Classification of Cetaceans

There are about 86 species of whales, dolphins and porpoises in the order Cetaceans, divided into two sub-orders:

Toothed whales or Odontoceti:

have teeth and a single blowhole. The number of teeth varies by species; it ranges from 2 (in some beaked whales) to 250 (some dolphins). They are smaller than baleen whales. Many species live in pods. Toothed whales have well-developed echolocation that they use to locate food (fish, squid, marine mammals, etc.) and other whales. Toothed whales have asymmetrical skulls.

Baleen whales or Mysticeti:

are larger than the toothed whales and are among the largest animals on earth.They have baleen plates instead of teeth, which are used to filter tiny organisms, like krill and small fish from the water. They use their tongue to dislodge the food from the baleen and swallow it. Baleen is made of keratin, the same protein that our hair and nails are made of. Baleen whales have 2 blowholes.

BALEEN WHALES:

Blue whales

Blue whales are rorquals (family Balaenopteridae), a family that includes the Humpback whale, the Fin whale, Bryde’s whale, the Sei whale, and the Minke whale.

Blue Whales are the largest animal in existence and the heaviest known to have existed, even bigger than any of the dinosaurs.

These huge whales can measure up to 30 metres (98 ft) and weigh about 190 tons (172365 kg). Long and slender, the blue whale’s body can be various shades of bluish-grey dorsally and somewhat lighter underneath. In addition to the blue whale’s massive size it is also one of the loudest animals in existence. In fact a blue whale’s call can be heard several miles away and far below the ocean’s surface. Blue whales are solitary animals often travelling alone or in small groups.

They eat krill and small fish. An adult blue whale can eat up to 40 million krill in a day. Because krill move, blue whales typically feed at depths of more than 100 metres (330 ft) during the day and only surface-feed at night.

Commercial and excessive hunting is a threat and Blue whales are an endangered species.

 

Bowhead whales

Today the bowhead whale has several other names including the Greenland right whale, Arctic whale, steeple-top and Russian whale.The bowhead whale is a species of the right whale family Balaenidae, in suborder Mysticeti and genus Balaena. A stocky dark-colour whale without a dorsal fin, it can grow to 20 m (66 ft) in length. This thick-bodied species can weigh 75 to 100 tonnes. It lives entirely in fertile Arctic and sub-Arctic waters, unlike other whales that migrate to low latitude waters to feed or reproduce. Studies show that they can live between 100 -200 years, making them the longest living mammal known. The bowhead has the largest mouth of any animal and contains a baleen of 3 meters.

The bowhead whale has paired blowholes that spout a blow 20 feet (6m) high. Its blubber is the thickest of any animal, averaging 43–50 cm (17–20 in).

The bowhead has a massive bony skull which it uses to break through the Arctic ice to breathe. Inuit (Arctic Eskimo) hunters have reported them surfacing through 60 cm (24 in) of ice. Like right whales, it swims slowly, and floats after death, making it ideal for whaling!

The bowhead is listed in Appendix I by CITES (that is, “threatened with extinction”especially in Svalbard population (Critically endangered))

 

Fin whales

Fin whales are also called the razorback which is a common nickname. Measuring up to 90 feet (27.4m) long they are considered the second biggest whale in existence in terms of length right after the blue whale. Despite its large size this whale is relatively slender and streamlined allowing it to reach speeds of over 25 miles (40.2km) per hour for short periods of time. The head appears almost v shaped and is flat on top and the dorsal fin is curved in shape resting near the back-end of the whale. Its flippers are small in size and tapered when compared to other whales.

Commercial whaling, climate and environmental change, loss of habitat and toxics are great threats for Fin whales like for all cetaceans. Despite the fact that Fin whales are endangered, Iceland still continues killing Fin whales, selling the majority of meat to Japan.

 

Humpback whales

The Humpback Whale is one of the most recognized of them all due to the hump over the dorsal fin. They have five meter long flippers that are almost one third of their body length. They have an average size of 52 feet (15.8m) long.There is quite a difference in their sizes when it comes to weight, depending on location. Those that live in cooler regions can be up to 40 tons whiles those in the tropical areas are about 30 tons. The Humpback Whale has a more detailed feeding system than any other whale. It features grooves on the throat that allow it to open up and to expand when they eat. This way they can take in huge amounts of water. The filtering system keeps the food and pushes the water out.

Humpbacks behaviour includes acrobatic leaping out of the water, slapping of its fins, flukes on the water and magical songs, and travel for great distances through the world’s oceans. Humpback whales eat mostly krill, plankton, and herring. They are powerful swimmers, and they use their massive tail fin, called a fluke, to propel themselves through the water and sometimes completely out of it. These whales, like others, regularly leap from the water, landing with a tremendous splash.

Humpback whales are a protected species.

 

Gray whales

The Gray Whale is one that people seem to be able to identify when they are looking into the ocean. They have some characteristics that make them quite familiar like the gray patches and white mottling on its dark skin. Gray whales are often covered with parasites and other organisms that make their snouts and backs look like a crusty ocean rock. The gray whale is a baleen whale that migrates between feeding and breeding grounds yearly. The gray whales travels in groups called pods, some of these giants swim 12,430 miles (20,000 km) round-trip from their summer place in Alaskan waters to the warmer waters off the Mexican coast.

