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Adult female Cuvier’s beaked whale (Ziphius cavirostris). Photo by Robin Baird.
There are entire species of large mammals living today on Earth which have never been seen alive by humans. Even though they can grow larger than elephants, their numbers and habits are unknown. We might not even know all extant species in the family. These mystery mammals are the beaked whales (family Ziphiidae) masters of deep ocean diving. The family is comprised of at least 21 different species, only 3 of which are well known (thanks to whale hunting in previous centuries). Beaked whales are poorly understood because they are rarely on the surface of the ocean where we can observe them. They are capable of diving more than 1,899 meters (6,230 feet) and can stay underwater for almost an hour and a half. Beaked whales live in the black–down among the underwater seamounts, canyons, and abyssal plains. We only know them from the examination of dead specimens: indeed, for some species of beaked whales that is quite literally true and they have only been seen when dead.
Small Beaked Whales (an illustration by Brett Jarrett)
Beaked whales grow to sizes of 4 to 13 metres (13 to 43 ft) depending on the species. They are sexually dimorphic—the males are a different size than the females. Additionally male whales have prominent domed foreheads and a pair of fighting teeth for dueling and sexual display (these teeth do not fully develop in females). Beaked whales feed on squid, and, to a lesser extent, fishes and invertebrates which they capture from the ocean bottom by means of suction. In order to produce this suction effect, the whales have highly nimble tongues and throat grooves.
The most distinctive features of beaked whales (save perhaps from their rostral “beaks”) are the body features which allow them to dive so deeply and then hunt in the dark crushing waters. The lungs of beaked whales collapse at a certain pressure—most likely as a way to minimize the dangers of nitrogen transfer. Their livers and spleens are huge in order to deal with the dangerous metabolic bi-products of prolonged periods when they are unable to breathe. Additionally, their blood and muscle tissue is capable of capturing and storing substantially greater quantities of oxygen than the tissue of other mammals. Beaked whales can pull their pectoral flippers into grooves which run along the sides of their bodies and thus become more streamlined.
Sowerby’s Beaked Whale (Mesoplodon bidens)
In order to find their way in the deep ocean, the whales rely on sophisticated acoustic echo-location organs. Lips behind the blowhole produce high pitched vibrations which bounce off of prey and obstacles. Echoes from these vibrations are then picked up and focused into the whales’ sensory organs by special fat deposits and bone structures. Unfortunately this method of echolocation seems to make beaked whales extremely sensitive to sonar. Resurfacing whales are unable to avoid the amplified sound waves and can suffer injuries to their sensory organs (or even to their large delicate livers). Additionally, it is theorized that Beaked whales may try to resurface too quickly to avoid sonar and therefore risk decompression sickness.
(Photo: credit Nan Hauser & Hoyt Peckham, CCRC)
Humankind has also been fishing ever deeper waters as fish stocks crash—which involves the whales in by-catch issues. Hopefully we will learn more about this family of enigmatic divers (and become more responsible stewards of the ocean) so that the beaked whales do not vanish before we even get to know them.
The Mountains of Antarctica as seen from the Southern Ocean
The great Southern Ocean which swirls in a clockwise circle around Antarctica is home to many of the Earth’s largest animals. Blue whales come here to gorge on vast schools of krill. Among the icebergs and the towering waves, southern elephant seals (the largest member of the order Carnivora) fight duels to build their harems, and highly intelligent killer whales hunt together in pods. There are populations of sperm whales living in the Southern ocean as well and these leviathans dive to the cold floor of the world hunting for the world’s largest mollusk, a huge cephalopod which can only be found in the Southern Ocean. In fact this bizarre creature, the colossal squid (Mesonychoteuthis hamiltoni) is also the world’s largest invertebrate. Also known as the Antarctic squid or the giant cranch squid, the colossal squid lives in the abyssal depths. Unlike other squid, the colossal squid does not have tentacles–its powerful arms are studded with sharp hooks (much like the long-extinct belemnites). Some of these hooks swivel while others have three barbs in the manner of a fish spear.
The Colossal Squid (Mesonychoteuthis hamiltoni)
The measurements of the colossal squid are staggering. Its eye alone (the largest of any known creature) measures 27 centimetres (11 in). A fully grown adult squid is estimated to be 12–15 metres (39–49ft) long. Although giant squid have longer tentacles, the colossal squid a long stout mantles and are thus much more massive. Their upper weight limits are unknown but are well over 500 kg (+1000 lbs).
The colossal squid is believed to be an ambush predator, which lurks in the depths waiting for chaetognatha, other squid, and benthic fish (such as the Patagonian toothfish) to pounce upon. It is hypothesized that they have a slow metabolism and do no need great reserves of food (unlike the energetic endothermic sperm whales which prey on them). The colossal squid are believed to be sexually dimorphic—the females become much larger than the males.
