Whales, Dolphins, and Porpoises
Also known as cetaceans
Let's Learn About Whales, Dolphins, & Porpoises
Word of the Week
Baleen
Baleen is the hair-like structures that line the mouths of filter feeding whales like humpbacks and blue whales. It is made of keratin, like our nails and hair.
After taking in a mouthful of water and tiny organisms, they close their mouth and push the water out while the baleen traps the food inside.
Fast Facts
Where do whales, dolphins, and porpoises live?
Most cetaceans live in the ocean!
Whales, dolphins, and porpoises live in almost every part of the ocean. They can be found everywhere from tropical reefs to freezing arctic waters, with many species migrating between the two! Some species of dolphins can also be found in freshwater, like the Amazon river dolphin.
What do whales, dolphins, and porpoises eat?
Whales, dolphins, and porpoises are carnivores!
What they eat depends on the species. Toothed whales, like dolphins, porpoises, and orcas, feed on everything from fish to squid to penguins to seals. Baleen whales, like humpbacks, blue whales, and gray whales, feed on small organisms like krill, small fish, and other types of plankton.
What traits do cetaceans share?
Cetaceans are a large group of fully-aquatic mammals (meaning they never leave the water), so they share many traits for that environment!
- Cetaceans have lungs and breath using a blowhole (which is their nose!).
- Cetaceans push themselves through the water with a large tail fin that moves up and down.
- Cetaceans are often social and live in groups called pods.
- Cetaceans are quite vocal and use sound for communication.
How many whales and dolphins are there?
Scientists estimate there are roughly 90 species of cetaceans divided into two groups - the toothed whales and the baleen whales.
There are more than 4 times as many species of toothed whales as there are baleen whales! Toothed whales include all dolphins, all porpoises, and whales like sperm whales, belugas, narwhals, and pilot whales.
Baleen whales include the larger whales, like the blue whales, humpbacks, right whales, minkes, fin whales, bowheads, and more.
Species Spotlight
Sperm Whale
Physeter macrocephalus
Sperm whales, also known as cachalots, are not only the largest species of toothed whale, but the largest species of toothed predator! Measuring more than 50 feet in length, sperm whales are powerful predators that dive thousands of feet into the deep ocean to hunt. They feed on cephalopods like squid and octopus (often bearing scars from their deep sea battles), though they'll also feed on fish, stingrays, and some sharks. The can hold their breath for well over an hour on these dives! Because it is so challenging to learn about deep sea creatures, scientists have actually studied the stomach contents of sperm whales to learn about giant squid species!
Not only do sperm whales excel in hunting and diving, they are also quite impressive singers. Sperm whales are arguably the loudest animal in the world. They produce a clicking sound that reaches 233 decibels (this is louder than a jet engine at takeoff!) that travels several hundreds of miles through the water. Different families of whales communicate using different types of vocalizations, proving that the sounds they make are learned. Like other toothed whales, they also use their vocalizations during echolocation. This allows them to hunt and navigate in dark ocean waters!
BRAIN BLAST
Cetaceans sleep in the ocean, which makes them vulnerable to predators like sharks. Research how cetaceans avoid becoming prey while resting!
Conservation Corner
The Vaquita
Vaquitas are the smallest species of cetacean. Measuring up to 5 feet in length, this tiny porpoise is only found in the northern regions of the Gulf of California. Vaquitas are one the most endangered animals in the world with an estimated 10 individuals remaining in the wild. The main threat to vaquitas is the unsustainable fishing practice of local people for a prized fish called a totoaba. Long gillnets are placed in the water to entangle the the totoaba, but also entangle other marine animals, like sharks, turtles, and the vaquita.
The vaquita was first discovered in 1958 and conservationists have been working to protect it for decades. Because vaquitas are easily stressed, operations to capture vaquitas to start a breeding program have not been successful. With only 10 vaquitas remaining, it is unknown if we will be able to save this fascinating species, but there are things we can do to protect marine animals everyday. Reducing your plastic use and waste is a good place to start, and so is eating sustainable seafood.
Cetacean Classification
Determine which traits belong to toothed whales and which belong to baleen whales.
Cetacean Challenge
Learn More!
Glossary
Adaptation
The process by which a species becomes more fit for its environment over the course of several generations. It is a result of natural selection.
Aquatic
Living in water.
Baleen
The bristle-like structures that large, filter-feeding whales use to trap food.
Blowhole
The nostril of cetaceans located on top of their heads.
Camouflage
The ability for an organism to blend into their surroundings usually to hide from prey or predators.
Carnivore
An animal that eats other animals.
Cetacean
A clade of marine mammals that includes dolphins, whales, and porpoises.
Echolocation
The process of sending sound signals and determining the layout of the environment (including anything moving!) using the sound waves reflected back.
Ectotherm
An animal that relies on the outside temperature to regulate their body temperature (reptiles and amphibians). Also known as cold-blooded.
Endotherm
An animal that regulates their body temperature internally (mammals and birds). Also known as warm-blooded.
Herbivore
An animal that eats mostly plants.
Invertebrate
An animal that has no bones.
Keratin
A structural protein that makes up hair, nails, feathers, claws, and baleen.
Mammal
A group of endothermic (warm-blooded) vertebrates that are covered in hair, produce milk for offspring, and generally give birth to live offspring.
Marine Habitat
Various parts of the oceans categorized by the plants, animals, and non-living factors found there. Coral reefs, kelp forests, and the deep ocean are marine habitats.
Omnivore
An animal that eats both plants and animals.
Plankton
Microscopic organisms found floating in the ocean.
Predator
An animal that hunts other animals for food.
Prey
An animal that is hunted and eaten by another animal.
Species
A closely related group of animals with similar characteristics that are capable of reproducing (example: tigers).
Subspecies
A group of animals within a species that are genetically different from other groups in the same species (there are 6 subspecies of tigers).
Vertebrate
An animal that has a backbone.
