The Whale Shark

The Skin and More

The Whale Shark's Skin

The whale shark's skin is toughest, thickest of all the animals in the world. Their skin can be up to 14cm thick and it is covered in dermal denticles. Dermal denticles are tiny cartilaginous tooth-like structures. The purpose is of them is make the skin very rough and they reduce the drag of water, so that the whale shark can swim in the water with more easy.

The whale shark's skin is counter-shaded which means it is pale on the bottom of the whale shark and dark on the top. This allows them to blend in with the reflection of the sky to any creatures looking up at them or to blend in, in the deep depths of the ocean. The whale shark's dark sides and back are a dark grey-brown color which appear blue when they are underwater. They are also covered in small white to pale yellow dots and think vertical striped. The design and or pattern of these dots and stripes can be used to identify which whale is which because no two designs/patterns are the same.

"Intriguing Whale Shark Facts and Legends." Whale Shark Facts. N.p., n.d. Web. 17 Jan. 2014.

Whale Shark's Skeleton

Bones & Teeth

The whale sharks is an elasmobranch This means that instead of their skeleton being made up of bone, it is instead made up of cartilage. Cartilage is a tough, flexible tissue. Also, cartilage cannot preserved as well as bone so the information we know about early whale sharks comes mainly from their teeth. They also have large external slits as a way for water to exit after passing over the gills, instead of having a single plate of bone over their gills, like most bony fish.

The whale shark also have over three hundred teeth, but they do not need their teeth in order to eat their planktonic prey. This has caused their teeth, over the year, to shrink down to just three millimeters in size. Their genus name is 'Rhincodon' which is Latin and translates to 'rasp-tooth'. That is essentially saying that the teeth are so small that are considered to be a filer or a grater.

Potenski, Matthew. "Whale Shark Expedition: The World's Largest Fish." Whale Shark Expedition: The World's Largest Fish. N.p., n.d. Web. 05 Feb. 2014.

"Facts About Whale Sharks." Marine Life. N.p., n.d. Web. 05 Feb. 2014

Whale Shark's Muscles

Whale shark's have all three types of muscle. They have cardiac muscles for partially high stamina and continuous performance. They also have skeletal muscles that subject to direct control by the brain and are moved on command. Lastly, they have smooth muscles that surround their inner organs and are not moved on command, but automatically.

Way back when, all sharks had the ability to use buccal pumping to survive underwater. Buccal pumping is when the muscles pull the water into the mouth and over the gills. However, when sharks became more active whale sharks lost the ability to use buccal pumping to survive underwater and now just use ram ventilation. Ram ventilation is when the shark takes the water in while swimming and lets it flow freely through the gill slits. This adaption has the caused the whale shark to use less muscles while breathing.

"ANATOMY." Sharkproject. N.p., n.d. Web. 18 Feb. 2014.

Edmonds, Molly. "Will a Shark Drown If It Stops Moving?" HowStuffWorks., 09 June 2008. Web. 18 Feb. 2014.

Whale Shark's Nervous System

Whale shark's are a type of animal that because of its nervous system it can sense electric fields even in the dark. It's able to that through its many nerve endings. Being able to sense these electric fields allows the whale to hunt for its prey and is a huge advantage because its eye sight is so poor. Its eyes are also very small which plays into why their eye sight is so bad. Also, since the whale shark lives in dark depths of the ocean it has adapted to where eye sight is not an important sense as to hearing and smell.

A whale shark has an incredibly sensitive sense of smell and because of that they are able to pick up chemicals in the water, which also allow it to find its prey. There are nasal grooves above the mouth of a whale shark that allows a continuous stream of water to flow in so the whale shark can smell the chemicals. Whale sharks have all this because they have a lateral nervous system. They have rows on both sides of the shark that communicate with the lateral nervous system. These openings are called Ampullae of Lorenzini. Through those the whale shark is able function and thrive as it does to this day!

Prevost, John F. "Whale Sharks." ABDO & Daughters, n.d. Web. 25 Feb. 2014

Taylor, Geoff. "Whalesharks." Whalesharks. N.p., n.d. Web. 26 Feb. 2014.

Scientists free a whale shark from a fishing net in Indonesia - Conservation International (CI)

Circulatory System

Whale Shark has a closed circulatory system. Also the Whale Shark's blood is pumped by the heart through the afferent branchial arteries which are also know as ventral aorta. It capillaries in the gills, which is where blood is oxygenated. Then the blood flows through efferent branchial arteries which are paired dorsal aorta. After that it goes through thew tissues of the body, and then back to the heart in the veins.

"Shark Anatomy - Enchanted Learning Software." Shark Anatomy - Enchanted Learning Software. N.p., n.d. Web. 06 Mar. 2014.

Whale sharks at Georgia Aquarium
Whale Shark Encounter - ABC News

Respiratory System

The whale shark uses it's gills to filter oxygen from the water to allow it to breathe. When the water passes over the gills of a whale shark, capillaries, or a system of very fine blood vessels absorb the oxygen from the water. Whale sharks have 5 pairs of gill slits on either side of its head. Whale sharks specifically expel the filtered water through their gills.

"Gills - Shark Anatomy -" Gills - Shark Anatomy - Enchanted Learning, n.d. Web. 29 Mar. 2014

Digestive System & Excretory System

Whale shark's feed by using suction to take in large of amounts of small fish and plankton. The food will then move from the mouth to the 'J' shaped stomach. It is there that the food is stored and the initial digestion occurs. Most of the unwanted food parts don't make it to the stomach and are coughed back up. Whale shark's have a short spiral valve with many turns instead of an intestine. The valve allows for there to be a very long surface area for the digestion of food and the food will not come out till it's completely digested.

After the food is digested waste products are passed to the cloaca and vent. The cloaca is a small on the underside of their body where the waste will come out of the whale shark.

The picture below is of a man in the 'olden times' sitting in part of a whale shark's mouth.

"Feeding and Digestion - Physical Characteristics of Sharks." Feeding and Digestion. N.p., n.d. Web. 3 Apr. 2014.

Reproduction System

Male whale shark's have reproductive organs called claspers, which developed from the inner rim of the pelvic fins. Then there is a tube that runs through each clasper. The front opening is called an apoplye and the rear one is called a hypopyle. Female shark's on the other hand have a cloaca which is an opening that is used for reproduction.

When the whale sharks mate the sperm is washing into the female's cloaca by the water. It either fertilizes the eggs at once or can be stored for a while.

Females then go to secluded places to give birth because they can only defend themselves within limits while pregnant. However, once she's given birth the baby whale shark will have to fend for its self because whale sharks do not take care of their young.

"ANATOMY." Sharkproject. N.p., n.d. Web. 16 Apr. 2014.

Pregnant female Whale Shark