The Biggest Whale in the World is 100 Feet Long!

The biggest cetacean in the world is the blue whale, whose scientific name is Balaenoptera musculus. This huge animal is approximately 100 feet long. Some can reach slightly longer, but this is a rare occurrence. Blue whales inhabit oceans all around the world, except the Arctic. However, these gentle giants are actually classed as endangered, with a population of 10,000 to 25,000. So, what else do we know about the blue whale? Let’s find out!

Where Do Blue Whales Live?

There are four subspecies of blue whales and they inhabit oceans all around the world, except for the Arctic. However, compared to the northern hemisphere, their population is higher in the southern hemisphere. The animals have also been known to visit the shallow waters near the shore and have been seen off the coast of California and Mexico. Some migrate to feeding grounds and breeding grounds, while others stay in the same place all year round.

What Do They Look Like?

The blue whale is fusiform, which means it is shaped like a spindle that tapers towards both ends. This cetacean tapers mostly toward its tail. It is light blue-gray above and sometimes mottled with gray, but seen through the water, it appears blue. The belly is sometimes yellow, which gives the animal its other name, sulfur bottom. The yellow isn’t the animal’s natural coloring but is caused by diatoms that cling to its belly as it swims in cold waters.

The animal has a broad, flat beak or rostrum that’s almost shaped like a U. It has a ridge down the center of its back and has two blowholes. When it comes up for air, the blow is high and shaped like an oval. The dorsal fin is very small, shaped like a triangle, and rather far back on the body. The blue whale also has grooves on its throat that extend just past its navel. These grooves allow the throat to expand as it takes in food and water. When the blue whale dives, it lifts its tail out of the water. This is called fluking, and not every whale does this.

How Big Are Blue Whales?

Blue whales are typically 86 to 100 feet long, although some may occasionally be a little longer. They can also weigh up to a maximum of 219 short tons. Females are also usually a little larger than males, both in length and in weight.

Nature has allowed blue whales to grow so large because they live in the ocean. The ocean is not only big enough to accommodate a lot of creatures the size of Balaenoptera musculus, but the growth of the animal isn’t constrained by gravity the way it would be if it still lived on land.

Even blue whale calves are pretty big too, as they are approximately 23 feet long at birth and can weigh as much as 6,200 pounds. They nurse from their mother until they are approximately six to eight months old. The milk of whales is full of fat, and the calf gains about 198 pounds every day just from ingesting it.

Blue Whale Diet

The blue whale is a filter feeder and has a row of bristly parallel plates in its upper jaw called baleen. Baleen, which is made of the same stuff as fingernails, is used to sift its food out of the water. Most populations of blue whales famously eat krill, a tiny crustacean that resembles a shrimp and is related to it. Depending on the time of year, the blue whale can eat four tons of krill every day. When the blue whale eats, it simply opens its mouth and lunges forward into a great cloud of krill. The ventral pleats allow its throat to expand like bellows. Then, it uses its baleen to strain much of the water out of its mouth and swallows the krill.

Do Blue Whales Sing?

Blue whales do “sing,” but their vocalizations are not nearly as complex as those of humpback whales. Still, scientists can distinguish a population of whales by their vocalizations. The vocalizations also vary depending on the season, where the animal lives, what it’s doing at the moment, and whether it’s morning, afternoon, or night. What distinguishes the song of the blue whale is that it is loud and low. This animal can produce a sound that is as loud as 180 decibels. The frequency is most often between 8 and 25 Hz. The latter frequency just about enters the range of human hearing.

Because the vocalizations are so loud and so low, they are able to communicate with whales as much as 500 miles away. Whales use their vocalizations to both talk to other whales far away and to navigate.

Threats to the Blue Whale

Due to their huge size, the blue whale doesn’t have many natural predators. In fact, the only other animal known to prey on them is the orca. These apex predators hunt in packs and have been known to attack and kill blue whale calves, although most adults can escape. The blue whale, unsurprisingly, is not the ocean’s fastest swimmer, but it can achieve a maximum of 30mph in short bursts.

Thanks to the International Whaling Commission, blue whales are no longer hunted, something that nearly drove them to extinction. However, they do face other threats. They are still hit and killed by ships, and a few have been entangled in fishing gear. Climate change also impacts blue whales adversely because it can reduce the population of krill or make krill harder to find.

Blue whales have a slow reproduction rate. They typically reach sexual maturity between five and fifteen years of age. Pregnancy lasts between ten months and one year, and the females only give birth to one calf every two to four years.

How Long Do They Live?

Scientists estimate that blue whales live about 80 to 90 years in the wild, though the oldest known lived to be 110. How scientists figure out how long blue whales live is interesting. As the animal matures, its ears produce earwax that eventually forms a plug. The layers of wax, like the rings in a cross-section of a tree trunk, tell the scientist the whale’s age. By the way, the earwax doesn’t interfere with the whale’s ability to hear but actually enhances it by transmitting sound waves.