Humpback whale, a baleen whale Whales are warm-blooded, air-breathing marine mammals. They are the largest animals that ever lived, even larger than the largest dinosaurs. Whales, porpoises and dolphins are known to scientists as cetaceans. There are 83 cetacean species, including 65 species of whale. The skin of these creatures tends to be rubbery and smooth. Most whale fetuses have hair on their heads but lose it by the time they are born. Some species of whale have small tufts of hair around their lips. Others have some near their blowholes or on bumps on their head.
Whale males are called bulls. Females are called cows. Young whales are called calves. Groups of whales are called herds, pods, schools, grinds or gams. The sex of whales, often difficult to determine, is identified by observing the genital slits.
There are two categories of whale: baleen whales and toothed whales. Baleen whales have filter-like baleens that allow then to feed on krill, fish and plankton. Blue whales, right whales, humpback whales. fin whales, gray whales and minke whales are all baleen whales. Toothed whales include sperm whales, narwhals, belugas, Baird's beaked whales, pilot whales, killer whales, bottlenose whales and dolphins and porpoises.
Baleen whales evolved from toothed whale. This points is demonstrated by baleen whale fetuses that grow teeth while in the womb but reabsorb them before birth.
sperm whale, a toothed whale Book: The Grandest of Lives: Eye to Eye With Whales by Douglas H. Chadwick (Sierra Club, 2006); The Whale, In Search of the Giants of the Sea by Philip Hoare (Ecco, 2010), a an erudite and literary look at whales and whaling and winner of the 2009 BBC Samuel Johnson Prize for Non-Fiction; The Book of Whales by Richard Ellis.
Sources: Britain-based Whale and Dolphin Conservation Society; International Whaling Commission (IWC)
Websites and Resources: National Oceanic and Atmospheric Administration noaa.gov/ocean ; Smithsonian Oceans Portal ocean.si.edu/ocean-life-ecosystems ; Ocean World oceanworld.tamu.edu ; Woods Hole Oceanographic Institute whoi.edu ; Cousteau Society cousteau.org ; Montery Bay Aquarium montereybayaquarium.org
Websites and Resources on Fish and Marine Life: MarineBio marinebio.org/oceans/creatures ; Census of Marine Life coml.org/image-gallery ; Marine Life Images marinelifeimages.com/photostore/index ; Marine Species Gallery scuba-equipment-usa.com/marine
Whale Size and Characteristics
killer whale size Some baleen whales have an aorta large enough for a child to crawl through. Their brains are by far the largest of any animal. Even so, their throats are so narrow that even medium-size fish won't fit. This is because most of their food is plankton or crustaceans smaller than shrimp.
Whales are able to attain their huge size because water supports their weight. Out of water, a whale’s huge weight collapses the whale's lungs and it suffocates. The whale’s water habitat is the main reason they have been able to become larger than land-bound dinosaurs that needed to prop up their bodies to counteract gravity. The immense size of whales makes it easier for them to maintain their body temperature because the larger something is the lower the ratio is between volume and surface area.
Humpback whale size Whales are streamlined like fish. They have no external genitals and all their sensory organs are recessed into slits so the can move through the water with less friction and drag. The fastest whales can swim at around 23 mph.
Whales live a long time. One whale is known to have lived to the age of 87. Others are believed to live more than a century. In May 2007, Alaskan Eskimos caught a 50-ton bowhead whale and made an interesting discovery: impeded deep in the animal blubber was a harpoon point made in New Bedford, Massachusetts in the 1880s. It seems that the harpoon was fired sometime around then, making the age of the whale at least 130 years old.
anatomy of a killer whale, >br> a toothed whale Whales have skeletal features similar to land mammals. Their flippers have a similar skeletal structure as man's arm, hand and fingers. Their hind limbs have disappeared but a pelvis remains. The front flipper are remnants of forelimbs that date back to the days when whale ancestors moved around on land. The hind limbs have disappeared altogether except for small relic bones found deep in the flanks.
Most whales have a small dorsal fin, two flippers behind the head, one on each side, and a fin-like tail called a fluke, which is horizontal as opposed to vertical like the tail of fish. Whales move with powerful up and down and diagonal motions of their body and fluke as opposed to the side by side motion of fish. In Moby Dick Herman Melville wrote: “In no living thing are the lines of beauty more exquisitely defined than in the crescentic borders of these flukes.”
