The Whale Shark – Aquarius

General facts About “Whale Sharks”.

A gentle giant featured in films and documentaries; the Whale Shark has a reputation for its majesty. This record-holding fish is one of the most notable in the animal kingdom. With its impressive size and beauty, it’s no wonder the world is enamored. This is the largest fish and the largest living non mammalian vertebrate on the planet. Due to their size, they can process 6,000 liters of water every hour. The Whale Shark is so distinct from other sea creatures, that it is the only member of its family: Rhincodon. It is also the last non-extinct member of the Rhincodontidae family.

Introduction:

Given their name, you might think these creatures are related to whales, but they are actually classified as a type of shark. Yet these are known as gentle giants for an important reason. The behaviour of the Whale Shark is more docile like a whale, as they feed with less predatory instincts, and pose no danger to humans.

This safety and grandeur make these sharks a popular tourist attraction for humans. Snorkelers, scuba divers, and tourist boats will flock to Whale Sharks when they surface near land. But their economic value does not stop there. In addition to this tourism industry, some countries place a high value on the meat, fins, and liver oil of Whale Sharks. With the value of one carcass starting at $30,000 and going as high as $250,000.

The Whale Shark: Out of the Blue!

What is the size, weight & colour of the Whale Shark?

This large specimen weighs up to 19,000kgs and can grow up to 20 meters. That’s about 3 Giraffes stacked on top of each other! An average size is 6-12 meters.

The Whale Shark has a beautiful and distinct appearance. Their backs are grey with white spots and stripes all over, which are completely unique to each specimen. These spots help them camouflage from predators, as they disperse sunlight and make them harder to see. Their bellies are also white so they can be hidden from below.

What type of vision does the Whale Shark have, and what sounds do they make?

This creature’s eyes are incredibly small compared to the size of its body. Which means they likely do not rely on their eyesight to get around. Mirrors have been found in the back of their retina to help them see in the dark if they need to. Whale Sharks instead rely on the Ampullae of Lorenzini, which is located on their head, and detects electromagnetic fields from other animals.

Only one video has been found of Whale Sharks making noise. Sharks typically do not make noise, so it came as a surprise to many. It has been named a “Dino Roar” due to their ancestors dating back 450 million years but was more accurately described as a raspy groan.

Are there any special or unique physical attributes?

The Whale Sharks’ most special feature is their mouth, which has not only an interesting wide shape but many other unique qualities. In this shark’s 1.5m wide mouth you will find 3000 tiny teeth, which aren’t used often, as they are filter feeders. The size of their mouth is an asset in hunting as it can expand to dramatic sizes, which impacts the flow of water current for small fish nearby. They additionally have whiskers (barbels) like a catfish, which act as a sensory organ to aid their hunting.

Another interesting feature of this shark is the placement of its gills. One of the 5 large gill slits they have is located behind the Shark’s eye, making it possible for these leisure swimmers to take a nap on the ocean floor.

How fast is the Whale Shark?

Whale Sharks travel at their leisure, with a lazy-river speed of 5 kilometers per hour.

How do they hunt, and what do they eat?

While they are apex predators, the Whale Shark is a passive feeder when large prey is not present. This means they can filter small plankton and other small marine life. This is achieved through gulping water, sifting the food, and releasing excess water and debris. These creatures have been seen coughing as a result, as the aimless feeding causes small blockages in the filter pads.

Plankton is their main food source when they passively feed. However, when the Whale Shark is actively hunting, they will target sardines, mackerels, anchovies, squid, and tuna. An example of their tactical hunting is that they target other fish spawning sites. After waiting near coral reefs, they will steal eggs from smaller fish in spawning season.

They have also been known to collect in groups at feeding grounds in the spring, but these sharks normally feed in solitude.

Who are their natural enemies?

Juvenile Whale Sharks can be attacked by larger fish before they reach maturation. Packs of Killer Whales are especially known to target them.

Fully grown Whale Sharks are too large to be hunted by other fish.  But parasites can still invade their systems and cause malnutrition and premature death. This alongside poachers and fishermen means mature Whale Sharks have little chance of living to 130 years.

Where do they live?

This is a tropical shark, with 75 percent coasting through the Indian and Pacific oceans. Focusing largely in areas around South Africa, Central America, and South America. The other 25 percent can be seen seasonally in Atlantic waters, but they don’t go any further north than the East Coast of the United States.

