The Basking Shark and the Whale Shark belong to the families Cetorhinidae and Rhincodontidae respectively, and are among the largest fishes in the ocean. The Basking Shark, reaching lengths of up to 40 feet, and the Whale Shark, which can grow up to a staggering 60 feet, are indeed awe-inspiring sights.
Despite their formidable size, both species are known for their docile nature and plankton-based diet. Continue reading to learn more about these two gentle giants of the sea, and explore their distinct traits, behaviors, and the ecological roles they play in our oceans.
Credit: Greg Skomal (left), Matthew T Rader (right)
Basking Shark vs Whale Shark: Main Differences
Here are the main differences between the basking shark and the whale shark:
Appearance: Basking sharks are grey/brown with mottled skin and a particularly large mouth. Whale sharks are dark grey, with white spots, and have a large mouth too, to help filter feeding. Basking sharks resemble more the stereotypical shape of a shark, whereas whale sharks are flatter in shape, at their heads with the mouth at the front of their heads (than the underside).
Size: Basking sharks can reach 26 feet in length, compared to nearly 62 feet for the much longer whale shark.
Habitat: basking sharks live everywhere, typically traveling thousands of kilometers to find plankton to feed, whereas whale sharks typically live in tropical oceans.
Diet: Both sharks are filter feeders, using their large mouths to swim and collect small creatures, such as zooplankton, small fish, fish eggs, and invertebrates.
Life span: Basking sharks can live to around 50 years, whilst whale sharks can live to nearly 130 years.
We’ll explore these differences and interesting facts about each shark more below.
Who Would Win?
In a hypothetical “who would win” scenario between a Basking Shark and a Whale Shark, it’s important to remember that both these species are gentle giants of the ocean, known for their docile nature and plankton-based diet. They are not typically aggressive or territorial, and a confrontation between them is highly unlikely.
However, if we were to consider their respective sizes and physical characteristics, the Whale Shark, being the larger of the two, might have an advantage in terms of sheer size. But then again, the Basking Shark, with its large mouth and gill rakers designed for efficient filter feeding, could potentially outcompete the Whale Shark when it comes to feeding on dense patches of plankton.
Ultimately, it’s essential to understand that these magnificent creatures are not built for combat against each other. Instead, they are perfectly adapted for their unique ecological roles as some of the ocean’s largest filter feeders. Their ‘winning’ attributes lie in their contribution to maintaining the health and balance of marine ecosystems.
Basking Shark
The basking shark is a large shark, considered to be the largest living shark after the whale shark. Its name comes from its habit of swimming to the surface of the water and appearing to bask in the sunlight.
These sharks are usually solitary animals but have been known to congregate around the best patches of zooplankton. In these situations, social behavior has been noted. The shark is the only living member of the Cetorhinidae family.
The basking shark can reach lengths of twenty-six feet. It’s usually grey-brown with mottled skin. It also has a distinctive large, bulbous head. The sharks also have a caudal fin that is distinct in its crescent shape. The average weight of an adult basking shark is around 4.65 tons.
One of its unique features is its large, arching dorsal fin, which often protrudes above the water when it’s feeding near the surface, making it easily identifiable. It also has long, filamentous gill slits that almost encircle its head, allowing efficient filter feeding. Its caudal (tail) fin is crescent-shaped and quite large, contributing to its slow but powerful swimming style.
Marine biologists have discovered basking sharks have strong muscular hearts that probably help generate high blood pressure and flow. The basking shark muscles are warmer than the water they swim in.
The basking shark has a remarkable conical-shaped snout and gill slits that extend from the top to the bottom of its head. The sharks also have around 100 teeth per row.
Habitat
The basking shark is found around the world in temperate oceans and is known as a cosmopolitan migratory species. These sharks move thousands of kilometers during the various months of the year as they seek out the largest patches of plankton. Some migrate south during the winter. They’ve been seen around Massachusetts, the Amazon River, the Mediterranean Sea, the North and South Atlantic, and other varied areas of the Earth’s oceans.
Usually, during the colder months, they move down to deeper depths, around 3,000 feet or 900 meters.
Basking Sharks reproduce through a method known as ovoviviparity, where eggs develop and hatch within the mother’s body, resulting in live birth. The gestation period is believed to be quite long, possibly up to three years.
At birth, Basking Shark pups are relatively large, measuring around 5-6 feet in length. However, many details about their mating behaviors and breeding grounds remain unknown due to the difficulties of studying these creatures in their natural habitats.
Diet
The basking shark is a filter feeder. This means that it opens its mouth and strains its food through a filtering structure. The basking shark feeds on zooplankton, small fish, copepods, and invertebrates in the water. It uses its gill rakers when it swims forward and opens its mouth. It can filter around 500 short tonnes of water per hour, according to Proceedings of the Royal Society.
Reproduction
Basking Sharks reproduce through a method known as ovoviviparity, where eggs develop and hatch within the mother’s body, resulting in live birth. The gestation period is believed to be quite long, possibly up to three years.
At birth, Basking Shark pups are relatively large, measuring around 5-6 feet in length. However, many aspects of their reproductive behaviors remain a mystery due to the challenges of studying these creatures in their natural habitats.
Threats
Basking Sharks face numerous threats, primarily from human activities. They are often targeted for their fins and liver oil, and are also at risk from bycatch in fisheries. Their slow speed and habit of feeding near the surface make them particularly vulnerable to boat strikes.