Humpback, minke, fin, sei and blue whales are sometimes called roquals. Unlike right whales, they have a small dorsal fin and long furrowlike pleats on the throat and breast that expand when the whale has a mouthful of food and water. The pleats allow the whales to take in more food and grow to gargantuan sizes.
Whale bodies are covered by a thick layer of blubber---milky, white fat underneath a whale's skin.”that can be up to 80 centimeters deep and often makes more than half of the whales total body weight. Blubber is a great insulator in cold seas. It helps a whale store energy and provides nourishment when there isn't much to eat.
Blubber also helps keeps whales a float. Starving whales often loose so much blubber they can no longer remain a afloat, and have to exert great effort into surfacing and breathing. Some perhaps die because they are too exhausted to surface.
Baleens and Blowholes
Gray whale baleen Baleen whales have a baleen or whale bone instead of teeth. Baleens are like nets or strainers. They sift out plankton, krill, small crustaceans and small fish from the water. The baleen of a large whale is 6 to 14 feet long and consists of a dense fringe of 250 to 300 bristly slats. The throat is a only a few inches wide.
Baleens are sheets of horn, feathered at the edges that hang down like stiff curtains from the upper jaw. They are made from keratin the same stiff material that forms mammal hair and claws. In the old days flexible baleen was used to make corsets, umbrella ribs, clock springs and riding whips.
Whales have lungs like humans not gills like fish. Rather than a nose they have a large nostril called a blowhole on their back behind their head, which is used to inhale air and exhale carbon dioxide when the whale surfaces. The warm exhaled breath shoots out the blowhole with a loud noise and sometimes produces a visible water spout. The blowhole of many whale species is surrounded by splash guard that diverts water away from the nostrils.
right whale blowhole Why do whales produce visible spouts of vapor when they breathe? Human's after all don't exhale water when they breath. Sometimes exhaled whale breath condenses into visible vapor in cold air like the condensed breath of humans on a cold day. But whales also produce spouts on warm days.Dr. Roger Payne, a biologist who has spent many years studying whales, said, "Observation seem to suggest that a visible spout results principally from the atomization of water surrounding the nostrils when the animal exhales deeply." Invisible spouts usually alternate with visible ones, and there are generally more spouts on windy days. Whales being pursued will sometimes exhales underwater to escape detection. It is their visible spouts after all that made whales so easy to spot and such easy prey for whalers.┴
Toothed whales have a single blow hole while baleen whales have one that is split in two. The old whaling shout "Thar she blows" referred to the sound and the sight of vapor being expelled, which also includes seawater that collects in the air passages. The blowhole has a valve that closes when the whale dives.
Whales are very efficient respirators. They exchange 90 percent of the air in their lungs on each breath (humans exchange about 15 percent). As a result of this efficiency whales can breath at very long intervals and stay submerged for long periods of time. Because their windpipe is connected to their blowhole whales can open their mouths under water without drowning.
Whales have poor eyesight and poor senses of smell. Their eyes are very small and swivel inside its socket just like a human eye. The eyes are of little use because even in clear water they are protected from salt water by an oily substance. Whale have no external ears. Their tiny ear canals are only a few centimeters thick. Even so they have acute senses of hearing: the product of sensory organs in their head not their ears. Some species are believed to be able to detect sounds produced hundreds of kilometers away. Baleen whales, many toothed whales and dolphins use echolocation to locate objects.
baleen whale parts
Whales can hear an extremely wide range of sounds, ranging from high sounds that are 13 times higher than the highest sounds that humans can hear to low sounds also beyon human hearing that can travel great distances in the ocean. Ear bones of whales and dolphins are the densest in the world. The are hollow and need to be incredibly strong to protect the delicate inner ear tissues from the pressure of deep dives. Some scientists believe sound travels from the jaw to the ear through a big lobe of fat. The outer ear is essentially useless.
Whale and dolphins are sometimes grouped into three categories depending on what range of sounds they hear best: 1) those that hear higher frequencies than the human range: 2) those that hear mid-range frequencies; 3) those that hear lower frequencies than the human range. Among those in the first group are river dolphins that navigate in cloudy water. The second group includes whales and dolphins that use echolocation to spot prey. Most of those in the third group are baleen whales that use low frequencies to send sound hundreds and thousands of miles across the ocean.
Whales can dive to depths of 4,000 feet and stay submerged for more than an hour. Bottlenose whales dive repeatedly to depths more than 1.6 kilometers and are no worse for the wear even though metal placed under the kind of pressure found at those depths would crumble like aluminum foil and a human would dissolve into jelly in a matter of seconds.
