Wildlife Guide · Tropical and warm-temperate oceans worldwide & Seasonal aggregation sites off Mexico, the Philippines, Australia and East Africa

Whale Shark

Rhincodon typus (Smith, 1828) — family Rhincodontidae

The largest fish on Earth, and it eats some of the smallest things in the sea.

Endangered — the largest fish alive, and a filter feeder

Whale shark with white checkerboard spots swimming in blue tropical water

Image: AI-generated educational wildlife portrait — World Animal Rescue Network · AI visualisation, not a photograph

In brief

The whale shark (Rhincodon typus) is the largest fish on Earth at up to around 18 metres, a filter feeder that eats plankton and small fish, and is listed as Endangered.

By the WARN Research & Conservation TeamChecked against IUCN Red List & CITES sourcesLast updated July 2026

The whale shark is the largest fish alive, reaching around 18 metres, and it feeds almost entirely on plankton and small fish. It is a shark, not a whale — the name describes the size and the filter-feeding habit rather than any relationship to cetaceans. Each whale shark carries a unique pattern of pale spots and stripes behind the gills. Researchers photograph that pattern and identify individuals using software originally written to map star fields, which has allowed the same animals to be tracked across oceans and decades.

~18 m

Maximum recorded length — the largest fish alive

~3,000

Tiny teeth, which play no part in feeding

Unique

Spot patterns identify individuals, mapped with star-field software

~30 yr

Estimated age at maturity — very slow to reproduce

Figures sourced from IUCN Red List — Rhincodon typus, CITES Appendices .

Whale Shark: Quick Facts

Vital statistics and key facts about the Whale Shark
Maximum length	~18 m
Diet	Plankton, fish eggs, krill and small fish
Teeth	~3,000, each a few mm, unused in feeding
Identification	Unique spot pattern behind the gills
Age at maturity	Around 30 years
Trade status	CITES Appendix II

Scientific Classification

Scientific classification of the Whale Shark
Kingdom	Animalia
Phylum	Chordata
Class	Chondrichthyes
Order	Orectolobiformes
Family	Rhincodontidae
Genus	Rhincodon
Species	Rhincodon typus

Conservation Status

IUCN Status: Endangered
Population: Unknown; substantial decline documented across recent generations
Trend: Decreasing
Assessed: 2016
CITES: Appendix II

Late maturity and low reproductive output mean adult losses have an outsized effect. Well-regulated tourism can support protection; unregulated tourism adds to the pressure.

Did you know?

Individual whale sharks are identified using an algorithm written to match star patterns in astronomical photographs.

Key Facts: Whale Shark

Whale sharks are fish, not whales — the name reflects size and filter feeding.
They eat plankton, fish eggs and small fish, filtering water through gill rakers.
Spot patterns are individually unique and are matched using astronomy software.
Late maturity, around 30 years, makes populations extremely slow to recover.
They are Endangered, hit by ship strikes, fishing and unmanaged tourism.

Filter feeding at scale

A whale shark feeds by opening its enormous mouth and either swimming through plankton or holding position and actively suctioning water in. Gill rakers strain out plankton, fish eggs, krill and small fish, and the water passes out through the gills. It has around 3,000 teeth, each only a few millimetres long, and they play no role in feeding at all. Their function, if any, is unresolved — a good illustration of how much about even the largest fish remains unknown.

Identified by starlight software

The pattern of pale spots and stripes behind a whale shark's gills is unique to the individual and stable for life. Researchers photograph it and match it using an algorithm adapted from software written to identify star patterns in astronomical images. That method turned whale shark research into a global collaboration: photographs from tourists and divers feed public databases, and individual sharks have been re-identified years later and thousands of kilometres away.

Slow lives, sharp declines

Whale sharks are thought to mature at around 30 years and to live far longer. Slow maturity and low reproductive output mean that losing adults has a disproportionate effect, and populations cannot rebound quickly from fishing or bycatch. The species is listed as Endangered. Targeted fishing has been banned in many countries but continues in some, and bycatch in tuna purse seines, ship strikes at aggregation sites and entanglement all remove animals from a population that replaces them slowly.

