Cetaceans, the group of marine mammals that includes whales and dolphins, have demonstrated remarkable auditory and communicative abilities, as well as complex social behaviors. A new study published online November 27, 2006 in The Anatomical Record, the official journal of the American Association of Anatomists, compared a humpback whale brain with brains from several other cetacean species and found the presence of a certain type of neuron cell that is also found in humans. This suggests that certain cetaceans and hominids may have evolved side by side.

Although the biology of the humpback whale is well understood, there have been virtually no studies published on its brain composition, leaving an open question as to how brain structure may relate to the extensive behavioral and social abilities of this mammal. Although brain to body mass ratio, a rough measure of intelligence, is lower for baleen whales such as the humpback compared to toothed whales such as dolphins, the structure and large brain size of baleen whales suggests that they too have a complex and elaborate evolutionary history.

Patrick R. Hof and Estel Van der Gucht of the Department of Neuroscience at Mount Sinai School of Medicine in New York, NY, examined the brain of an adult humpback whale and compared it with the brain of a fin whale (another baleen species) and brains from several toothed whales, including three bottlenose dolphins, an Amazon river dolphin, a sperm whale, two beluga whales, a killer whale and several other whale and dolphin species. They found that the humpback cerebral cortex, the part of the brain where thought processes take place, was similar in complexity to smaller sized cetaceans such as dolphins. The large area of cortex found in these mammals is thought to be related to acoustic capabilities and the current study shows that it is organized into a system of core and belt regions. However, substantial variability was found between the cell structure of the cortex in humpbacks compared to toothed whales. The authors suggest that these differences may indicate differences in brain function and behavior in aquatic species that are not yet understood.

One feature that stood out in the humpback whale brain was the modular organization of certain cells into “islands” in the cerebral cortex that is also seen in the fin whale and other types of mammals. The authors speculate that this structural feature may have evolved in order to promote fast and efficient communication between neurons. The other notable feature was the presence of spindle cells in the humpback cortex in areas comparable to hominids and in other areas of the whale brain as well. Although the function of spindle neurons is not well understood, they are thought to be involved in cognitive processes and are affected by Alzheimer’s disease and other debilitating brain disorders such as autism and schizophrenia. Spindle neurons were also found in the same location in toothed whales with the largest brains, which suggests that they may be related to brain size.

The authors note that spindle neurons probably first appeared in the common ancestor of hominids about 15 million years ago, since they are observed in great apes and humans, but not in lesser apes and other primates; in cetaceans they evolved earlier, possibly as early as 30 million years ago. It is possible that they were present in the ancestors of all cetaceans, but were retained only in those with the largest brains during their evolution. It may also be that they evolved several times independently in the two cetacean suborders; part of this process may have taken place at the same time as they appeared in the ancestor of great apes, which would be a rare case of parallel evolution.

“In spite of the relative scarcity of information on many cetacean species, it is important to note in this context that sperm whales, killer whales, and certainly humpback whales, exhibit complex social patterns that included intricate communication skills, coalition-formation, cooperation, cultural transmission and tool usage,” the authors state. “It is thus likely that some of these abilities are related to comparable histologic complexity in brain organization in cetaceans and in hominids.”

The authors conclude: “Cetacean and primate brains may be considered as evolutionary alternatives in neurobiological complexity and as such, it would be compelling to investigate how many convergent cognitive and behavioral features result from largely dissimilar neocortical organization between the two orders.” They also suggest that the current study provides a framework for further investigations into the brain and behavior of cetaceans, which are naturally elusive, poorly documented and often endangered.

Source: http://www.sciencedaily.com/ - Article: “The Structure of the Cerebral Cortex of the Humpback Whale, Megaptera novaeangliae (Cetacea, Mysticeti, Balaenopteridae),” Patrick R. Hof, Estel Van der Gucht, The Anatomical Record, Published Online: November 27, 2006. (DOI: 10.1002/ar.a.20407).

A new study has revealed that humpback whales are capable of emanating as many as 622 social sounds.

