Balaenoptera musculus

Blue Whales are solitary or found in small groups known as pairs or pods. They are known for their exceptional diving ability, able to stay submerged for up to an hour and dive to depths of approximately 500 meters (1,640 feet) to feed. Their diet consists almost exclusively of tiny shrimp-like animals called krill, with an adult blue whale consuming up to 4 tons of krill per day during the feeding season. Blue Whales communicate using a series of loud, low-frequency sounds or songs, which can travel for hundreds of miles underwater.

Blue Whales reach sexual maturity at around 10 years of age. Their breeding season is in the winter, with a gestation period of about 11 months. Females typically give birth to a single calf every two to three years. At birth, blue whale calves are already among the largest creatures on Earth, measuring up to 8 meters (26 feet) in length and weighing as much as 2.5 metric tons (about 5,500 pounds).

Blue Whales are known for their impressive size, with adult females being larger than males. The largest specimens can reach lengths of up to 100 feet (30 meters) and weigh as much as 200 tons (about 441,000 pounds). Their bodies are long and slender, and they are predominantly blue-gray in color, with lighter undersides. One of the blue whale's most distinctive features is its blow or spout, which can reach heights of up to 30 feet (9 meters) when it exhales air upon surfacing.

Blue Whales were abundant in all the world's oceans until the beginning of the 20th century when they were hunted nearly to extinction for their blubber, meat, and oil. Whaling severely reduced their populations, and they are now considered endangered.

Today, Blue Whales are protected worldwide, with hunting banned by the International Whaling Commission (IWC) since 1966. Despite this protection, their populations have only partially recovered, and they continue to face threats from ship strikes, entanglement in fishing gear, and the impacts of climate change on their krill prey. Current estimates suggest there are between 10,000 to 25,000 blue whales globally, classifying them as endangered on the IUCN Red List. Conservation efforts are focused on protecting their habitats, monitoring populations, and implementing measures to mitigate threats.