The basking shark has unfortunately become an endangered species, according to the IUCN Red List. The population in the Pacific Ocean is considered the most threatened.
Various conservation measures have been implemented to protect them.Efforts are also being made to reduce bycatch and protect their habitats. Despite these measures, their populations are slow to recover due to their long gestation period and low reproduction rate.
Whale Shark
The whale shark is a slow-moving shark that is the largest living shark species, followed by the basking shark and is the only living member of the genus Rhincodon.
The shark’s mouth contains 300 rows, or more, of tiny teeth and 20 filter pads that they use to filter feed (like the basking shark). Its mouth is at the front of its head rather than the underside. This is uncommon to sharks, according to Species Fact Sheet, Rhincodon typus.
The shark’s head is large and flat, with small eyes and five large pairs of gills. These sharks are also noted for their dark grey skin that’s covered with pale grey or white spots and stripes. These are unique to each individual and set the species apart from other sharks. It also has three ridges along its sides that start behind the head and end at the caudal peduncle or the tapered region behind the dorsal and anal fins.
The Whale Shark’s fins play essential roles in its locomotion and stability. The dorsal fin aids in stabilization, preventing the shark from rolling or sinking. The pectoral fins on either side of the body help with steering and lift, while the crescent-shaped caudal fin, or tail, propels the shark through the water. The pelvic fins assist in stabilization and, in males, double as reproductive organs called claspers. Lastly, the anal fin located just before the tail contributes to swimming stability. Each fin is crucial for the Whale Shark’s navigation, balance, and feeding.
Habitat
The whale shark lives in open waters, usually in tropical oceans, such as the Indian Ocean. There have only been a few sightings of the shark in water below 70 degrees F or 21 degrees C. Migration is key to the whale shark, following the warm waters all year round. The main two populations of sharks are in the Atlantic and the Indo-Pacific. The latter is by far the largest, with 75% of the whole population inhabiting these tropical areas.
The whale is known to gather in large numbers during certain months of the year. One of the most significant of these gatherings was off the coast of Mexico, in Yucatan. Four hundred whale sharks were sighted. Magical events like this have sparked great human interest and ecotourism.
Diet
The whale shark, as noted above, is a filter feeder. This means that it feeds on small ocean-dwelling creatures like kill, plankton, fish eggs, and more. Christmas Island red crab larvae are also popular. Sometimes, the sharks also eat small fish or squid, according to BBC News.
They are only one of three known species of filter-feeding sharks. (The basking shark and the megamouth shark are the others.) Scientists have estimated that a young whale shark can eat around 46 pounds of plankton a day, according to The Shark Research Institute.
Both the basking and whale shark are gentle giants, posing little threat to humans and divers due to their docile temperament and lack of teeth.
Reproduction
Similar to Basking Sharks, Whale Sharks also reproduce through ovoviviparity. A remarkable discovery was made when a pregnant female captured in 1995 was found to have around 300 embryos at different stages of development, suggesting that Whale Sharks can give birth to a large number of pups at once.
Newborn Whale Shark pups range from 1.5 to 2 feet in length. As with Basking Sharks, much about their reproductive behaviors and breeding grounds remains a mystery.
Threats
Whale Sharks also face significant threats from human activities. They are hunted in some countries for their meat, fins, and oil. Accidental capture in fishing gear is another major threat. Additionally, boat strikes, pollution, and habitat degradation pose significant risks.
Conservation efforts for Whale Sharks include protective legislation in many countries. The whale shark is currently listed as endangered by the IUCN. Due to this, there are now conservation efforts taking place to stabilize the population. There are still many other issues, such as oil spills and the Chinese whale shark fin and skin industry encouraging illegal hunting.
Several areas known for Whale Shark aggregation have been designated as protected areas. The Philippines is one of the leading countries in this area. They have minimized and banned all fishing and commercial activity surrounding the animals.
Ongoing research and satellite tracking programs are also helping to improve our understanding of their behaviors and migration patterns, informing more effective conservation strategies.
Ocean Insights: Hear From Our Experts
By Hamna Faizan
Marine Life Researcher and Lecturer, with an MSc in Zoology
FAQs
Do basking sharks attack humans?
They are large enough to eat a human, but human beings are not something the sharks are truly interested in eating. They prefer plankton. There have been reports of incidents in which basking sharks capsized a boat off the coast of Scotland. But, incidents involving humans are incredibly rare. As a docile creature with a filter-based feeding system, it is unlikely to happen in the future.
Why are Basking Sharks often seen ‘basking’ on the ocean surface?
Despite its name, the Basking Shark isn’t basking in the sun. It feeds near the surface, which makes it appear as if it’s basking. This behavior also allows them to take advantage of dense plankton blooms that often occur near the surface.
What’s unique about the Whale Shark’s skin?
The Whale Shark’s skin is not only incredibly thick, up to 15cm in some places, but also adorned with a pattern of white spots and stripes, unique to each individual, much like human fingerprints. This distinctive pattern helps scientists identify and track individual sharks.
Is there a shark bigger than a whale shark?
The simple answer is no. The whale shark is considered the largest living shark to grace the earth’s oceans. The largest-ever whale shark was a staggering 18.8 m long.
How do Whale Sharks feed given their tiny teeth?
Despite having thousands of tiny teeth, Whale Sharks feed by filter-feeding. They suck in a mouthful of water, close their mouth and expel the water through their gills, trapping food particles inside. This allows them to feed on microscopic plankton, despite being one of the largest creatures in the ocean.