Scientists believe the whales’ broad vocal repertoire enables them to communicate with their fellow whales, like summoning their young or even wooing potential mates by expressing emotions.

Rebecca Dunlop, a researcher in the School of Veterinary Sciences at the University of Queensland, Australia said that while some sounds are brief, some are unpatterned, distinct from lengthier, complex whale songs.

She said the study threw new light on the fact that whales convey more meaning through vocalizations than previously thought.

“I wouldn’t say (whales possess) language, as that’s a human term. Whales don’t string these sounds together like words and form sentences. It’s more like a simple vocabulary,” Discovery News quoted Rebecca as saying.

For their study, the team used a static hydrophone array - sensitive equipment that detects sound waves - to visually track 60 pods of whales migrating along the east coast of Australia.

The waves linked the whale sounds to various activities and contexts.

The team identified 622 distinct sounds, which fell into 35 basic types.

Rebecca said these included “wops” made by females, “thwops” made by males, “yaps” made when pods split, and high pitched cries that appeared to express anger.

In addition to vocalizations, the team also found that whales sent messages through body language - by breaching the surface, slapping water with their tails and blowing underwater bubbles.

She said the whales also sometimes even “speak” short song units individually instead of singing them. Males especially seem to do this when trying to woo a female.

“Song is a loud broadcast signal and two singers singing at the same time is bound to be confusing to the receiver. If he’s trying to attract a female, but doesn’t want his signal confused with another singer in the area, then using song units in this case might be the way forward,” Rebecca said.

The study will be presented at the upcoming joint meetings of the Acoustical Society of America (ASA) and the Acoustical Society of Japan in Hawaii.

Source: http://www.underwatertimes.com/

 

It is one of the fastest growing areas of so-called eco-tourism, a supposedly environmentally-friendly way to get close to nature enjoyed by more than 11 million people.

But research has found that whale-watching may be responsible for damaging changes in the mammals’ behaviour and could be putting them off feeding. A study of killer whales by researchers from the University of St Andrews in Scotland and Dalhousie University in Halifax, Nova Scotia, Canada, has revealed that the approach of boats disturbed the animals to such an extent that they decreased their food intake by up to 18 per cent.

Whale-watching is claimed to be a way of raising awareness of the giant mammals while providing an alternative source of income for communities that traditionally hunted them.

Such eco-tourism is worth more than £1 billion. In Britain alone, about 100 companies offer whale-watching trips from Cornwall, Wales and the west coast of Scotland. Rob Williams, a sea mammal researcher from St Andrews based on Pearse Island, British Columbia, who led the killer whale research, said that although all boat traffic within an average of 3 sq mi (5 sq km) disturbed the whales’ behaviour, whale-watching boats were the only vessels that actively searched for the mammals.

“The most contentious example of human disturbance may be commercial whale-watching operators,” said Mr Williams. “The exponential increase in commercial whale-watching activity has caused some to question the benign nature of that industry.

“This study provides indirect evidence that feeding activity is disrupted by the presence of boats, which could lead to a substantial decrease in energy-gain opportunities. Overall, whales reduced their time spent feeding from 13 per cent to 10 per cent when boats were present. They showed not only a lower probability of continuing feeding, but also a lower probability of initiating a feeding bout.”

The study on killer whales off the coast of British Columbia over seven years revealed that pods were more likely to attempt to distance themselves from the boats when they came into the same area and stop social behaviour.

Conservation groups believe that the effects of whale-watching boats on killer whales also apply to other whale populations. They fear that dwindling food stocks are forcing whales to spend more time searching for food and, if they are frightened away from a good feeding spot by whale-watching activity, they become weaker and could even starve.

They are now calling for whale-watching companies to be issued permits before they can carry out trips and want designated routes to prevent whales from being chased.

Vanessa Williams-Grey, the head of the responsible whale-watching programme at the Whale and Dolphin Conservation Society, said: “Researchers over the last few years are starting to notice whale populations being displaced from favourite feeding or resting areas by the presence of too many vessels.”