A rare specimen of colossal squid
There is a reason that so much of this article is couched in ambivalent language such as “estimated”, “believed” and “probably”: colossal squid live in an environment where humankind can barely venture. The colossal squid are fast enough and clever enough to usually evade our nets, lines, and traps (although fishermen trying to catch Patagonian toothfish hooked a 450 kg (990 lb) specimen which was about 39 feet (13 m) long). Additionally our submarines and submersible robots are too slow and noticeable too stalk the squid in the abyssal depths. Other ocean creatures do not suffer from the same problem. Juvenile colossal squid are eaten by beaked whales, elephant seals, sharks, toothfish, and even albatrosses, however the adult squid are so large that only massive sleeper sharks and giant sperm whales can threaten them. Sperm whales are often covered with scars from their battles with the giants but the whales easily have the upper hand. Sperm whale stomachs have been found filled with hooks and beaks (which coincidentally were much larger than those found on the largest squid specimens recovered by humans to date).
Odobenocetops as digitally rendered by the BBC for "Chased by Seamonsters"
This blog has featured posts concerning saber-toothed seals and saber-toothed marsupials but did you know that the oceans around South America once contained a saber-toothed whale? Odobenocetops lived during the Pliocene era (around 2.5 to 5 million years ago). Two similar species are known in the genus from fossils discovered in coastal Peru. An early member of the dolphin superfamily, Odobenocetops was probably more closely related to narwhals and belgugas then to modern dolphins and killer whales.
Measuring only a little longer than 2 meters (6 feet) in length, Odobenocetops was remarkable (at least among whales) for its flexible neck–which could turn 90 degrees. The powerful blunt snout of the endearing little whale suggests that it fed from beds of mollusks and other bottom dwelling shellfish, which it rasped from their shells with a muscular tongue. Additionally, the Odobenocetopsidae had echolocation abilities like modern dolphins–although probably not so amazingly precise, since the extinct whales’ echolocation melons were much smaller than those of living dolphins.
Odobenocetops feeding
Of course the most distinctive features of Odobenocetops were their long spiky teeth running parallel along their sides. Scientists speculate that these tusks could have been used to seek food or as a sensory organ–like the narwhal’s sensitive tusk. Perhaps male whales used their tusks to battle for females, like walruses do (although they seem awfully brittle for such battles). Some males had uneven tusks. The sole known skull of a male Odobenocetops leptodon features a right-hand tusk 1.2 m (4 ft.) long, while the left-hand tusk is only 25 cm (10 in.) long. Since this is the only male O. leptodon skull currently known, it is unclear whether such asymmetry was normal.
It is striking that the whales’ saber teeth were held next to the body and it makes one think that the whale did not execute many sharp turns. A humorous but somewhat sad cartoon which I found unattributed on the web demonstrates the potential drawbacks of the Odobenocetops’ striking saber toothed design.
Aww...the poor whale...
Sedna Statue (from GTA Inuit Art Marketing)
Like the Arctic landscape, Inuit mythology is austere, cruel, strange, and beautiful. Just as the dialects of the Inuit language differ based on geography, so too many of the sacred stories of the Inuit share the same elements yet also vary from one region to the next. One such story is the myth of Sedna—the goddess of marine mammals, the frozen depths of the sea, and of the spirit’s realm below. There are many versions of the tale. Here is my favorite.
Sedna was a beautiful giantess. Her great size was a hardship for her father, who had to spend most of his time hunting in order to feed himself and his daughter. However, because she was so lovely, she had many suitors. Sedna was proud of her looks and her strength, so she rejected every suitor as unworthy of her.
One day a well-dressed stranger came to visit Sedna’s father. Though the visitor’s clothes were opulent and his language was cultured, he kept his hood pulled down so that his face remained in darkness. The stranger talked of his great wealth and the life of ease which Sedna would enjoy if she were his wife. Then he appealed to the father’s greed with gifts of fish, animal skins, and precious materials. Since hunting was bad and his stores were running out, Sedna’s father felt he had little choice but to comply–so he drugged his daughter and presented her to the stranger. As soon as she was loaded on his kayak the elegant stranger paddled off into the frozen ocean with unnatural speed.
When Sedna came around to consciousness, she was in a great nest on top of a cliff. The only furnishings were dark feathers, fish bones, and a few clumps of skin and fur. The elegant stranger cackled and threw back his hood. He was none other than Raven, the capricious trickster deity who had arrived second in the world, soon after the creator had shaped it. Raven kept his beautiful stolen wife trapped in his nest and he fed her on fish (although she kept her ears open and listened to his magic words).
In the mean time, Sedna’s father became unhappy with the bargain he had struck. He set out on his kayak to find his daughter and rescue her from the mysterious suitor. Night and day he paddled, till finally he heard her cries for help intermingled with the howling winds.
