The blue whale, Balaenoptera musculus, is 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 worlds oceans. Estimates put their worldwide population at approximately 10% that of prewhaling size, and blue whales are listed as endangered throughout their range. The population of blue whales in the Southern Ocean was hunted especially hard.
Two of the images above show blue whale pairs likely composed of a mother with calf/subadult. 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.
Blue whales can swim fast, with bursts 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.
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Blue whale, exhaling, note splashguard foreward of blowholes, Baja California.
Image: 03045
Species: Balaenoptera musculus
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The splashguard of this approaching blue whale pushes water aside so that it can open its blowholes (which are just behind the splashguard) to breathe. Open ocean offshore of San Diego. San Diego, California, USA.
Image: 07520
Species: Balaenoptera musculus
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An enormous blue whale rounds out (hunches up its back) before diving. Note the distinctive mottled skin pattern and small, falcate dorsal fin. Open ocean offshore of San Diego. San Diego, California, USA.
Image: 07527
Species: Balaenoptera musculus
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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 a blue whale’s fluke 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.
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An enormous blue whale swims in front of whale watchers on a private yacht. Only a small portion of the whale, which dwarfs the boat and may be 70 feet or more in length, can be seen. Open ocean offshore of San Diego. San Diego, California, USA.
Image: 07541
Species: Balaenoptera musculus
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An enormous blue whale is stretched out at the surface, resting, breathing and slowly swimming, during a break between feeding dives. Open ocean offshore of San Diego. San Diego, California, USA.
Image: 07534
Species: Balaenoptera musculus
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A blue whale blows (spouts) just as it surfaces after spending time at depth in search of food. Open ocean offshore of San Diego. San Diego, California, USA.
Image: 07544
Species: Balaenoptera musculus
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What does a huge blue whale eat? Tons (literally) of tiny euphasiid krill, such as Thysanoessa spinifera (center). Blue whales are also known to feed on aggregations of pelagic red crabs Pleuroncodes planipes (left and right).
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.
Dorsal flank showing characteristic mottled skin patterns. This particular blue whale, observed in northern Mexico, also has a few dozen remora probably acquired in warmer waters to the south.
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. Researchers around the world are gradually coming to understand the life of this greatest of whales through direct observation, remote sensing with satellite tags, and by eavesdropping on whale vocalizations with sophisticated hydrophones.
All of the above photographs are of blue whales in 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. For more information about blue whales, read Blue Whales by John Calambokidis and Gretchen Steiger, Voyageur Press; ISBN: 0896583384.
Keywords: blue whale, photo, underwater, picture, Balaenoptera musculus, aerial, photography, photograph, calf, baby, spout, tail, fluke, blowhole, image.
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