Many countries, including Britain, protect whales under wildlife legislation but it is hard to regulate and enforce.

Mark Henrys, who runs Northern Light Charters, a sealife cruise company on the Isle of Mull on the west coast of Scotland, admitted that he was concerned by the behaviour of some of his fellow operators.

“You get boats on daytrips radioing each other to report a sighting and a stream of boats turning up in an area,” he said. “That is where you get a harder impact on the whales and dolphins. I think it is very credible what this research is saying.”

Sourc: http://www.telegraph.co.uk/

TUKTOYAKTUK, N.W.T.  — Arctic hunters were reluctantly gathering harpoons and rifles Wednesday to kill beluga whales that have been trapped for weeks in saltwater lakes and now have only one small air hole remaining.

Although people near Tuktoyaktuk, N.W.T., had hoped the dozens of belugas would find their way back to the Beaufort Sea before ice blocked the way out, many didn’t make it, so hunters were planning to move in Thursday.

“We’re going to have people go out to the site and harvest as many as we can,'’ said Paul Voudrach, head of the Tuktoyaktuk hunters and trappers committee and local representative of the territorial government’s Environment Department.

About 200 beluga were first spotted in early August by hunters in the Husky Lakes area south of Tuktoyaktuk, a string of saltwater inlets which are linked to the ocean through a 100-metre-wide channel. There were still about 80 of the white, station-wagon-sized mammals left in the lakes by late October, but by then the lakes and the channel were quickly freezing over and the whales’ airhole shrinking.

Residents were cheering for the belugas to escape, despite the fact each animal could provide enough meat and muktuk — skin and blubber usually served raw — to last a couple of large families through the winter.

But a storm last weekend froze the channel solid and left the whales with a single breathing hole about the area of a one-bedroom apartment, shrinking inexorably in the Arctic cold.

“(Escape) is quite impossible now,'’ said Chuck Gruben, leader of the hunt.

Killing the whales now while they’re still in good shape is better than leaving them to slowly freeze under the ice, said Voudrach.

“(People) don’t like seeing animals suffer. Right now we’re looking to take all of them that we can.'’

Voudrach said such occurrences happen from time to time and are part of the natural cycle.

It’s hard to know how many whales are left.

“What I saw … in the hole I counted 10 at once,'’ Gruben said. “But who’s to say — there might be 10 more underneath. The only time we’ll find out is when we start pulling them out of the water.'’

Hunters will gather around the breathing hole and wait for the belugas to surface for air.

“Sooner or later they’re going to have to come up in that one hole,'’ Gruben said. “All the other breathing holes are frozen over.'’

One man will harpoon the animal and another will shoot it with a rifle. Six others will be on hand to haul the whales out of the water.

They will be butchered right there on the ice and the meat and muktuk distributed to area communities.

Although most hunters got enough whale meat during this summer’s hunting season, some could still use more, said Gruben.

“You just look at it as food on the table. If we just leave them there, they’re going to freeze and that’s not only a waste of an animal, it’s a waste of food.

“The people will be glad to get that muktuk.'’
Source: http://www.ctv.ca

Beaked Whales Perform Extreme Dives To Hunt Deepwater Prey

A study of ten beaked whales of two poorly understood species shows their foraging dives are deeper and longer than those reported for any other air-breathing species.  This extreme deep-diving behavior is of particular interest since beaked whales stranded during naval sonar exercises have been reported to have symptoms of decompression sickness. One goal of the study was to explore whether the extreme diving behavior of beaked whales puts them at a special risk from naval sonar exercises.

Scientists from the Woods Hole Oceanographic Institution (WHOI) teamed with colleagues from the University of La Laguna in Spain, the University of Aarhus in Denmark, Bluwest and the NATO Undersea Research Centre in Italy. The team studied Cuvier’s beaked whales (Ziphius cavirostris) and Blainville’s beaked whales (Mesoplodon densirostris) in Italian and Spanish waters using a non-invasive digital archival tag or D-tag developed at WHOI by one of the authors, engineer Dr. Mark Johnson.  Their findings are reported in the current online issue of the Journal of Experimental Biology.

