| This image shows a blue whale pair likely composed of a mother and calf. Blue whale calves will accompany their mothers for approximately a year before being weaned. Female blue whales are larger than males, an adaptation enabling a mother to cope with the physical demands of calving and nursing. | The blue whale, Balaenoptera musculus, is likely the largest animal ever to have lived on Earth. Depending on which expert is cited, blue whales once attained lengths of 100 to 120 feet (32 meters) and have weighed up to 160 tons (145 metric tonnes). Blue whales are found throughout the world's oceans. Estimates put their worldwide population at approximately 10% that of prewhaling size, and blue whales are listed as endangered throughout their range. | Blue whale blows, emitted from a blue whale's twin blowholes as it breathes at the ocean's surface, can reach 30' into the air and can be seen and heard for miles. | Blue whales can swim fast, with burst up to 20 knots. Long and streamlined, they are capable of sustaining speeds of 5 to 10 knots while traveling or foraging for food. Enormous muscles in a blue whale's caudal flanks and peduncle power its wide flukes up and down. | Note the hydronamic shape of a blue whale's rostrum (head). This, along with its broad, flat fluke and relatively long, narrow body, is an adaptation to the considerable travel blue whales undergo transitting from warm calving waters to cool food-rich waters. In this photo, the outline of this blue whale's U-shaped upper lip bone is easily discerned. This bone is more massive than any other in the animal kingdom. | | Blue whales are most easily identified by their huge size, tall blows (up to 30 feet high), blue/gray mottled skin color, and typically rounded (falcate) dorsal fin. Skin pigment patterns along the dorsal ridge, near the dorsal fin, are photographed by scientists in order to identify individual whales. The tips of blue whale fluke tips are rather pointed, and the trailing edge of the fluke is usually smooth and straight with a median notch. Blue whales are closely related to fin whales (Balaenoptera physalus ), which are also huge, but the body of a blue whale is mottled and lighter in color and its dorsal fin is not as tall and pronounced as that of the fin whale. Also, the right lip and baleen plate of the fin whale is light colored and the underside of its body is white. (Blue and fin whales are thought to occasionally interbreed (Calambokidis)). Seen from a distance, blue whales resting or swimming just below the surface appear to be large sandbars. | Scientists estimate that the largest blue ever to have lived probably weighed more than 200 tons -- 400,000 pounds -- and was more massive than an entire herd of thirty African elephants. A truly impressive beast, indeed. Blue whales dwarf even the largest dinosaurs, being nearly twice the size of the largest prehistoric land dweller Brachiosaurus. A small child could crawl through the chambers of a blue whale's immense heart, or out one of its twin blowholes. Scientific accounts cite individual blue whales nearly 100 feet in length while less reliable whaling records reported giants up to 110 feet long. The largest subspecies of blue whale, intermedia, inhabits Antarctic regions while the slightly smaller musculus is found in northern hemisphere oceans. | Blue whales often raise their flukes out of the water as they begin a steep dive. In this photo, note the blue whale's thick caudal stem which powers the fluke up and down -- it is composed of the strongest group of muscles in the animal kingdom. | These photographs, and all of our others of blue whales, are of the eastern North Pacific stock, a population that ranges from Baja California to at least as north as Oregon. Whales from this stock are often seen migrating north along the Pacific coast in spring and summer, typically stopping near Point Conception or the Farallon Islands to feed on aggregations of krill in August and September. | Do blue whales socialize? Of course! But how they find one another across miles of ocean, what brings them together, and what they do when in one another's company is still largely a mystery. | What does a huge blue whale eat? Tons (literally) of tiny euphasiid krill, such as Thysanoessa spinifera. | Blue whales are also known to feed on aggregations of pelagic red crabs, Pleuroncodes planipes.
Pelagic red crab, Pleuroncodes planipes, Mexico |