Tourism: the double edge

Predictable seasonal aggregations support significant whale shark tourism, which gives coastal communities an economic reason to protect the animals — a live shark is worth far more repeatedly than a dead one once. Badly managed, though, tourism harms them. Boat strikes, crowding, touching and provisioning to hold sharks at a site all cause measurable stress and injury. Well-run operations enforce minimum distances, no touching, no flash and boat exclusion zones, and those rules are the difference between tourism that protects the species and tourism that erodes it.

What WARN Does

WARN publishes free, sourced species education including where wildlife tourism helps and where it harms. Whale sharks are among the clearest cases: the same activity can fund protection or injure the animals, and the deciding factor is whether operators follow distance and handling rules that visitors are in a position to insist on.

If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.

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How can I help save the whale shark?

There are three practical things that make a real difference for the whale shark — and the first is the one that funds everything else.

Fund frontline rescue

Back the partner-led teams, veterinary care and protection that reach whale sharks where the need is greatest — WARN channels donations straight to that work.

Ease the pressures

Avoid the wildlife trade and souvenirs, never buy wild animals as pets, and choose sustainable, habitat-friendly products — the threats behind the whale shark's decline fall when demand does.

Spread the word

Share accurate, sourced information about the whale shark. Wider awareness is what turns concern into lasting protection.

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Whale Shark: Frequently Asked Questions

How can I help save the whale shark?

The most effective way to help the whale shark is to fund the frontline rescue and habitat protection that keeps the species alive — WARN channels donations to partner-led teams working where the need is greatest. You can also ease the pressures behind its decline by avoiding the wildlife trade and souvenirs, never buying wild animals as pets, and choosing sustainable products, and by sharing accurate information to build wider support. See the ways to help below, or support WARN's Support Habitat Protection.

Is a whale shark a whale or a shark?

A shark — the largest fish alive. The name refers to its whale-like size and filter-feeding habit, not to any relationship with whales, which are mammals.

How big do whale sharks get?

Around 18 metres at the largest verified sizes, and roughly 20 tonnes. Reports of considerably larger animals circulate but are generally unverified.

Are whale sharks dangerous?

No. They are filter feeders with around 3,000 tiny teeth that play no role in feeding. They pose no threat to swimmers, though their size means an accidental tail strike from a startled animal can injure someone who is too close.

How are individual whale sharks identified?

By the pattern of pale spots behind the gills, which is unique to each animal and stable for life. Researchers match photographs using an algorithm adapted from software built to identify star patterns, and public photo databases let tourists contribute records.

Are whale sharks endangered?

Yes, the IUCN lists them as Endangered. They mature at around 30 years, so populations recover very slowly from targeted fishing, bycatch in tuna fisheries, ship strikes and entanglement.

What do whale sharks eat?

Whale Sharks eat Plankton, fish eggs, krill and small fish. The whale shark (Rhincodon typus) is the largest fish on Earth at up to around 18 metres, a filter feeder that eats plankton and small fish, and is listed as Endangered.

Where do whale sharks live?

Whale Sharks live in Tropical and warm-temperate oceans worldwide, Seasonal aggregation sites off Mexico, the Philippines, Australia and East Africa. The whale shark (Rhincodon typus) is the largest fish on Earth at up to around 18 metres, a filter feeder that eats plankton and small fish, and is listed as Endangered.

How long do whale sharks live?

Whale Sharks typically live Around 30 years. The whale shark (Rhincodon typus) is the largest fish on Earth at up to around 18 metres, a filter feeder that eats plankton and small fish, and is listed as Endangered. Wild and captive figures can differ; use the sources listed on the guide for the underlying studies.

Sources & References

Population figures, conservation status and biological facts on this page are drawn from authoritative scientific and intergovernmental sources.

Terms used on this page

Plain-English definitions, from our wildlife and conservation glossary.

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