Clownfish in Australia: Where to Find Nemo

Hover over a bed of swaying tentacles and an orange fish with bright white bars wriggles up to meet you, fins whirring, refusing to give ground. It guards that anemone like a bouncer. Of all the fish on an Australian reef, this is the one every first-time snorkeller wants to find.

Australia's species range from the tropical Great Barrier Reef to subtropical islands off northern New South Wales, and their lives are stranger than any animated film: they live safely among stinging tentacles, they begin adult life as males, and their homes are now vulnerable to the same marine heatwaves that bleach coral.

Anemonefish species in Australian waters

Scientists generally call the group anemonefish. There are 28 species worldwide, and Fishes of Australia lists 13 from Australian waters. The ones divers most often meet:

- Orange clownfish (*Amphiprion percula*): bright orange with three white bars edged in thick black. Found on the Great Barrier Reef from Torres Strait to the Capricorn Group. - False clown anemonefish (*Amphiprion ocellaris*): almost identical, but with a taller dorsal fin, usually one more dorsal spine and little or no black edging on the bars. In Australia it lives in the far north-west, from Cape Leveque and offshore Western Australian reefs to Melville Bay in the Northern Territory. Nemo himself is drawn from this look-alike pair. - Barrier Reef anemonefish (*Amphiprion akindynos*): orange-brown with two white bars and a white tail. It ranges from the far northern Great Barrier Reef and Coral Sea south to at least Broughton Island in New South Wales. - Clark's anemonefish (*Amphiprion clarkii*): orange to almost black with three white bars, found from the Houtman Abrolhos and north-west reefs to Darwin and the northern Great Barrier Reef. It can live in all ten host anemone species. - Pink anemonefish (*Amphiprion perideraion*): peachy pink with one thin white bar behind the eye and a pale stripe along the back, found from Ningaloo Reef in the west to the Great Barrier Reef as far south as the Capricorn Group. - Wide-band anemonefish (*Amphiprion latezonatus*): dark brown with a very broad white mid-body bar. It is endemic to subtropical Australia, from southern Queensland to North Solitary Island and the Lord Howe and Norfolk Island region, and grows to 15 cm. - McCulloch's anemonefish (*Amphiprion mccullochi*): dark brown with a pale snout, found only in the Lord Howe region and living in a single anemone species, the bubble-tip anemone (*Entacmaea quadricolor*).

Others include the red-and-black anemonefish (*Amphiprion melanopus*), the spine-cheek anemonefish (*Amphiprion biaculeatus*), whose females can be two to three times the size of their mates, and the Australian anemonefish (*Amphiprion rubrocinctus*), endemic to north-western Australia from Ningaloo Reef to Groote Eylandt.

Living among stinging tentacles

Only ten species of sea anemone host anemonefish, and the partnership is mutual. The anemone's stinging tentacles shelter the fish from predators. In return the fish supply nitrogen and carbon to the anemone and the symbiotic algae living in its tissue, and chase off anemone predators such as butterflyfish.

How the fish avoid being stung has puzzled scientists since the partnership was first studied in the late 1800s. Researchers had proposed three explanations: a thicker mucus coat (Clark's anemonefish mucus is three to four times thicker than that of other reef fishes), a coat that mimics the anemone's own chemistry, or mucus that simply lacks the chemical trigger for the stinging cells.

A 2025 study in BMC Biology gives strong support to the third idea. Sugars called sialic acids are thought to help prime anemone stinging cells to fire. The researchers found anemonefish mucus carries far less sialic acid than that of a non-symbiotic damselfish, that the reduction is specific to the mucus, and that the anemones' own mucus has almost none. Young larvae are vulnerable; protection arrives around metamorphosis, as sialic acid levels fall. The authors describe it as a Trojan horse strategy: chemically, the fish looks like part of its host.

Born male: sex change and family life

Anemonefish first mature as males. Each anemone holds a monogamous breeding pair, often with a few smaller non-breeders, and size sets the pecking order. The female is the largest fish, her mate the second largest. If she dies or disappears, the male changes sex to become the new breeding female, and the biggest non-breeder steps up as the breeding male. Biologists call this protandrous hermaphroditism.

When breeding, the male clears a patch of bare rock beside the anemone, the female lays her eggs there, and the male guards and fans them until they hatch. At Julian Rocks off Byron Bay, researchers found female wide-band anemonefish spawning up to three times a month in summer, with clutches of roughly 800 to 3,870 eggs.

Where to see clownfish in Australia

Great Barrier Reef. Anemonefish are one of the reef's "Great Eight" icons, and at Lady Elliot Island the resort's reef guides report an abundance of them, with the search starting in the island's lagoon. Lady Elliot is also known as the home of the manta ray, with aggregations in the cooler months, so pair your search with our guide to manta rays in Australia.

