Specked+Whale

//Extinct animal: Basilosaurous// //Modern animal: Killer Whales// //Future animal: Speckled Whales// The speckled whale, or the //orcinus rex//, is one of the largest predators in the world 25 million years after human civilization. Each measuring about 10 to 12 metres long, these speckled whales have evolved from offshore killer whales.


 * Classification :**
 * ** Kingdom ** || Animalia ||
 * ** Phylum ** || Chordata ||
 * ** Class ** || Mammalia ||
 * ** Order ** || Cetacea ||
 * ** Suborder ** || Odontoceti ||
 * ** Family ** || Delphinidae ||
 * ** Genus ** || Orcinus ||
 * ** Species ** || Rex ||

**Habitat**

The average temperature has risen to 25 degrees Celsius. Despite the human mass extinction that occurred over 8 million years ago, the effects of global warming remain, making Earth a hot, polluted planet. As a result, the two Polar Regions have completely melted, causing the sea level to rise significantly (fig. 1). This means that many of the continents, which have moved slightly, to submerge partially or entirely (fig. 1), which led to the extinction of many animals, particularly land mammals that lived on the fringes. The oceans were also affected by the lingering pollution – oxygen levels in areas making up 1/5 of the oceans are now much lower than they were before, leading to the extinction, migration and evolution of certain fish and marine life.

However, due to their ability to survive in a large variety of ocean temperatures, the descendants of killer whales, speckled whales, remain extant. Though they can live in most saltwater conditions, speckled whales tend to roam in warmer, tropical oceans where food is abundant. They are found in both coastal and wide oceanic areas. Speckled whales generally remain about 500 metres under water, but they sometimes be found in much deeper waters to cool off, as far as 1000 metres deep.

Since the disappearance of many marine mammals such as leopard seals, speckled whales’ primary prey is large fish and sharks. During this time, new species of fish in the warmer seas as well as their ability to adapt allowed sharks to live and thrive in these warm oceans, resulting in large numbers of sharks in warm oceans all over the world. This naturally affected the speckled whales, as these sharks were their main choice of prey due to their large sizes. However, speckled whales also occasionally attack sphere whales, which are located much deeper in the ocean.

On the other hand, the only predators of speckled whales are sharks, which have evolved to be much larger (up to 16 metres long – as long as the megalodon) and swim much faster. However, speckled whales are not their main prey as it is too risky to handle a pod of speckled whales. This is why sharks usually attack only when speckled whales are alone and weakened.

**Adaptations**

Between the twenty or so years since the extinction of killer whales, speckled whales have been chosen through natural selection as they have superior adaptations (fig. 2) which help them survive better in the new but polluted world.

**Blowhole and its Filtration System**

Over the time, speckled whales have still retained their blowholes. Why, you may ask? Despite the fact speckled have been living in the water for millions of years, these mammals never developed gills. This is because they require about 40 times water through gills than air through lungs for the same amount of oxygen, rendering it far too inefficient for this warm blooded animal which requires much more oxygen to keep up their high metabolism and high level of activities, not to mention the decreased amount of oxygen levels in the ocean during recent years.
 * [[image:blowhole_diagram.jpg width="480" height="408" align="right" caption="Fig. 3: Diagram of an individual blowhole"]]Adaptation ** :

Instead, speckled whales have evolved to have multiple blowholes (similar to a watering can) (fig. 2) which are all connected to the same nasal passages. Each act as air filtrates which filter the air immediately before taking in the oxygen with a thin layer of tissue on top of each blowhole as well as sticky cilia in the nasal passages. The layers of tissue are in fact a very thin but absorbent material which traps passing molecules into the pores. The closely knitted cilia (fig. 2), coated with mucus, are located directly underneath the layer of tissue, and traps any escaped particles. While the oxygen is directed inside, the blowholes closes with the contraction of a muscle and the whale submerges. When it resurfaces, it relaxes the muscle, exposing the blowholes, and all the unwanted particles, along with the water resting on the blowhole, carbon dioxide, mucus and layers of tissue are ejected upwards in an almost explosive manner, seen as a white sprinkle of water shooting up 3 metres into the air. Right after exhalation, the speckled whale closes up its blowholes, and begins to form layers of disposable tissue underneath once again (this is possible due to the small size of each of these blowholes, which makes this a much easier and faster job), ready for the next inhalation and exhalation three hours later.

The kidney has also adapted to continuously excrete any remaining toxic chemicals, keeping the blood at an acceptable level.

** How it helped the animal survive ** : Without the blowhole’s filtration system, the speckled whale may not be able to cope with the extra particles passing through its lungs. Substances such as tar may clog up the bronchi or even the alveoli.

