Sulfur-bottom Whale (Balaenotere muculus)




Sulfur-bottom whales, also known as blue whales, are quite popular since they are the largest animal in the world. Still, many people don’t know a thing about sulfur-bottoms except that they are big whales.

Food And Hunting

Even though sulfur-bottoms are the largest animals in the world they feed almost exclusively on one of the smallest: krill, a shrimp like crustacean in the plankton family. Occasionally sulfur-bottoms will eat other types of plankton and small fish too.

Sulfur-bottom whales, instead of teeth, have baleen plates that they use to catch prey. Baleen plates are a lot like flat palm tree bark that hangs down from a whale’s mouth with hard hairs facing inside the mouth. Only ten species of cetacean have baleen. These whales are called baleen whales.

So how do sulfur-bottoms use their baleen as a filter? After catching prey by taking in a mouthful of plankton filled-water, a sulfur-bottom will hold both the prey and the water in its mouth. The whale then lifts its tongue and forces the water out through its baleen, which catches the prey that would have been forced out with the water. That is how sulfur-bottoms use their baleen.

Other Names

Other names for sulfur-bottoms are blue whale, Sibbald’s rorqual, and great northern rorqual.

The name blue whale is the most common name for the sulfur-bottom. I don’t use the name blue whale because it plants a wrong image. They are grayish blue but not blue. In fact there is more gray in the color than blue. Some aren’t blue at all, but brown instead. The name sulfur-bottom comes from the fact that they are the only baleen whales to have a sulfur-colored underside.


Despite their common name “blue whale” sulfur-bottoms are blue-gray. It is true though that they have a more blueish tint to their main color than most other whales, but some are medium brown.

A sulfur-bottom’s back and both its sides are all one pattern. They may be gray, blue/gray, or brown. The underside can be white, a lighter and darker shade of blue-gray, or a sulfur color.


Sulfur-bottoms can be found all over the world. The main populations are in the North Atlantic, North Pacific, and southern hemisphere. They are not as common in other places.

Being such large animals, sulfur-bottoms rarely (if ever) come close enough to be seen from the shore. To come to the shore they would take a great risk of becoming stranded on the beach. It is rare, but sulfur-bottoms have become stranded on the beach and died.

Record Breaker

Sulfur-bottoms are true record breakers. They are the largest animal on earth at a maximum length of 110 feet. The tongue is as big as an elephant, and some of the sulfur-bottom’s blood vessels are so large you could swim through them.

Sulfur-bottoms are also the heaviest animals on earth at a maximum weight of 220 tons. The heart alone weighs as much as a car.

Whaling Out Sulfur-bottoms

A few hundred years ago many breeds of whale were heavily whaled and are now endangered. Sulfur-bottoms are one of those unfortunate breeds.

So what is whaling? Whaling is a practice of hunting whales. Today whaling is illegal because it made many species of cetacean endangered. If whaling had not stopped, sulfur-bottoms may be extinct.

Whaling in the past was very cruel. Once a whale was spotted from a ship, whalers (men who hunted whales) would row off in rowboats from their ship and throw harpoon after harpoon into a whale’s back. Eventually the whale would die from the harpoons. It was a rough death. Then, instead of becoming more humane whaling became less humane. For instance: One explosive harpoon blew a huge hole in the side of a minke whale. It took nearly an hour for the minke whale to bleed to death and die.

Sulfur-bottom whales are now endangered. Even though they are the biggest animal on earth they are rare and very hard to find. Many of the people who make films about sulfur-bottoms have to search for days just to find one or two, and may only see them for a minute or less. Humans have done real damage to many breeds of whale, such as sulfur-bottoms.


One thought on “Sulfur-bottom Whale (Balaenotere muculus)

Leave a comment...

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s