The D-tag, about the size of a sandal,  has a variety of sensors to record sounds and movements, and is attached to the animals with four small suction cups using a handheld pole. It is programmed to release from the animal within a day and is recovered with help from a VHF radio beacon in the tag. The 3-6 Gbytes of audio and sensor data are then off-loaded to a computer for anaylsis.

Dr. Peter Tyack, a senior scientist in the WHOI Biology Department and lead author of the study, says they found some similarities with the much better studied sperm whales and elephant seals, but also some major differences. “These two beaked whale species make long, very deep dives to find food, and then make shallow dives and rest near the surface. By contrast, sperm whales and elephant seals can make a series of deep dives without the need for prolonged intervals between deep dives. We think that beaked whales return to the surface after deep dives with an oxygen debt and need to recover before their next deep dive.”

Tyack said the team’s analysis suggests that the normal deep diving behavior of beaked whales does not pose a decompression risk. “Rather, it appears that their greatest risk of decompression sickness would stem from an atypical behavioral response involving repeated dives at depths between 30 and 80 meters (roughly100 to 250 feet),” Tyack said. “The reason for this is that once the lungs have collapsed under pressure, gas does not diffuse from the lungs into the blood. Lung collapse is thought to occur shallower than 100 meters (330 feet), so deeper parts of the dive do not increase the risk of decompression problems. However, if beaked whales responded to sonars with repeated dives to near 50 meters (165 feet), this could pose a risk.â€�

The Cuvier’s beaked whales were tagged in June 2003 and 2004 in the Ligurian Sea off Italy, while the Blainville’s beaked whales were tagged in October 2003 and 2004 off the island of El Hierro in the Canary Islands. Both field sites were in deep water, between 700 and 2,000 meters (2,300 to 6,500 feet) with steep bottom topography. Tags were attached to seven Cuvier’s beaked whales and three Blainville’s beaked whales, and they remained attached to the whales for an average of 8 hours and 12 hours, respectively.

 “Although this study was limited to ten animals, it provides the first detailed information available about the diving, acoustic, and movement behavior of two species of beaked whales,� Tyack said. “Shallow dives seem to be performed between deep dives, and both species dive very deep to hunt for prey. They seem to spend equal time ascending and descending in shallow dives, but take longer to ascend from deep dives.�

The slow ascent from deep dives is a major mystery. “Why don’t they stay longer at depth to feed, and then come up more rapidly?� Tyack said.  “Avoidance of decompression problems by slow ascent, as in scuba divers, cannot account for this behavior if the lungs of these breathhold diving marine mammals are collapsed at depths greater than 100 meters (330 feet).�

Very little is known about these two species of beaked whales since they spend little time on the surface and it is difficult to tag them.  The much better studied sperm whale can dive for more than one hour to depths greater than 1,200 meters (roughly 4,000 feet), but typically dives for 45 minutes to depths of 600-1,000 meters (1,968 to 3,280 feet). Elephant seals, another well known deep diver, can spend up to two hours in depths over 1,500 meters (nearly 5,000 feet), but typically dive for only 25-30 minutes to depths of about 500 meters (1,640 feet).  Marine mammals seem to have adapted to the effects of diving deep and optimizing their oxygen supplies.

The Cuvier’s beaked whales dove to maximum depths of nearly 1,900 meters (about 6,230 feet) with a maximum duration of 85 minutes, while the Blainville’s beaked whales dove to a maximum depth of 1,250 meters (4,100 feet) and 57 minutes in duration. The dives near 1,900 meters constitute the deepest confirmed dives reported from any air-breathing animal. While people often focus on the maximum dives of breathhold diving animals, breathhold divers are not at a track meet and it is the average of the deep foraging dives that is more important. Regular echolocation clicks and buzzes and echoes of what appears to be prey were recorded on the tags, suggesting the whales were hunting for food on the deep dives. The average foraging dive for Cuvier’s beaked whale went to a depth of 1,070 meters (about 3,500 feet) with a duration of 58 minutes, while the Blainville’s beaked whales dove to an average depth of 835 meters (2,740 feet) and 46.5 minutes in duration.  These represent the deepest and longest average dives reported for any breathhold-diving animal.

