtually limbless aquatic creatures living in an environment where the back muscles are more important
Where can cetaceans be found?
In almost the entire ocean as a whole, though there are some species that only appear in locally or broken populations
Habitats include all oceans, arctics, and brackish water (salt/freshwater but mostly salt)
Can live in just about any climate for there are species that are able to live in water that is near-freezing temperatures
Key Adaptations
Rather than in a horizontal plane, they use vertical strokes when they swim instead of horizontal like a crocodile or fish (locomotive system)
It is made up of the skeleton, skeletal muscle, ligaments, tendons, joints, cartilage, and other connective tissues. It makes sure that these parts work together to allow their body to move
Their adaptations can be seen through characteristics such as:
Dorsal blowhole: allows animals to breathe
Baleen teeth: allows animals to "filter feeds
Cranial "melon" organ:Ā organ for aquatic echolocation
Body Systems
Locomotive system, which they use to swim, one of the most important body systems
Because of their descendants from mammals, they now swim using vertical strokes instead of horizontal
Cetaceans are relatively known for their extremely efficient lungs and circulatory system, which allows them to dive for extended periods of time, allowing them to use about 12% of the oxygen they inhale compared to 4% used by terrestrial mammals
Cetaceansā flippers and flukes have a countercurrent heat exchange system, wherein heat from arterial blood warms venous blood as it returns to the heart. Both small and large cetaceans are insulated by their thick blubber layer
Key Orders
Cetaceans provide a greater understanding of brain functioning in intelligent/social animals
Already helped us understand so much about the brain function, learning, culture, and communication within the animal kingdom, including ourselves
Ceteaceanās keystone species is the blue whale
Blue whales help to keep the number of krill and phytoplankton in balance
This is key to the functioning of their aquatic ecosystem because phytoplankton are the core of the food pyramid
They are indicator species in the marine environment-- they are used to monitor changes in our environment
What Phylum do Cetaceans Belong To?
Belongs to Phylum Chordata
Made up of animals w/ vertebrates or a spinal column and a cranium
Also known as āChordatesā
All have bilateral symmetry
All at one point have had a notochord, dorsal nerve chord, and gill slits
Belongs to Class Mammalia
What Makes Them Unique?
Cetaceans known for breathing through the blowhole on top of their head
Although they live completely underwater, cetaceans use their blowhole to inhale/exhale oxygen, much like humans use nostrils
They are mammals. They breathe air, have hair, are warm-blooded, give birth to their live young, and feed their babies milk
What are Cetaceans?
Includes species of whales, dolphins, and porpoises
Cetaceans are white, black, gray, bluish-gray, or pink in color, many are spotted, mottled, streaked, or boldly patterned
Key characteristics:
Fully aquatic lifestyle
Streamlined body shape
Often large size
Exclusively carnivorous diet
Tetrapods
Cetacea are predominantly adapted to marine life, cannot survive on land at all
Evolved from four legged animals (tetrapods), for which limbs played a primary role in movements, into virtually limbless aquatic creatures living in an environment where the back muscles are more important
Where can cetaceans be found?
In almost the entire ocean as a whole, though there are some species that only appear in locally or broken populations
Habitats include all oceans, arctics, and brackish water (salt/freshwater but mostly salt)
Can live in just about any climate for there are species that are able to live in water that is near-freezing temperatures
Key Adaptations
Rather than in a horizontal plane, they use vertical strokes when they swim instead of horizontal like a crocodile or fish (locomotive system)
It is made up of the skeleton, skeletal muscle, ligaments, tendons, joints, cartilage, and other connective tissues. It makes sure that these parts work together to allow their body to move
Their adaptations can be seen through characteristics such as:
Dorsal blowhole: allows animals to breathe
Baleen teeth: allows animals to "filter feeds
Cranial "melon" organ:Ā organ for aquatic echolocation
Body Systems
Locomotive system, which they use to swim, one of the most important body systems
Because of their descendants from mammals, they now swim using vertical strokes instead of horizontal
Cetaceans are relatively known for their extremely efficient lungs and circulatory system, which allows them to dive for extended periods of time, allowing them to use about 12% of the oxygen they inhale compared to 4% used by terrestrial mammals
Cetaceansā flippers and flukes have a countercurrent heat exchange system, wherein heat from arterial blood warms venous blood as it returns to the heart. Both small and large cetaceans are insulated by their thick blubber layer
Key Orders
Cetaceans provide a greater understanding of brain functioning in intelligent/social animals
Already helped us understand so much about the brain function, learning, culture, and communication within the animal kingdom, including ourselves
Ceteaceanās keystone species is the blue whale
Blue whales help to keep the number of krill and phytoplankton in balance
This is key to the functioning of their aquatic ecosystem because phytoplankton are the core of the food pyramid
They are indicator species in the marine environment-- they are used to monitor changes in our environment
What Phylum do Cetaceans Belong To?
Belongs to Phylum Chordata
Made up of animals w/ vertebrates or a spinal column and a cranium
Also known as āChordatesā
All have bilateral symmetry
All at one point have had a notochord, dorsal nerve chord, and gill slits
Belongs to Class Mammalia
What Makes Them Unique?
Cetaceans known for breathing through the blowhole on top of their head
Although they live completely underwater, cetaceans use their blowhole to inhale/exhale oxygen, much like humans use nostrils
They are mammals. They breathe air, have hair, are warm-blooded, give birth to their live young, and feed their babies milk