general
whales are all mammals and have structures that distinguish them from other marine mammals, like the blowhole from where they breathe, tail fin or fluke, dorsal fin, ventral fins for aquatic movement, baleen for feeding, spermaceti for communication and a general shape which is similar to fish.
whales aren't fish, though, whales have lungs, body hair, can milk and give birth, features mammals are known for having, but fish usually don't have.
it is believed that all cetaceans have a common ancestor called pakicetus, a land mammal living in modern pakistan that started to step into the water to obtain food. pakicetus slowly evolved into a marine mammal, then diverged into the different current day whales.
the easiest classification within cetaceans is by the structure inside their mouths: teeth and baleen.
baleen whales
baleen are structures made out of keratin that look like threads, combined they look like a comb and whales use them to filter food from the water they put in their mouths. baleen whales are usually the biggest whales in the order, with the blue whale and the humpback whale being the most popular ones, really huge beings.
blue whale
despite their name, blue whales look kind of grey, their body is long and flat, they look like a ferret that was pet a little too much and became flattened. these are the biggest mammals in the world, i will look up their size later, because numbers don't really do it for me.
a common trend that we will talk about will be whaling, the event in which human beings hunt whales in great numbers for profit, without a care in maintaining their natural order. blue whales were affected by this and became a vulnerable species, going from hundreds of thousands of individuals to around 500 today.
humpback whale
when people think if whales, this one is probably the one they're thinking of. humpback whales are known for their dark grey back and white chin, which looks like a rough beard. humpback whales have a bit of a hump on their backs and a small dorsal fin. their rough skin is usually covered in barnacles.
humpback whales were also heavily affected by whaling, but they have been able to recover and have a population similar to the one before insdustrial whaling. in fact, humpback whales are one of the most common whales for whale watching.
right whale
whaling
bowhead whale
frown
other baleen whales
toothed whales
this group of whales is a diverse group with lots of personality. here we can find orcas, dolphins and porpoises, which are cetaceans but not always called whales because of their shape and size. toothed whales all share an additional feature besides having teeth: echoloaction, which is a method used for locating surroundings and other whales by making clicking sounds. toothed whales have an organ called spermaceti, which is full of a waxy substance and it's used to amplify these clicks. this organ is located inside their head, so all these whales have big heads.
sperm whale
first of all, sperm refers to the waxy substance they have in the spermaceti. sperm whales have tons of it (literally), since they're enormous and their head is like a third of their size, that's why they were named after it, but that's also the reason why they were hunted so much. their heads look like a rectangle and their spermaceti allows them to make the loudest sound produced by any animal ever. their skin is usually grey, although there is one famous albino sperm whale called moby dick.
orca whale
orca whales are known for their easily recognizeable color pattern and their strategic hunting skills. orcas have a black back, a white belly and white patches on their body, usually around their eyes, too. orcas aren't usually hunted by humans, i guess because they're considered more of a predator than other whales.
beluga whale
bouncy
narwhal
tooth
dolphins
many
porpoises
i dont know much about them