Cetacea (whales and dolphins)
Whale muscles have a large concentration of a oxygen-storing substance called myoglobin. It gives whale meat its deep red color and allows them to dive for such long periods of time and go 40 minutes between breaths.
Scientists have long wondered exactly how dolphins, whales and seals can stay under water so long. The secret seems to be that they float rather than swim downwards to conserve energy and do not use up oxygen unnecessarily. The stay as still as possible on the way down and use their energy to catch prey and swim back up. Whales, seals and dolphins all seem to use the same strategy. Scientists were able to observe his phenomena by strapping critter cam cameras on bottlenose dolphins, Wendell seals and even a blue whale.
Whale Behavior and Intelligence
Whales ordinarily come into view only briefly when the surface to breath. What they do much of the rest of the time when they are in under the water is unknown. Some scientist believe that whales "sail" by raising their tails out of the water and catching the wind.
Sperm whale skeleton
Some whales have brains the size of sofas. There are believed to be able to store huge amounts of data and remember things for a long time. Much of a whale's brain capacity is thought to be devoted to acoustic perception.
Whales are considered the world's highest jumpers. They can leap up to 20 feet out of the water. Whale leaping out of the water is called breaching. The reason for this behavior is unknown. Some scientists believe they do it to communicate. Others speculate it is to remove parasites or play a role in feeding or looking around. Males breach more than females.
Whales can be very sociable and very individualistic personalities. Some whales grieve over dead like elephants and hoover around dead companions for hours or days. Sometimes they stroke the dead body.
Whales take regular naps between 30 minutes and several hours between dives.
Blue whale penis
Whales produces a variety of sounds. Depending on the species, they can produce clicks, whistles, bleeps, moans or sophisticated "songs." Humpback whales are famous for their songs and the wide range of otherworldly sounds they make. See Humpback Whales
Most baleen whales communicate over long distances with low frequency sounds. Some large whales produce sounds that reach 180 decibels, strong enough to bruise the lungs of humans swimming nearby. Higher frequency sounds are used for echolocation, to define topography and identify the size, identity, distance and location of objects. Noise from shipping and submarines may interfere with whale communications.
Sound travels farther and move five times faster under water than on land and can be funneled by submarine canyons. Loud sounds can be heard with little alteration hundreds of miles away. Whales are believed to able to hear the sound of boat propellers and other whales even if they are very far away and may navigate by bouncing their sonar off underwater topographical features like seamounts and continental shelves.
During the peak of the feeding season, some baleen whales consume 20 percent of their body weight in food every day.
Blue whales, fin whales, and minke whales are known as gulpers. They gulp great mouthfuls of sea water and everything in it---their long furrowlike pleats on the throat and breast pouches expanding as they do. They use their tongues to push the water against their baleens, causing the water to go back out their mouths, swallowing the small animals left behind. Some whales feed on schools of small fish.
See Humpback Whales, Blue Whales
Migrating, Mating and Breeding Whales
Many baleen whales migrate large distances, usually between summer, warm-water breeding areas and winter feeding grounds in the Arctic and Antarctic, where the krill and plankton that baleen whales feed are abundant. Migrating whales often eat vast quantities of food in their feeding area and then eat virtually nothing from the time they begin migrating to their breeding and calving grounds to the time they return. The can go over months without eating, living the entire time off energy stored in their blubber.
feeding humpbacks Whales have a low reproduction rate. They reach sexual maturity between the ages of six and eleven. Their gestation period is usually around a year and most female whales only give birth to a single calf. Whales give birth under water. The calves are able to swim immediately but their lungs are deflated and they need a shove from their mothers to get to the surface to take their first breaths.
Groups of males often pursue a single cow. Agitated males flick their tails, distend their throat pouches, lunge towards each other, lash each either with their tails, blow strings of bubbles. Scars on males are believed to be the result of fights. Young males sometimes engage in what has been described as “ribald form of fencing” with their long penises. While these males clearly seem to enjoy these encounters they also mate with females..
Mothers protect their young from predators and provide guidance and milk. Whale calves consume large quantities of their mother's fat-rich milk for their first year, during which time they double, triple or even quadruple their size. The females milk organs have special muscles that pump out the milk so it doesn't mix with sea water.
The bonding between cow and calf are very intense. The two stay side by side virtually the entire time of the calf's first year of life. Mothers are very protective. Sometimes they will remain with their calves even if they are dead at the cost of their own lives, a trait exploited by whalers who often tried to kill the calf first and then went after the grieving mother. Even in adulthood whales are known to seek out their mothers when under stress.