It reaches a length of 14.9 meters (49 ft), a weight of 36 tonnes (40 short tons), and lives between 55 and 70 years. They have two blowholes on top of their head, which can create a distinctive V-shaped blow at the surface in calm wind conditions.

 

Right whales

They are classified in the family Balaenidae with the bowhead whale. Right whales have rotund bodies with arching rostrums, V-shaped blowholes and dark gray or black skin. The most distinguishing feature of a right whale is the rough patches of skin on its head which appear white due to parasitism by whale lice. There is no denying the sheer size of the Right Whale. They can weigh up to 100 tons (90718kg) as well as be up to 60 feet (18.2m) long, significantly larger than other coastal species such as Humpbacks, Grays, or Bryde’s, but smaller than Blues.

Right whales are a preferred target for whalers because of their docile nature, their slow surface-skimming feeding behaviours, their tendencies to stay close to the coast, and their highblubber content (which makes them float when they are killed, and which produce high yields of whale oil) Right whales were so named because early whalers considered them the “right” whale to hunt!?

 

Minke whales

The minke whales are the second smallest baleen whale; only thepygmy right whale is smaller. It has a huge head, up to one quarter of the length of its body. Minke whales grow to be about 25-30 feet (7.8-9 m) long, weighing about 6-7.5 tons (5.4-6.8 tonnes). The largest Minke whale reported was 9.5 tons and 30 feet (9 m) long.

The two recognised species are the Antarctic Minke and the common Minke, of which the dwarf Minke is a subspecies.

Minke whales make very loud sounds, up to 152 decibels (as loud as a jet taking off). They have a life expectancy of over 20 years and common Minke are found in oceans all over the world.

They prefer cooler temperatures, are frequently seen in coastal and inshore waters and are less common in tropical waters.

By the early 1970s, following the overhunting of larger whales such as the Sei, Fin, and Blue whales, Minke became a more attractive target of whalers. Although Norway initially followed the moratorium, they had placed an objection to it with the IWC and resumed a commercial hunt of the Common Minke whale in 1993. Quotas are renewed every year and they keep the hunt as a tradition!?

 

Sei Whales

The Sei whale is a baleen whale, the fourth-largest rorqual after the blue whale, the fin whale and the humpback whale.

The Sei whale is one of the fastest cetaceans, reaching speeds of up to 50 km per hour. They are often seen in groups of two to five.

When the Sei whale is swimming the blowholes and dorsal fins are visible at the same time. Sei whales are found in nearly all waters of the world, including the sub-Arctic and sub-Antarctic where they go for summer feeding, but not in the Mediterranean or Baltic seas.

Like other great whales, the Sei whale prefers to spend the summer feeding in the cooler northern waters before migrating south to warmer waters to breed and calve. Sei whales can live for 65 years; their size ranges from 14 to 20 m long and their weight is about 20 tons.

Sei whales are classified as Endangered (IUCN 2008) as populations are severely depleted by the commercial whaling industry.

 

TOOTHED WHALES:

Killer whales or Orcas

Also referred to as the Blackfish or Grampus.

The killer toothed whale is one of 35 species in the oceanic dolphin family and the largest member. It first appeared about 11 million years ago. There are 4 types of Killer whales and they can be found from the Polar Regions to the Equator. Orcas are toothed and powerful whales, weigh about 8,000 – 12,000 pounds (3600-5400 kg) and eat fish, squid, and marine mammals. They live in small pods and grow to be about 27 feet long (8 m). The lifespan averages 50 years, with a maximum of 90 years.

While kept in captivity life expectancy can be reduced by as much as 2/3, causing many of them to live only until their 20’s!

Killer whales or Orcas have the second-heaviest brains among marine mammals (after sperm whales, which have the largest brain of any animal) and described as being intelligent.

Some local populations are considered threatened or endangered due to prey depletion, habitat loss, pollution capture for marine mammal parks, and conflicts with fisheries. Killer whales have good eyesight above and below the water, excellent hearing, and a good sense of touch. They are notable for their complex societies. Only elephants and higher primates, such as humans, live in comparably complex social structures. Due to orcas’ complex social bonds and society, many marine experts have concerns about keeping these animals in captive situations! Killer whales needs, like all marine mammals, their space and freedom. They are friendly, sociable and can only become aggressive due to isolation, stress and threats.

 

Beluga whales or the white whales

The Beluga Whale is often called the white whale due to its colour. It has a formation to its head referred to as a melon which sticks out and it is one of the smallest whales within the cetacean species. It is also referred to as the melon head or as the sea canary due to its high-pitched twitter. The beluga is able to change the shape of its head by blowing air around its sinuses to focus the emitted sounds.