** Environmental pressure ** : As the air has become far too polluted for the speckled whale to extract oxygen from, while though the ocean is also polluted, it is not as toxic as the air and gills are a better filtration system.

**Diving Down into the Bathypelagic Zone**

In the afternoon, when the ocean temperatures are at its highest, speckled whales dive deeper down into the ocean for a cooler environment. Their strong, muscular bodies allow them to swim deep into the bathypelagic zone (fig. 3), about 1000 metres under the surface, where temperatures are about 10 degrees Celsius.
 * Adaptation ** :

If ever they become hungry, speckled whales would rely heavily on echolocation to search for pods of sphere whales, the descendants of blue whales, aiming for the calves or even the females. Male sphere whales, however, are too large and aggressive for the speckled whales to kill, even when in their pods.

Though this behavior is mainly for the speckled whale’s own comforts, a temperature too high may result in heat stroke, which ultimately kills the speckled whale.
 * How it helped the animal survive ** :

Due to the rise in global temperature, the oceans worldwide are also greatly affected. As a result, speckled whales have evolved to dive deeper for longer periods of time and adapted to the environments deep in the sea.
 * Environmental pressure ** :

**Social Structure**

Speckled whales, have retained their ancestors’ complex social structures. They form what is called matrilineality, where the eldest female speckled whale leads a line of her descendants. From these matrilines form closely related groups called pods (fig. 5). They consist of about one to four matriline, and have about 20 speckled whales on average.
 * [[image:speckled_whale_pod.jpg width="518" height="307" align="right" caption="Fig. 5: A speckled whale pod"]]Adaptation ** :

Offspring of speckled whales share a close bond with their mothers; not only do their mothers tend to the offspring’s needs, they discipline them, and teach them how to hunt and communicate starting from the second day of birth.

As the young and vulnerable may be prone to attack by sharks reaching up to 16 metres long (as long as its ancestor, the megalodon), older male speckled whales travel on the outer area of the pod, while the females and the young remain on the inside. If a shark or multiple sharks approach the pod, several males will remain behind, while stronger, older males will attack accordingly, such as ramming the shark’s gill slits with its head, which would knock it out unconscious then killing it for a meal.

**How it helped the animal survive** : <span style="font-family: Arial,sans-serif; font-size: 10pt;">If speckled whales do not live in pods or matrilines, the young or the weak are very vulnerable to attacks by sharks, as they have lost the protection needed to survive.

<span style="font-family: Arial,sans-serif; font-size: 10pt;">The reason for these groups may have been due to the threat which sharks pose to the survival of young calves, which led speckled whales to protect their young.
 * Environmental pressure ** :

<span style="color: #6a86b4; font-family: Tahoma,Geneva,sans-serif; font-size: 22px;">**Strategic Hunting**

<span style="color: windowtext; font-family: Arial,sans-serif;">Speckled whales are excellent in hunting due to their high level of intelligence, which allows them to hunt strategically through observation of the prey’s behaviour. This is used mainly on sharks (fig. 6), as they are the speckled whales’ main source of food. As speckled whales understand that once a shark is turned over, it would enter a paralyzed state, which is known as “tonic immobility”. There are three main strategies used by speckled whales when attacking sharks:
 * Adaptation ** :

<span style="color: windowtext; font-family: Arial,sans-serif;">The first technique is simply by hitting the shark’s gill slits with its head, then turns it over to its back, rendering immobilized and kills it.

<span style="color: windowtext; font-family: Arial,sans-serif;">The second technique is when speckled whales force the shark up, then gives continuous upward thrusts of their strong tail, creating a vortex, pushing the shark up even further. When it reaches the surface, one or two speckled whales would pivot and lift its tail out of the water, and slams it down simultaneously. Before the shark could recover, the speckled whales would use their powerful jaws to grab the shark and flip it upside down and kills it. <span style="font-family: Arial,sans-serif;">The final technique is when the speckled whale circles in on an individual shark, then approaches it from below and attacks its underbelly, causing it to flip, then eats up the shark.

<span style="font-family: Arial,Helvetica,sans-serif;">** How it helped the animal survive ** : <span style="font-family: Arial,sans-serif;">Through the practice of these efficient hunting strategies, speckled whales are able to hunt down sharks while sustaining little or no injuries, despite the lethality of sharks are capable of killing fully-grown speckled whales

<span style="font-family: Arial,Helvetica,sans-serif;">** Environmental pressure: ** <span style="font-family: Arial,sans-serif;">Since sharks, which are the speckled whales’ main sources of food, have evolved to be much larger and faster, speckled whales would need to hunt strategically in order to defeat such a large prey.