Sedna’s father arrived while raven was off pursuing his other ventures, and Sedna quickly climbed down to his kayak so they could start back to the mainland. They paddled hard, but before they could reach land, Sedna spotted a distant pair of black wings in the sky. Raven had returned home to his nest and found his bride was missing. In anger at being cheated, Raven called out magic words of anger to the sea spirits. The winds rose to a gale and huge waves pounded the kayak.
Sedna's Bounty (Mayoreak Ashoona, 1993, lithograph)
Lost in terror, Sedna’s father cast his daughter into the ocean to placate Raven and the water spirits. Despite the storm and her father’s imprecations, she clung to the gunwale of the kayak. Then, in fury, her father pulled out his flint knife and hacked at her fingers. Sedna’s first finger came off and, amidst blood and saltwater, was transformed into narwhals and belugas. Her father hacked off her second finger which transformed into fur seals and ringed seals. Finally the knife cut through her third finger which transformed into the great walruses. Unable to grip the kayak with her maimed hand, Sedna fell into the sea. Rather than submit to her raven husband or her greedy father, she let herself sink beneath the waves down to the icy bottom of the ocean.
The Legend of Sedna (Sraiya, ca. 2010, pen and ink)
Beneath the waves she found Adlivun, the Inuit underworld where spirits are purified before they wander on to other worlds. With the help of her powerful new children she made herself ruler there. Her legs gradually changed into a mighty tail. Her humankind ebbed from her and was replaced by divine power and wrath. Sedna is still worshiped as the underworld god by Inuit peoples. She hates hunters both because of the wrongs she suffered at the hands of her father and because they continue to kill so many of her children—the seals, whales, and walruses. From time to time she raises a terrible storm to drown seafarers, or she gathers together all of the marine mammals within her long beautiful hair where the hunters can never find them. It is at such times that the shaman must travel down into Adlivun to beg with her and to praise her beauty and strength. Only then will she reluctantly let the storms abate and allow all of the marine mammals to go back to the coasts–where they are again in danger from Inuit spears.
Playful Sedna by artist Kakulu Sagiatok
The largest animal to ever exist is the blue whale (Balaenoptera musculus) an immense rorqual capable of growing to over 30 metres (100 ft) in length and 180 metric tons (200 tons) in mass. Although science has made substantial progress in understanding these great leviathans, the whales still harbor many secrets. However today’s post is not meant to be an overarching description of the giant mysterious creatures.
Image: National Geographic Channel ’s Kingdom of Blue Whale
Nor is this tiny post a comprehensive history. The blue whales have a story as big and long as they are, but, so far it has been a sad tale. Once their population numbered in the hundreds of thousands, however steel boats, exploding harpoons, and humankind’s inexorable appetite quickly winnowed them down to a few hundred in the 1970s. Today the blue whale population is estimated to number one percent of what it once was—and, although the population is slowly growing, the blue whales face competition for food (krill is industrially harvested as food for fish farms), changing global ocean currents, and death or serious bodily injury from shipping. A big container ship can kill a blue whale like an SUV crushing a toddler.
To sustain their immense bulk, blue whales must eat a prodigious amount of krill. A hungry adult whale can eat up to forty million of the tiny crustaceans per day (along with whatever copepods, squid, and fish are accidentally caught up along with the krill). The whales follow the huge pink underwater clouds of krill as they drift and twist through the oceans and thus circumstance (or crustacean whim) occasionally puts the blue giants in proximity to humans. When this happens the whales are a source of great wonder, but they are also in terrible danger from shipping.
Blue Whale Feeding on Krill Near the Surface (Barbara Howard, Acrylic on Canvas)
This is what is happening right now off Long Beach, California (the port complex of Los Angeles) which is the busiest port in the United States. The largest concentration of blue whales along the North America coast has gathered outside the port along the continental divide in order to hunt for krill. Marine biologists have been monitoring the whales with suction-mounted radio trackers which fall off after one day. Not only can the biologists radio warnings to ships coming close to the blue whales, they are also able to analyze the cetaceans’ behavior in order to better prevent accidents.
On October 7th, The LA Times reported that, “An 80-foot whale whose tag was scooped from the ocean Tuesday is a regular visitor that has been in the area for about a month. When researchers tagged the same whale a week before, they downloaded data that revealed a typical behavior pattern. The animal spent most of the day just outside the port, diving as deep as 1,000 feet. After dark, it stayed near the surface, perhaps to rest, and swam to the Santa Monica Bay.”
Lingering near the surface of the water beside the country’s busiest port after dark is dangerous behavior even for an 80 foot sea monster! Listen whales, everybody loves all-you-can-eat shrimp buffets (and everybody really loves to see blue whales) but you guys need to get out of LA. Take a clue from the fate of all the innocent teens hoping to break into the movie industry and move along before you get hurt. Blue whales can live to be 110 years old if they aren’t run over by ships filled with plastic crap from China!
Of course if you don’t think the whales will listen to my blog, it might be worth contacting your political leaders and asking for more comprehensive protection for ocean life.