Beluga whales are very social marine animals foraging and socializing in both small and large pods. They live in frigid arctic and subarctic waters, but many migrate to warmer water in the summer. These whales can generally be seen communicating with one another using a series of high pitched clicks and whistles.Like other toothed whales the beluga whale uses echolocation to search for food and navigate the ocean.

It can hear sounds within the range of 1.2 to 120 kHz, with the greatest sensitivity between 10 and 75 kHz, where the average hearing range for humans is 0.02 to 20 kHz. Their vision is relatively poor when compared to dolphins. The beluga’s body size is up to 5.5 m (18 ft) long and weighing up to 1,600 kg (3,500 lb).

Commercial whaling is reducing the numbers of Beluga whales worldwide.

 

Narwhales

Also called the Unicorn of the sea.

Like the beluga, Narwhals are medium-sized toothed whales. They have a large “tusk” from a protruding canine tooth. Their tusks grow throughout life, reaching lengths up to 3.1 m (10ft 2 in). It is hollow and weighs around 10 kg (22 lb).

They live year-round in the Arctic waters in small pods of 5-10.

The total body size can range from 3.95 to 5.5 metres and the average weight of an adult Narwhale is 800 to 1,600 kilograms.

Found primarily in Canadian Arctic, Greenlandic and Russian waters, the narwhal is a uniquely specialized Arctic predator. In winter, it feeds on benthic prey, mostly flatfish, under dense pack ice. During the summer, narwhals mostly eat Arctic cod and Greenland halibut. When in their wintering waters, narwhals make some of the deepest dives recorded for a marine mammal, diving to at least 800 metres (2,600 feet) over 15 times per day, with many dives reaching 1,500 metres (4,900 feet) and staying at the bottom for around 25 minutes.

They can live up to 50 years but are often killed by suffocation or starvation when the sea ice freezes over. The Narwhale is threatened as the hunt for their meat and ivory continues!

 

Sperm whales

The Sperm Whale is gray in colour, large teeth, one blowhole and many people immediately think of the story of Moby Dick when they see one. The sperm whale’s unique body is unlikely to be confused with any other species.

The sperm whale’s distinctive shape comes from its very large, block-shaped head, which can be one-quarter to one-third of its length.

Adult males grow to be about 50-60 feet (17-20 m) long, and weigh about 40-50 tons (females about 15-20 tons and 33-40 feet long)

It has the largest brain of any animal on Earth, more than five times heavier than a human’s.

The sperm whale’s clicking vocalization, a form of echolocation and communication, may be as loud as 230 decibels underwater, making it the loudest sound produced by any animal.

Sperm whales can live for more than 60 years. The sperm whale can be found anywhere in the open ocean.

It is the deepest diving whale; it can dive down to more than 4.000 feet (1.200 m) and hold its breath for about an hour.They are bottom feeders that eat squid, fish, octopus, eels, etc. The sperm whale is an endangered species.

 

The beaked whales

The beaked whales are one of the most specialised of all the mammal groups. In total 22 different species found, including: Andrew, Arnoux, Baird, Blainville,Cuvier, Gervais,Gingo,Gray,Hector,Hubb,Longman, Northen Bottelnose whale,Perrin, Peruvian, Sowersby, Spade-toothed, Strap-toothed, Stejneger, Tasman and True beaked whales.

Blainville’s beaked whale, or the dense-beaked whale, is the widest ranging mesoplodont whale and perhaps the most documented. This species of beaked whale is found in tropical and warm waters in all oceans. About one quarter of the world’s 86 whale and dolphin species belong to the family of beaked whales.

These toothed (most just have one pair of teeth) whales are notable for their elongated beaks.

Beaked whales are moderate in size, 4 to 13 metres (13 to 43 ft) and weighing 1 to 15 tonnes. Individual species are very difficult to identify in the wild, since body form varies little from one species to another.

Among air-breathing animals, beaked whales are some of the most extreme divers: : Cuvier’s beaked whales dive for an hour at a depth over 1,000 m (3,300 ft) and records of 9,816 feet (2,992 meters), while a second stayed down for 138 minutes has been published.

 

Pilot whales

The pilot whale is like the killer whale, a member of the dolphin family, and is second only to the killer whale in size.

Pilot whales are actually two species: Globicephala melas (long-finned) and Globicephala macrorhynchus (short-finned) and are found in both the northern and southern hemispheres.

Adult males’ measure up to 20 feet (6.1 m) and weigh up to 3 tons. Adult females’ measure up to 16 feet (4.9 m) and weigh up to 1.5 tons. Their intelligence equals the bottlenose dolphin.

The pilot whale is extremely social and is in groups of 20-90. Pilot whales are often found in captivity. They have been trained by the US Navy to locate military equipment from deep ocean depths for retrieval.

“Drive fisheries,” where groups of pilot whales are herded to the beach for slaughter, have taken place on Cape Cod, Newfoundland, the Faroe Islands, Shetland, and Orkney Islands, Iceland, and Norway. The whales have been killed for meat, bone, fertilizer, and oil. In some places, such as the Faroe Islands, the kill continues today despite an obvious decrease in whale numbers and proven facts that whale meat, due to pollution, no longer is adapted for human consumption.