# Blue Whale (*Balaenoptera musculus*)

> The blue whale is the largest animal known to have ever existed, reaching up to 30 m (98 ft) long and 180 tonnes. It feeds almost entirely on tiny krill, eating up to 4 tonnes a day, and its heart alone can weigh as much as a small car. Blue whales can live 80 to 90 years.

- **Category:** Mammal
- **Conservation status (IUCN):** Endangered
- **Range:** All major oceans, from polar feeding grounds to tropical breeding waters.
- **Canonical page:** https://globalanimalguide.org/animals/blue-whale/
- **Last reviewed:** 2026-07-16

## Scientific classification

- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Mammalia
- **Order:** Artiodactyla
- **Family:** Balaenopteridae
- **Genus:** Balaenoptera

## Facts at a glance

| Attribute | Value |
| --- | --- |
| Scientific name | Balaenoptera musculus |
| Diet | Carnivore (krill) |
| Habitat | Open oceans worldwide |
| Lifespan | 80–90 years |
| Length | Up to 30 m (98 ft) |
| Weight | Up to 180 tonnes |
| Conservation status | Endangered (IUCN) |

## The largest animal ever

Blue whales are bigger than any dinosaur known to science. Their tongue alone can weigh as much as an elephant, and their heart can be the size of a small car. A newborn calf is already around 7 m long and gains roughly 90 kg every day in its first months.

## Feeding on the tiny

Despite their size, blue whales eat some of the smallest animals in the ocean: shrimp-like krill. They feed by gulping huge volumes of water and filtering out krill through baleen plates, consuming up to 4 tonnes of krill on a single feeding day.

## Communication

Blue whales produce some of the loudest and lowest-frequency sounds of any animal. These powerful calls can travel hundreds of kilometers through the ocean, helping whales communicate across vast distances.

## Conservation

Blue whales were hunted to the brink of extinction during 20th-century commercial whaling. Although they have been protected since the 1960s, recovery is slow, and they remain Endangered, facing threats from ship strikes, entanglement, and ocean change.

## Feeding on krill

Blue whales are filter feeders that strain tiny shrimp-like krill through baleen plates. During the feeding season an adult can eat up to 4 tonnes of krill a day, lunging through dense swarms and gulping enormous volumes of water before pushing it back out through the baleen.

## Frequently asked questions

### How big is a blue whale?

Blue whales can reach about 30 m (98 ft) long and weigh up to 180 tonnes, making them the largest animals ever to have existed.

### Are blue whales endangered?

Yes. After being hunted nearly to extinction in the 20th century, blue whales are listed as Endangered, though some populations are slowly recovering under international protection.

### What is the largest animal in the world?

The blue whale is the largest animal known to have ever lived, reaching up to 30 m (98 ft) in length and weighing as much as 180 tonnes, larger than any dinosaur.

### What do blue whales eat?

Blue whales eat almost exclusively krill, tiny shrimp-like crustaceans. They can consume up to 4 tonnes of krill in a single day during feeding season.

### How big is a blue whale's heart?

A blue whale's heart can weigh around 180 kg, roughly the size of a small car, making it the largest heart of any animal.

### How long do blue whales live?

Blue whales are believed to live 80 to 90 years on average, and some individuals may live even longer.

### How loud are blue whales?

Blue whales are among the loudest animals on Earth. Their low-frequency calls can exceed 180 decibels and travel hundreds of kilometers across the ocean.

## Sources

- Cooke, J. G. (2018). Balaenoptera musculus. IUCN Red List of Threatened Species.
- [Animal Diversity Web — Balaenoptera musculus. University of Michigan Museum of Zoology.](https://animaldiversity.org/accounts/Balaenoptera_musculus/)
- Nowak, R. M. (1999). Walker's Mammals of the World (6th ed.). Johns Hopkins University Press.

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Source: Global Animal Guide (https://globalanimalguide.org/animals/blue-whale/). Licensed CC BY-NC 4.0 — free for non-commercial reuse with attribution.