These two beaked whale species have been reported to mass strand during naval sonar exercises in the area.  It is unclear how these beaked whale species respond to the sonar sounds and whether their responses cause physiological changes that increase the risk that  they will strand and die.  This study suggests the paradoxical result that even though beaked whales are extreme divers, their normal diving behavior does not seem to put them at greater physiological risk for sonar exposure. Rather it suggests that physiological risk would stem from a specific behavioral response to the sonars.

“No matter what the precise cause of the strandings is, we need to develop effective mitigation strategies to reduce the accidental exposure of beaked whales to bay sonar,� Tyack said. “The information in this study provides critical data to design efficient acoustic and visual detection methods for these at-risk species of marine mammals.�

Funding for the tag development was provided by a Cecil H. and Ida M. Green Technology Innovation Award at WHOI and the U.S. Office of Naval Research. Funding for field work was provided by the Strategic Environmental Research and Development Program  (SERDP), the National Ocean Partnership Program, the Packard Foundation, the Canary Islands Government, and the Spanish Ministry of Defense. Fieldwork support was provided by BluWest, NATO Undersea Research Center, and the Government of El Hierro.
Source: http://www.sciencedaily.com/releases/2006/10/061019192417.htm

 

Oslo - Norwegian hunters killed 546 minke whales this year, falling far short of their commercial whaling quota because bad weather spoilt much of the season, government and industry officials said on Monday.

Norway resumed commercial hunts of minke whales in 1993 despite an international moratorium, and raised its quota in 2006 to 1 052, the highest in two decades.

But hunters only managed to reach just over half that amount in the season that ended last month - 93 fewer than last year, officials said.

“To hunt whales you need very good weather, which we didn’t have,” said Magnar Pedersen, of the Norwegian Raw Fish Organisation. He added that the Norwegian whaling fleet was not adapted well enough to the rough conditions in Arctic waters.

Norwegian Directorate of Fisheries spokesman Olav Lekve said next year’s quota had not been set yet.

Norwegians eat the red meat of whales, but the blubber - once the most valuable part of the catch - is now dumped because there is no domestic market for the fatty tissue.

Anti-whaling activists have warned that the Norwegian hunt could encourage other countries including Russia to break the moratorium on commercial whaling that took effect in 1986.

Iceland last month resumed commercial whaling, and said it would issue licenses to kill nine fin whales and 30 of the more numerous minke whales.

Source: Sapa-AP - http://www.iol.co.za/index.php?set_id=14&click_id=143&art_id=qw116345214417B256

MADRID, Spain: A 2-week-old beluga whale — the first born in captivity in Europe — may not survive because his mother has stopped producing milk, officials at a marine park in southeastern Spain said Thursday.

Officials at the Valencia aquarium said the baby beluga had suffered from an irregular swimming style and excessive buoyancy since his Nov. 2 birth.

The beluga’s 8-year-old mother, Yuka, is the youngest whale to give birth in captivity. She conceived naturally, which is also unusual, and her pregnancy was a long 16 months.

Because of her inexperience, Yuka was unable to nurse her infant and stopped producing milk — despite efforts by aquarium staff to pump milk from her mammary glands, said Pablo Areitio, director of biology, and Daniel Garcia, chief veterinarian at the marine park.

quarium staff have been nursing the young whale with a formula that includes antibiotic and anti-fungal agents to help ward off infection, Areitio and Garcia told reporters Thursday.

The baby whale’s struggling health is likely due to Yuka’s inability to nurse and an unusually long labor, they said.

