Whale shark

What it is

This enormous shark is the biggest fish alive today. Its body is dark grey on top with a white belly covered in unique pale spots and stripes. The head is broad and flat, featuring a huge mouth at the front rather than underneath. Inside, it has over three hundred rows of tiny teeth and twenty filter pads. These structures help strain food from the water. The skin is thick, hard, and rough. Three ridges run along its sides. Two dorsal fins sit far back on the body. The tail has a larger upper lobe. Despite its size, it is not aggressive toward humans.

Where it lives

These sharks roam all tropical and warm-temperate seas. They typically stay between thirty degrees north and thirty-five degrees south latitude. They avoid waters colder than twenty-one degrees Celsius. Tracking shows they move thousands of kilometres to find food. Major groups live in the Indo-Pacific region. Another group lives in the Atlantic Ocean. They visit specific coastal areas like Ningaloo Reef in Australia and the Yucatan Peninsula in Mexico. Some have been seen near Canada and Japan. Deep dives below five hundred metres are common during their travels.

How it lives

They feed by filtering plankton, krill, and small schooling fish like sardines. A single shark can process six thousand litres of water each hour. This active feeding strategy supports their massive size. They are highly migratory, following seasonal food sources. Aggregations form at predictable coastal sites. They exhibit vertical movement patterns, swimming near the surface before diving deep. Their eyes have special pigments adapted for blue light in deep water. In shallow, bright water, they deactivate this pigment to see clearly. They can recover from injuries and regenerate small fin sections.

Breeding and life cycle

Reproduction details remain poorly understood. Mating has been filmed off Ningaloo Reef and St Helena. Pups have never been observed being born in the wild. Growth studies suggest late sexual maturity, occurring around twenty-five years of age. Males grow faster initially but reach a smaller maximum size than females. Females may mature at similar or larger sizes. Vertebral growth bands indicate annual layer formation. This method helps estimate age, showing individuals can live up to one hundred and thirty years.

Fish and people

Ecotourism drives interest in these gentle giants. Divers swim alongside them at aggregation sites. However, tourism levels have grown unsustainable in some areas. Historically, they were targeted for fishing. Bycatch in other fisheries poses a significant threat. Collisions with large ships also cause mortality. Conservation efforts aim to protect their habitats. Cultural significance varies across regions where they appear. Research programmes study their migration and genetics. The complete genome was published in two thousand seventeen.

Status and threats

The International Union for Conservation of Nature lists this species as Endangered. Populations have declined by more than fifty percent over the last seventy-five years. Primary threats include targeted fishing and accidental bycatch. Ship strikes add to the mortality rate. Habitat degradation affects feeding grounds. Protection measures are critical for recovery. Scientific monitoring tracks population trends. Public awareness campaigns highlight conservation needs. Sustainable tourism practices are encouraged to reduce stress on aggregations.

Relatives and look-alikes

It is the only living member of the family Rhincodontidae. An extinct species, Rhincodon ferriolensis, lived in Europe. Before nineteen eighty-four, it was classified under Rhiniodon. Other ancient shark lineages share similarities in evolutionary history. Fossil teeth date back to the Late Oligocene. Modern relatives include other carpet sharks. Confusion sometimes arises with cetaceans due to size, but it is a fish. Distinctive spot patterns help identify individuals within populations.

Questions people ask about Whale shark

Good reading and sources

• BBC NEWS | Science & Environment | Shark-cam captures ocean motionBBC, Article
• Drive to conserve whale sharkThe Hindu, Article

• Whale shark on WikipediaEncyclopedia
• More photos on Wikimedia CommonsPhotos
• Wikidata recordOpen data