What are their migration habits and routes?

Every spring, these creatures migrate to the Ningaloo Reef on the continental shelf of Australia. Here they will find plankton and a plentiful supply of other fish to feed on. This is because the coral is spawning and attracts many smaller fish and sea insects to feed as well.

How can they travel such long distances?

Whale Sharks have been confirmed to be one of the Oceans most long-distance swimmers. They swim up to 90km a day, which takes little effort because of their size and powerful fins. Scientists tracked a Whale Shark that traveled 20,142 kilometers in 841 days. These sea creatures have to travel to eat a lot so they can maintain their size.

All about Reproduction.

The Whale Shark reproduces differently to other sea creatures where eggs are concerned. The female is ovoviviparous, which means she will produce eggs, and carry them inside her for the duration of their incubation. This prevents other carnivorous fish from eating them. She will then give birth to her pups, but not all at once. Female Whale Sharks will release their pups over a prolonged period. The infant sharks will be 40-60cm from birth.

Whale Sharks also take a long time to reach sexual maturity, with an average of 25 years. This late blooming, in relation to their 130-year lifespan, means they will still have plenty of time to reproduce. But many small Whale Sharks do not make it to maturity.

Life Span.

The Whale Shark has been confirmed to live between 80 and 130 years. This depends on internal and external factors on their quality of life.

Myths.

Many people believe that while a Whale Shark does not want to eat humans, but could if they tried. This is physically impossible, because their throats are the size of a human fist. If a swimmer somehow found themselves sucked into a Whale Sharks mouth, this shark would quickly spit them back out. The largest risk the Whale Shark poses to humans is accidentally swatting them with their large fins.

What threats does the Whale Shark face?

Because the Whale Shark relies heavily on the coral reef, the loss of this feeding ground is their most significant threat. Humans focus a lot of fishing and coastal development around the reef, which aids its decline significantly. With pollution, boat traffic, and fishing, every interaction with the ecosystem pushes it toward ecological collapse.

In addition to a threatened ecosystem, these fish are also subject to untreated injuries. Many Whale Sharks have been found with injuries and torn fins due to fishing and tourism boats. While sensors have been developed for boats to detect obstructions in the water, this technology is expensive and not common. Many Whale Sharks die from infected wounds caused by boats.

Why are they endangered?

The slow maturation makes replenishing Whale Shark stock a challenge. While places like the Philippines have banned all fishing for Whale Sharks, this rule does not exist everywhere. Their highly valued carcasses make them a prize for fishermen.

Additionally, Shark Fin Soup is a common delicacy enjoyed by many people all over the world. Whale Sharks have large fins, which makes them a prime target for finning.

Endangered Ranking – ICUN.

The Whale Shark is ranked as endangered on the ICUN list of endangered species. Populations continue to decrease as poaching and habitat loss increase. The Indo-Pacific Whale Sharks have lost 63 percent of their population since 1950. While Atlantic Whale sharks have lost 30 percent. It would be difficult to re-establish their populations because of their late maturation. This is why many organizations have been fighting for the rights of Whale Sharks among other sharks to ban finning internationally.

Why should you care?

The number one threat to ocean life is the shift of spacial habitats. Coral reefs produce about 20% of the oxygen in the earth’s atmosphere, as well as provide nutrients for the ocean. Whale sharks hunt smaller fish like groupers, and if they become too abundant then the coral reef will produce less oxygen and suffer. The Whale Shark maintains the ecosystem, preventing algae dominance by hunting predators of small herbivore fish. The food chain rests on the delicate balance of predator and prey. Without the Whale Shark’s contribution to this chain, life on sea and land will continue to decline.

What can you do to help?

1. Ethical Consumption:  Shark fin soup is a delicacy in many parts of the world, Including the USA. Some medicines are also made from shark products, as well as their oils are used to wax boats. If you want to protect these important sea creatures, refuse to consume anything made from Sharks.

2. Spread the word! Talk to family members and friends about what they’re doing to help the cause. Inform family on more sustainable delicacies they can enjoy instead of Shark Fin Soup.

3. Get Involved: Lastly, spend time signing petitions and getting involved in online spaces. If you can, donate whatever you can to organizations like The Human Society International, which aims to protect sharks from finning.

If there is a public demand for change, then change will come. With everyone’s help we can create new standards for the ocean and all of its inhabitants! With safer oceans we will continue to see the Whale Shark populations stabilize.