Northern New South Wales. The Solitary Islands Marine Park off Coffs Harbour has some of the densest beds of host anemones on Earth. A 2009 Southern Cross University survey around North Solitary Island covered three species: the Barrier Reef, wide-band and red-and-black anemonefish. The local research group SURG notes the bubble-tip anemone reaches its highest concentrations at North Solitary Island's Anemone Bay, and that the Barrier Reef anemonefish is common at all the park's offshore islands, peaking at North Solitary.

Lord Howe Island. Lord Howe Island is the place to find McCulloch's anemonefish, which lives nowhere else in the world. About three-quarters of the island's population lives inside the lagoon.

Western Australia. The Australian, pink and orange skunk anemonefish are all recorded from Ningaloo Reef, and Clark's anemonefish from the Houtman Abrolhos.

Did Finding Nemo empty the reef?

Not in the way the headlines suggested. A 2017 study of the "Nemo effect" in Fish and Fisheries found that import and export figures showed little evidence of fans buying wild-caught clownfish in the 18 months after the 2003 film's release. The authors argued that emotive but scientifically uninformed media coverage can do conservation more harm than good.

Collection still matters locally. A 2008 survey of anemonefish in two regions of the Great Barrier Reef Marine Park found the highest densities on reefs closed to fishing and aquarium collecting, both in the Keppel Islands and in Far North Queensland, suggesting collection was compounding the damage from bleaching. Removing anemones leaves the fish homeless, and removing the fish leaves anemones exposed to predators. Several Australian species are now bred in captivity, which gives aquarists an alternative to wild-caught fish.

At North Solitary Island, protection has worked. The Southern Cross University survey found that Barrier Reef anemonefish had increased by 133% since the mid-1990s, and bubble-tip anemone density by more than 500% at some sites, inside a no-take sanctuary zone.

When the anemone bleaches

Host anemones carry symbiotic algae just as corals do, and under heat stress they bleach. A global survey published in PLOS ONE confirmed bleaching in seven of the ten host species at 10 of 19 locations. Overall only 3.5% of nearly 14,000 anemones were bleached, but during five major bleaching events the figure reached 19-100%, and in some species bleaching shrank anemones and reduced their numbers. Some sites and deeper water appeared to act as refuges.

On the Great Barrier Reef, the Keppel Islands survey found no anemonefish or anemones on or near bleached corals. The 2016 marine heatwave bleached anemones along with corals, and a study at Lizard Island reported severe consequences for anemonefishes and their hosts. If water cools quickly, bleached anemones can regain their algae and survive; if heat persists, they die. In Japan in 1998, mass anemone deaths led to local extinctions of anemonefish. Anemonefish larvae can even smell the difference and avoid settling in bleached anemones.

Diving and snorkelling with anemonefish responsibly

- Hover, don't hassle. The Reef Authority asks visitors to observe animals from a distance without chasing or feeding them. Hold position above the anemone and the pecking order plays out in front of you; Lady Elliot's guides say you can sometimes even hear the fish chattering. - Keep hands and fins off. Avoid touching the anemone, the surrounding coral and the bare rock beside it, where a male may be guarding eggs. - Read the warning signs. Anemonefish defend their anemones fiercely, so a fish darting at your mask is defending its home. Back off and let it settle. - Take only photos. Collecting is banned in sanctuary (no-take) zones, and the North Solitary anemone beds sit inside one.

Do that, and Nemo's relatives will still be holding their ground when the next diver arrives.

Sources

- Fishes of Australia: Amphiprion (anemonefishes) - Roux et al. (2025) Anemonefish use sialic acid metabolism as Trojan horse to avoid giant sea anemone stinging, BMC Biology - Militz & Foale (2017) The "Nemo Effect": perception and reality of Finding Nemo's impact on marine aquarium fisheries - Jones, Gardner & Sinclair (2008) Losing "Nemo": bleaching and collection appear to reduce inshore populations of anemonefishes - Hobbs et al. (2013) Taxonomic, spatial and temporal patterns of bleaching in anemones inhabited by anemonefishes, PLOS ONE - Southern Cross University: Anemones find the ideal home - Solitary Islands Underwater Research Group: Barrier Reef anemonefish - Hobbs & Frisch (2016) Saving Nemo: how climate change threatens anemonefish and their homes, Australian Geographic

Header photo: Two Barrier Reef anemonefish (Amphiprion akindynos) in their host anemone, Great Barrier Reef off Cairns, Queensland. by Leonard Low, CC BY 2.0, via Wikimedia Commons.