Whales & Dolphins

Whale is the common name for various marine mammals. 

Sperm_whale_from_above

The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to the suborder Odontoceti (toothed whales). This suborder includes thesperm whale, killer whale, pilot whale, and beluga whale.

The other Cetacean suborder, Mysticeti (baleen whales), comprises filter feeders that eat small organisms caught by straining seawater through a comblike structure found in the mouth called baleen. This suborder includes the blue whale, the humpback whale, thebowhead whale and the minke whale.

All cetaceans have forelimbs modified as fins, a tail with horizontal flukes, and nasal openings (blowholes) on top of the head.

Whales range in size from the blue whale, the largest animal known to have ever existed at 30 m and 180 tonnes, to pygmy species such as the pygmy sperm whale at 3.5 m.

Whales inhabit all the world’s oceans and number in the millions, with annual population growth rate estimates for various species ranging from 3% to 13%. Whales are long-lived, humpback whales living for up to 77 years, while bowhead whales may live for over a century.

 

Why are Whales being hunted:

  • Whales are hunted mostly for food and to make whale oil.
  • Whale oil is used in products like soap, detergents, cosmetics, margarine and insecticides.
  • Whale oil is also used in engineering industries to make explosives, engine transmission fluids and hydraulic lubicants.
  • Patents have also been filed in the United States, Japan and Korea to turn whale oil into biodiesel.

Whales & Dolphins are categorized under the list of cetaceans.

hbw1

The order Cetacea includes whales, dolphins, and porpoises. It has 88 living species, divided into the suborders Odontoceti (the toothed whales, including dolphins and porpoises) and Mysticeti (the baleen whales).

Cetaceans are aquatic mammals characterised by having streamlined body shapes, paddle-shaped front limbs and vestigial hind limbs. Their tails have been flattened into flukes to aid propulsion.

hbw

Different Types of Whales:

1) Baleen whales

Baleen whales are characterized by having baleen plates for filtering food from water, rather than having teeth.  

a) Right whales

Northern Right whales

Photo: Northern Right Whales

north atlantic rightwhales

Photo: North Atlantic Right Whales

Southern-Right-Whale-Pictures

 

Photo: Southern Right Whale

The right whales (North Atlantic Right Whales, Northern Right Whales and Southern Right Whales) comprises the following features: a smooth belly and chin, with no ventral grooves; a distinctive head shape with strongly arched, narrow rostrum and bowed lower jaw; lower lips that enfold the sides and front of the rostrum; long, narrow, elastic baleen plates (up to 9 times longer longer than wide) with fine baleen fringes; the fusion of all the cervical vertebrae and other skeletal characteristics; and a slow swimming speed. 

 

b) Rorquals

Rorquals are the largest group of baleen whales.

They include the largest animal that has ever lived, the blue whale, which can reach 150 tonnes and even the smallest of the group, the northern minke whale, reaches 9 tonnes.

Blue_Whale_001_noaa_body_color

Photo: Blue Whale

Minke_Whale_(NOAA)

 

Photo: Minke Whale

 

All members of the family have a series of longitudinal folds of skin running from below the mouth back to the navel. These are understood to allow the mouth to expand immensely when feeding. All rorquals have ventral grooves, and are the only cetaceans to have them. Additionally, they all have dorsal fins, broad, gently curving rostra and short baleen plates.

 

c) Gray whale

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Photo: Grey Whale

The gray whale has been placed in a family of its own as it is sufficiently different from the right whales and the rorquals. The gray whale is the only benthic feeding baleen whale, filtering small organisms from the mud of shallow seas. They also have a gestation period of over a year, which is unusual for baleen whales.

 

d) Pygmy right whale

The pygmy right whale shares several characteristics with the right whales, although having dorsal fins separates them from right whales, and they have a very distinctive jaw configuration. Pygmy right whales’ heads are no more than one-fourth the size of their bodies, whereas the right whales’ heads are about one-third the size of their bodies.

 

2)Toothed whales

The toothed whales (systematic name Odontoceti) form a suborder of the cetaceans. As the name suggests, the suborder is characterized by having teeth (rather than baleen). Toothed whales are active hunters, feeding on fish, squid, and in some cases other marine mammals.

a) Oceanic dolphins

Oceanic dolphins are the members of the Delphinidae family of cetaceans. These aquatic mammals are related to whales and porpoises. As the name implies, these dolphins tend to be found in the open seas.

Six of the larger species in the Delphinidae, the killer whale (orca) and its relatives, are commonly called whales, rather than dolphins. They are also sometimes collectively known as “blackfish”.

Killerwhales_jumping

 

Photo: Killer Whales

b) Narwhal and Beluga

The cetacean family Monodontidae comprises two unusual whale species, the narwhal, in which the male has a long tusk, and the white beluga.

BelugaPhoto: Beluga Whale

 

Narwhal

 

 

Photo: Narwhal

The Monodontidae lack dorsal fins, which have been replaced by tough, fibrous ridges just behind the midpoints of their bodies and are probably an adaptation to swimming under ice, as both do in their Arctichabitat. The flippers are small, rounded and tend to curl up at the ends in adulthood. All, or almost all, the cervical vertebrae are unfused, allowing their heads to be turned independently of their bodies. None has any throat grooves.