Whale Predators and Pests and Whale Snow
The only animals that great whales fear are man and killer whales. Killer whales have been observed attacking grays, humpbacks, rights, bryde's, minkes, sperm whales, even blue whales, as well as dolphins. Large sharks are known to feed on porpoises, dolphins and whale carcasses but rarely feed on living whales.
Barnacles and other creatures often attach themselves to whales. They accumulate in cold water and often drop off in warmer water. Humpbacks in the Arctic accumulate up to a half ton of barnacles. Right whale, who also spend a lot of time in cold water, accumulate a lot. Remoras sometimes follow whales around and seabirds land on them. Melville wrote, "Sea fowls are pecking at the small crabs, shellfish, and other sea candies and macaroni, which the Right Whale sometimes carries on his pestilent back."
Orange whale lice on a right whale Whales suffer from a number of ailments that affect humans, including ulcers, teeth cavities and tonsillitis. A number of internal parasites such as 50-foot-long tapeworms have been in whale’s liver, stomach, intestines, lungs, kidneys and brain. One sperm whale was found with 110 pounds of nematodes in its stomach. Whale snouts are often laden with whale lice. They also suffer terribly from inner ear parasites. Whale lice are often benign and even helpful, consuming dead skin.
A dead whale can deliver the equivalency of 2000 years of “marine snow” to the bottom of the ocean. Marine snow is made of bits dead marine life and other organic matter that gently falls through the water column and settles on the sea floor, providing food for many creatures on the sea bottom and in deep water. In the early 2000s, Scientists discovered two new of species worm living in the bones of dead whales found off the California coast.
Sunburned Whales Maybe Caused by the Ozone Hole
Gray whale blowhole In November 2010, “Some whale species off the Mexican coast are showing signs of severe sunburn that might be caused by the damaged ozone layer's decreased ability to block ultraviolet radiation, a study concluded. The seagoing mammals would be particularly vulnerable to the sun damage in part because they need to spend extended periods of time on the ocean's surface to breathe, socialize, and feed their young. Since they don't have fur or feathers, that effectively means they sunbathe naked. [Source: AP, November 10, 2010]
As Laura Martinez-Levasseur, the study's lead author, put it: "Humans can put on clothes or sunglasses---whales can't." Martinez-Levasseur, who works at the Zoological Society of London, spent three years studying whales in the Gulf of California, the teeming body of water that separates Baja California from the Mexican mainland.
Photographs were taken of the whales to chart any visible damage, and small samples---taken with a crossbow-fired dart---were collected to examine the state of their skin cells. Her study, published in the Proceedings of the Royal Society B, seemed to confirm suspicions first raised by one of her whale-watching colleagues: The beasts were showing lesions associated with sun damage, and many of their skin samples revealed patterns of dead cells associated with exposure to the powerful ultraviolet radiation emitted by the sun.
Scars from cookie-cutter shark
bites on Gray's beaked whale As with humans, the lighter-skinned whales seemed to have the most difficulty dealing with the sun. Blue whales had more severe skin damage than their darker-skinned counterparts, fin whales and sperm whales, even though the latter spend bigger chunks of time at the surface. "A likely candidate is rising UVR as a result of either ozone depletion, or a change in the level of cloud cover," Martinez-Levasseur added. The ozone layer, which helps insulate Earth from ultraviolet rays, has been thinning for years under the influence of ozone-eating chemicals known as CFCs. The emission of those chemicals has since largely been curbed, and the ozone layer is undergoing a slow recovery.
For whales, the potential danger from the sun's rays are just one more environmental stress. All species tracked in this study are considered endangered or vulnerable by the International Union for Conservation of Nature. If it's shown that the skin damage is leading to cancer, then "this could be a serious threat," according to Simon Ingram, who teaches marine conservation at England's University of Plymouth and wasn't involved with the study.
So far, there were no indications of skin cancer among the whales studied, although Martinez-Levasseur noted that only tiny samples were taken of the massive animals. She said one of her next projects will be to examine how well whales' cells hold up under the increased ultraviolet radiation---and whether whales' pigmentation darkens as a result of their time spent out in the sun. In other words, she wants "to be able to see if they're tanning."
Image Sources: Wikimedia Commons
Text Sources: Mostly National Geographic articles. Also the New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Natural History magazine, Discover magazine, Times of London, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Lonely Planet Guides, Compton’s Encyclopedia and various books and other publications.
© 2009 Jeffrey Hays
Last updated March 2012