On a shallow coral reef in the southwest Pacific Ocean, a small colony of giant carpet anemones grow in a bed of sea grass, their thin, tubular nematocysts gently waving with the water's currents. Despite their innocent and soft appearance, these anemones create a hostile environment for much of the surrounding sea life. Hundreds of venomous tentacles keep most marine wildlife at bay, threatening to deliver an excruciatingly painful sting to any animal that dares to swim too near. This evolutionary defense mechanism serves a dual purpose: it repels unwelcome species of fish while welcoming Orange Clownfish.
In warm waters throughout the eastern Indian and western Pacific Oceans, anemone and Orange Clownfish have forged a unique symbiotic relationship. Unlike other species of aquatic animals, clownfish can quickly establish immunity to anemones' venom early in life. Upon its first encounter with anemone, the tiny fish will initially approach the organism with caution, only touching the tentacles with its fins. This contact immediately causes a chemical reaction as the Orange Clownfish begins to develop a protective mucous coating. Within a matter of minutes or hours, the fish freely swims through the anemone's nematocysts with no repercussions.
For the duration of their lives, Orange Clownfish will not only use anemone as their protectors, but also their homes. Any venture into the open ocean is dangerous; only measuring between 6 and 11 centimeters (2.4 and 4.3 inches), adults are not only small, but also defenseless and poor swimmers. When predators like wrasses, damselfish, and brittle stars lurk in the vicinity, Orange Clownfish have a singular instinctual reaction: dart back into the friendly fronds of its shelter.
In return for protection, these biologically privileged inhabitants perform several invaluable services for their hosts. When algae and zooplankton contaminate the anemone, Orange Clownfish act as cleaners while filling their own stomachs. Conveniently, the subsequent fish fecal matter is food for the anemone. Furthermore, by living amidst the nematocysts, the fish promote oxygenation for their host organism.
Despite its nickname, Amphiprion percula does not bear any particularly funny physical features. Slender and ovular in shape, the vividly orange fish bears three distinctive white stripes: one behind its eyes, one down the middle of its body (with a slight anterior projection on both sides), and one at the base of the caudal fin. All three of these bars are bordered by black lines.
What this species lacks in slapstick comedy, however, it makes up for in unique biological attributes. As protandrous hermaphrodites, all Orange Clownfish are born male - and most will remain that way for their entire lives. Whether or not an individual ever develops female reproductive properties depends entirely on how large it ultimately grows.
Orange Clownfish thrive in small groups that abide by a strict hierarchy based on physical size, which in turn directly affects the gender of its members. The largest fish undergoes a sex change and becomes the sole female in the group. The next largest fish, retaining his original gender, holds exclusive breeding rights with the sole sexual counterpart. Between zero and three non-breeding males round out the group, all rendered incapable of breeding by their non-functional reproductive organs. These non-breeders contribute nothing, serve no beneficial role, and reap no benefits other than the shelter of an anemone. Nevertheless, this protection cannot be understated, as it is the main reason the non-breeders accept their diminutive status; for Orange Clownfish, it is live together or die alone.
As part of a group, there is also the opportunity for upward social mobility - but only death can shift the balance of power. If a large non-breeder dies, his smaller companions become that much closer to gaining reproductive privileges. If the mating male dies, the largest non-breeder develops reproductive organs and assumes his role. If the female dies, the mating male will change its sex to female - which also makes the Orange Clownfish a sequential hermaphrodite - and the largest non-breeding male will become elevated to new mate.
Despite wielding exclusive mating rights, the largest male will still court the female, chasing her around the reef, displaying his fins, and playfully nibbling her. Orange Clownfish will mate at any point during the year, but spawning always correlates with the lunar cycle; a full Moon means prime mating time. Once impregnated, both female and male prepare a nest in close proximity to their home anemone - usually a flat or protected rock surface - allowing them an easy escape if necessary.
When the nest is ready, the female will wait until nightfall to lay her eggs, depositing anywhere between 400 and 1500 eggs while the male trails behind fertilizing the eggs. Over the ensuing week, the male is charged with watching over the nest and nurturing the eggs by repeatedly fanning them to provide adequate oxygen circulation. If he spots a rotting or damaged egg in the bunch, he will eat it before the healthy eggs become afflicted with a potentially spreading ailment or problem. When the week is over, in the thick of night, the eggs hatch.
Once liberated from their eggshells, the miniscule Orange Clownfish larvae make a straight swim for the ocean's surface. For the next week, these translucent larvae move at the mercy of the currents, consuming plankton throughout the ride. When the still tiny specimens sink back to the watery depths, the larval stage ends quickly; within a day, the larva transforms into a juvenile fish, fully colored orange and white, intent on finding a shelter as soon as possible.
For those Orange Clownfish that survive their first week of existence, life does not get any easier - especially for the smaller recruits. Most anemones are already occupied, and group members do not welcome recruits kindly. Even when a new member joins a group and finds a home, gaining protecting from the outside ocean through the nematocysts of the anemone, the struggle continues.
Constantly jockeying for social status, Orange Clownfish seek to thwart any challenger with the potential of elevating higher in the group ranks. This competition drives group members to fight with each other, as each male will attempt to the stunt the growth of those smaller than him. It is a cycle of trickle-down bullying that leaves the smallest group member with no power and no one to hit. Despite these hardships, there is an important silver lining to remember: certain fighting trumps certain death, and the smallest Orange Clownfish in a group is still an Orange Clownfish with an anemone - a home.
A male Orange Clownfish and its mate, a larger female Orange Clownfish are shown amidst the protection of the stinging tentacles of a sea anemone (Heteractis magnifica). In the distance another individual sea anemone can be seen, though this one without resident Clownfish being detectable.
6-11 centimeters (2.4-4.3 inches)
Warm, shallow coral reefs close to shoreline in Pacific Ocean, Indian Ocean, Great Barrier Reef, and southeast Asian and Japanese waters
25-28 degrees Celsius (77-82 Fahrenheit)
Algae, zooplankton, worms, and small crustaceans
The Orange Clownfish is often understandably confused with its close relative, the Ocellaris Clownfish (the subspecies made famous by Pixar's universally beloved title clownfish character, Nemo). The main distinguishing features between the two types are subtle: the Orange subspecies has 10 spines on its first dorsal fin while the Ocellaris has 11 and no black borders on its stripes.
Despite their competitive personalities in the wild, Orange Clownfish are considered popular aquarium fish and docile in captivity.
Orange Clownfish almost exclusively colonize Heteractis magnifica - known as magnificent sea anemone or Ritteri anemone - and Stichodactyla gigantean - known as giant carpet anemone.
There are 28 subspecies of Clownfish in the world.