 

c) Porpoises

Porpoises are small cetaceans of the family Phocoenidae. They are distinct from dolphins, although the word “porpoise” has been used to refer to any small dolphin, especially by sailors and fishermen. The most obvious visible difference between the two groups is porpoises have spatulate (flattened) teeth distinct from the conical teeth of dolphins. In addition, porpoises are relatively r-selected compared with dolphins: that is, they rear more young more quickly than dolphins. All six species have small flippers, notched tail flukes, and no beaks. All carry at least 11 pairs of small teeth in their upper and lower jaws.

Porpoises

 

Photo: Porpoise posing

Porpoises, divided into six species, live in all oceans, mostly near the shore. Probably best known is the harbour porpoise, which can be found across the Northern Hemisphere.

 

d) Sperm whale

Mother_and_baby_sperm_whale

 

Photo: Mother & baby Sperm Whale

The sperm whale characteristically has a large, squarish head one-third the length of its body; the blowhole is slightly to the left hand side; the skin is usually wrinkled; and it has no teeth on the upper jaw.

e) Dwarf and Pygmy Sperm whales

The dwarf and pygmy sperm whales resemble sperm whales, but are far smaller. They are dark grey, dorsally, while ventrally they are lighter. They have blunt, squarish heads with narrow, underslung jaws; the flippers are set far forward, close to the head and their dorsal fins are set far back down the body.

f) Beaked whales

A beaked whale is any of at least 21 species of small whale in the family Ziphiidae. They are one of the least-known families of large mammals: several species have only been described in the last two decades, and it is entirely possible that more remain as yet undiscovered. Six genera have been identified.
Beaked_Whale
Photo: Beaked Whale

They possess a unique feeding mechanism known as suction feeding. Instead of catching their prey with teeth, it is sucked into their oral cavity. Their tongue can move very freely, and when suddenly retracted at the same time as the gular floor is distended, the pressure immediately drops within their mouth and the prey is sucked in with the water. The family members are characterized by having a lower jaw that extends at least to the tip of the upper jaw, a shallow or non-existent notch between the tail flukes, a dorsal fin set well back on the body, three of four fused cervical vertebrae, extensive skull asymmetry and two conspicuous throat grooves forming a ‘V’ pattern. 

g) River dolphins

River dolphins

River dolphins are five species of dolphins which reside in freshwater rivers and estuaries. They are classed in the Platanistoidea superfamily of cetaceans. Four species live in fresh water rivers. The fifth species, the La Plata dolphin, lives in saltwater estuaries and the ocean. However, it is scientifically classed in the river dolphin family rather than the oceanic dolphin family. All species have adaptations to facilitate fish catching: a long, forceps-like beak with numerous small teeth in both jaws, broad flippers to allow tight turns, small eyes, and unfused neck vertebrae to allow the head to move in relation to the body.

 

Relation of Whales & Humans

Whaling

Picture: Dutch whalers near Spitsbergen.Abraham Storck, 1690
Map showing IWC non-members such as Canada and most Middle Eastern and African countries in white

Picture: World map of International Whaling Commission (IWC) members/non-members(member countries in blue)

Some species of large whales are listed as endangered by multinational organizations, such as CITES, as well as governments and advocacy groups; this is primarily due to the impact of whaling. Whales have been hunted commercially for whale oil, meat, baleen and ambergris (a perfume ingredient from the intestine of sperm whales) since the 17th century.  At its peak, in 1846, the American whaling industry employed more than 70,000 people and 736 vessels. More than 2 million were taken in the 20th century,  and by the middle of the century, many populations were severely depleted.

The International Whaling Commission banned commercial whaling in 1986. The ban is not absolute, however, and some whaling continues under the auspices of scientific research (most of the time not proved ) or aboriginal rights; current whaling nations are Norway, Iceland and Japan and the aboriginal communities of Siberia, Alaska and northern Canada.

Bycatch

Several species of small whales are caught as bycatch in fisheries for other species. In the Eastern Tropical Pacific tuna fishery, thousands of dolphins drowned in purse-seine nets, until preventive measures were introduced. Gear and deployment modifications, and eco-labelling (dolphin-safe or dolphin-friendly brands of tuna), have contributed to a reduction in dolphin mortality by tuna vessels. 

Naval sonar

Environmentalists speculate that advanced naval sonar endangers some cetaceans, including whales. In 2003, British and Spanish scientists suggested in Nature that the effects of sonar trigger whale beachings and to signs that such whales have experienced decompression sickness.  Responses in Nature the following year discounted the explanation. 

Mass beachings occur in many species, mostly beaked whales that use echolocation for deep diving. The frequency and size of beachings around the world, recorded over the last 1,000 years in religious tracts and more recently in scientific surveys, have been used to estimate the population of various whale species by assuming that the proportion of the total whale population beaching in any one year is constant. Beached whales can give other clues about population conditions, especially health problems. For example, bleeding around ears, internal lesions, and nitrogen bubbles in organ tissue suggest decompression sickness. 

In culture

Photo: Whale weather-vane atop the Nantucket Historical Association Whaling Museum displaying a Sperm Whale.

Whales were little understood for most of human history as they spend up to 90% of their lives underwater, only surfacing briefly to breathe. Many cultures, even those that have hunted them, hold whales in awe and feature them in their mythologies.

 

Save the Whales & Dolphins, YOU can make a difference!

Join us as ONE VOICE to:

Reduce demand for illegal wildlife parts and products by encouraging others to ask questions and get the facts before buying any wildlife or plant product.

Push governments to protect threatened animal populations by increasing law enforcement, imposing strict deterrents, reducing demand for endangered species products.

Speak up on behalf of those on the frontlines being threatened by armed poachers so they are properly equipped, trained and compensated.