Areitio said aquarium staff had contacted marine experts in Vancouver, Connecticut and New York, who warned of the “enormous difficulty of raising animals under these circumstances.”

Of several similar cases, only one young whale survived — only after it began suckling again, Areitio said, noting that aquarium staff members were trying to stimulate Yuka’s mammary glands so she would begin producing milk again.

The baby whale has not yet been named, officials said.

It is slowly gaining weight, however, and his swimming is improving, they said.

Source: http://www.iht.com/articles/ap/2006/11/16/europe/EU_GEN_Spain_Baby_Beluga.php

FREDERICTON (CP) - A number of rare and endangered North Atlantic right whales are overstaying their welcome in the Bay of Fundy and could force a delay in the opening of lobster season. Jerry Conway of the Department of Fisheries and Oceans said Friday that although the main pods left the bay on schedule for southern waters, as many as 50 of the slow-moving whales are hanging around.

Fishermen are scheduled to start setting traps on Tuesday.

“The concern is that with this number of whales and the opening of the lobster season next week, there is potential for right whales to get entangled in fishing gear,” Conway said.

He said normally, right whales leave the Bay of Fundy by mid-October, moving first into the Gulf of Maine before heading further south.

Officials are discussing with fishermen the possibility of delaying the opening of the lobster season. But Conway said other, less drastic measures are also being considered.

Conway said the department will put on extra patrols to monitor the movement of the whales. He said it may be possible to simply advise fishermen of the location of the whales so they can avoid setting lobster traps in those areas.

The whales have been spotted frolicking and lolling on the surface along the southern New Brunswick coast, said Conway, adding that they are so close to shore, people have been able to watch them from the shoreline.

Conway said the whales have plenty of food and clearly feel there’s no need to rush south.

“Why leave when there’s lots to eat,” he said.

Fishermen in southern New Brunswick believe government officials are overreacting to the situation.

“I’m a pilot and I’ve been flying the Bay of Fundy on a daily basis since 1978 and I can tell you this is not news,” said Klaus Sonnenberg of the Grand Manan Fishermen’s Association.

“It’s normal to see right whales lingering in the Bay at this time of the year.”

Sonnenberg said more than 1,000 fishing families depend on the lucrative Bay of Fundy lobster fishery for income.

Fishermen also don’t believe there are as many as 50 right whales left in the bay, he said, because normally just a couple of family groups linger a bit longer than the others.

“We’ve never had any problem.”

Sonnenberg said recently appointed managers at the Fisheries Department appear unaware of the typical situation.

“There seems to be an overreaction by the Canadian Department of Fisheries and Oceans,” he said.

“I think there is a lack of understanding by DFO as to what the normal situation is.”

Sonnenberg said U.S. fishermen fish lobster year round in the Gulf of Maine, and they have never closed their fishery to guarantee safe passage for the whales.

The North Atlantic right whale was hunted to near extinction by the late 1800s.

Although it is now a protected species, marine biologists estimate the total population of North Atlantic right whales at no more than 350, of which about 80 are breeding females.

The whales frequent the coastal waters from Florida to the Maritimes, areas that are heavily used by the fishing and shipping industries.

The whales’ low reproductive rate coupled with a declining survival rate, especially for breeding females, appears to have prevented the population from recovering.

The population is estimated to be declining at a rate of two per cent a year.

Source: http://www.cbc.ca

ATLANTA - Scientists on Thursday took their closest look ever at one of the world’s biggest fish - with the help of about 50 staffers, a stretcher that could hold a small bus and a hose pumping liquid anesthetic out of two 300-gallon vats.The daybreak examination of Ralph, a 22-foot male who is one of four whale sharks at the Georgia Aquarium, was part of a groundbreaking series of exams on some of the world’s largest fish at the only place outside of Asia where the sharks are on display.

Researchers hope the study will provide new information about an animal that has remained largely a mystery to scientists, despite its massive size and wide-ranging habitat.

“There are huge unknowns out there,” said Ray Davis, vice president of zoological operations at the aquarium. “They’re the largest fish in the ocean and we have the least information about them.”