<span style="color: #6a86b4; font-family: Tahoma,Geneva,sans-serif; font-size: 22px; line-height: 33px;">**Muscular Body and Tough, Speckled Skin**

<span style="color: windowtext; font-family: Arial,sans-serif;">The large, muscular body (fig. 7)of the speckled whale helps them navigate quickly and agilely throughout both the rough and the calm ocean currents throughout the world. Though it has lost some of its stored fat as it does not need an insulator, it still retains the barrel-like body shape for control.
 * [[image:speckled_whalelabel2.jpg width="400" height="210" align="right" caption="Fig 7: Speckled whales have a large, muscular body covered with white speckles"]]Adaptation ** :

<span style="color: windowtext; font-family: Arial,sans-serif;">Its body is also covered with a layer of tough, impermeable skin. Not only does this stop chemicals from seeping in, the tough skin also makes it more difficult for smaller sharks to bite through, though larger, stronger sharks will still be able to penetrate the skin.

<span style="color: windowtext; font-family: Arial,sans-serif;">In addition, the skin, as the name suggests, is speckled (like animals such as hyenas)(fig.7). This helps them to blend in the environment, which helps the weaker speckled whales to hide from large sharks. This also contributes to cooling down the whale, as the white speckles will reflect light and UV rays, which can be harmful for speckled whales. They put this to use also by flipping over their bodies, with their white underbelly facing upwards. However, this is uncommon as it makes them more vulnerable, which is why they do this only when in large groups.

<span style="font-family: Arial,sans-serif;">The speckled whale’s large, muscular body gives it not only flexibility but also strength to attack effectively and precisely, which makes it easier to attack prey – especially if they are larger in size. Its skin prevents chemicals from getting into the body of the speckled whale, and also acts as a protective barrier against sharks.
 * How it helped the animal surviv<span style="font-family: Arial,Helvetica,sans-serif;">e **<span style="color: windowtext; font-family: Arial,Helvetica,sans-serif;">:

<span style="font-family: Arial,Helvetica,sans-serif;">** Environmental pressure ** : <span style="color: windowtext; font-family: Arial,sans-serif;">The increase of toxic chemicals in the sea has led to the evolution for thick, impermeable skin, the increase in both size and lethalness of sharks has led to the evolution for its tough skin and the need to hunt such fast prey and to go down deep under water has resulted in the speckled whale’s large, muscular body.


 * <span style="color: #6a86b4; font-family: Tahoma,Geneva,sans-serif; font-size: 25px;">Possible Selection Pressure **

<span style="color: windowtext; font-family: Arial,sans-serif;">Resident and transient killer whales became extinct global warming continued, while it was the offshore killer whales which evolved into speckled whales which are well adapted to the polluted world. As the oceans became more and more polluted, the variety and amount of prey – fish and marine mammals in particular – decreased rapidly. The fish were unable to adapt to the sudden change in acidity and toxins in the oceans, and many became extinct, while only few were able to adapt and evolve. The number of marine mammals plummeted due to this. As the number of fish declined, marine mammals found hunting much more difficult and competitive because almost all of them fed on fish. As a result, both resident and transient killer whales also found it difficult to hunt from the lack of fish and marine mammals, and eventually became extinct.

<span style="font-family: Arial,sans-serif;">However, offshore killer whales, which not only fed on fish, but also sharks and whales, put this to good use and hunted whales instead, as sharks, which also fed on fish, experienced a dip in population numbers but managed to survive in the end.

<span style="color: #6a86b4; font-family: Tahoma,Geneva,sans-serif; font-size: 25px;">**Bibliography**


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 * Than, Ker. (2009). //Global Warming to Create “Permanent Ocean Dead Zones”?//. Retrieved 25 June 2011, from []
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 * Wikipedia. (2011). //Sperm Whale//. Retrieved 25 June 2011, from []


 * <span style="color: #6a86b4; font-family: Tahoma,Geneva,sans-serif; font-size: 25px;">Images Sources **


 * Fig. 1: The world 25 million years after human civilization. Source: []
 * Fig. 2: Labelled diagram of a drawing of a speckled whale. Source: Joyce Ng
 * Fig. 3: Diagram of an individual blowhole. Source: Joyce Ng
 * Fig. 4: Diagram of the ecological zones in the ocean. Source: []
 * Fig. 5: A speckled whale pod. Source: [] (with edits)
 * Fig. 6: A speckled whale about to attack a small shark. Source: [](with edits)
 * Fig 7: Speckled whales have a large, muscular body covered with white speckles. Source: Joyce Ng

<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">//By Joyce Ng 10A//