Ralph and Norton, the aquarium’s other male whale shark, arrived last June from Taipei, Taiwan, where they had been destined to become seafood. They were joined a year later by two females, Alice and Trixie, in their 6 million gallon tank.

Thursday’s poking and prodding session was the latest in a series of exams on the four fish that began in October.

They were given basic exams when they arrived at the aquarium, but the logistics of transporting the giant sharks made it difficult to study them in any great detail, Davis said.

It was Ralph’s third exam. Norton has been examined twice and Alice and Trixie once each.

Around 6 a.m. Thursday, a team of 20 divers used nets to guide the shark into a massive stretcher that hung near the water’s surface from an industrial-sized gantry.

There, a hose pumped a liquid anesthetic into the water around Ralph’s head - making him nearly unconscious for the two-hour checkup.

Once he was under, veterinarians from the aquarium and Mote Marine Laboratory in Sarasota, Fla., took blood samples to test the adolescent shark’s hormone levels and studied the inside of his mouth and gills to learn more about how he digests food. They took DNA samples and used an ultrasound machine, with a small, portable computer screen, to check on his internal organs. They also measured him to track his growth.

At 22 feet, Ralph is still the equivalent of a teenager. Adult male whale sharks can grow up to 50 feet long.

The data will be shared with scientists around the world, including staff at Kaiyukan Aquarium, in Osaka, Japan, which also has a whale shark but does not conduct the same level of scientific study, according to Georgia Aquarium officials.

“So little is known about them,” said aquarium director Jeff Swanagan. “Every time we answer a question, we come up with 25 more questions.”

While Alice and Trixie remained out of sight during the exam, an apparently curious Norton swam within a few feet of the stretcher several times. Once, his tail bumped the netting around the stretcher where several researchers were standing.

At the end of the 2-hour exam, Ralph swam smoothly out of the stretcher, with a team of divers again surrounding him to make sure the effects of the anesthetic had worn off.

More than 3 million people have visited the Georgia Aquarium since it opened last November - far outpacing attendance predictions.

Bankrolled almost exclusively by Home Depot Inc. co-founder Bernie Marcus, the aquarium is considered the world’s largest, with roughly 100,000 fish and more than 8 million gallons of water.

ON THE NET

Georgia Aquarium, http://www.georgiaaquarium.org

Oslo - A ferocious-looking fossil with sharp teeth found in Australia shows that ancestors of today’s toothless blue whales were not all “gentle giants”, a report said on Wednesday.

The 25-million-year-old fossil is of an early type of baleen whale, a group including modern humpback whales, minke whales and blue whales that feed via baleen, comb-like plates in their mouths that filter plankton from sea water.

“This bizarre, new baleen whale did not even have baleen,” Erich Fitzgerald, of Monash University in Australia, said of the small whale that was probably up to 3.5m long.

“It had teeth and was a powerful predator that captured large fish, perhaps sharks, maybe even other whales,” he told Reuters.

“Some of the early baleen whales weren’t gentle giants.”

Most scientists have believed that baleen whales quickly evolved baleen for feeding on tiny fish and plankton after breaking from a common ancestor with toothed whales almost 40-million years ago.

Modern toothed whales include dolphins, killer whales and sperm whales - the species made famous as the bane of Captain Ahab in Herman Melville’s Moby Dick.

“This rewrites the picture of baleen whale evolution,” Fitzgerald said. The fossil was found near Jan Juc, a town in Victoria, south-eastern Australia, and dubbed “Janjucetus”.

Its sharp teeth were about 3cm long and it also had large eyes, apparently suited for hunting, according to Fitzgerald’s report, published in the journal Proceedings of the Royal Society B.

Blue whales, which can exceed 150 tons and grow longer than 30m, are the largest creatures ever to inhabit the earth - bigger than any dinosaur. Whales evolved from land mammals, where their closest relative is the hippopotamus.

Source: http://www.int.iol.co.za/