The symbiosis between A. percula and its host anemone serves as an effective anti-predation measure. Protected within the tentacles of the sea anemone, A. percula belongs to a unique group of fishes that are not stung by the nematocysts. It is believed that a thick mucous layer cloaks the fish from detection and response by anemone tentacles (Rosenberg and Cruz, 1988). Fish species lacking in this physiological adaptation are captured and devoured by the sea anemone. It is no surprise, then, that A. percula has very few predatory foes as adults. Presence of danger immediately elicits a response to seek shelter deep within its host. Although adults are relatively safe from predation, the eggs of A. percula are susceptible and must be guarded by the dominant male. The most common day predators are wrasses (family Labridae) and other damselfishes (family Pomacentridae). Night predators of eggs are generally not fishes but invertebrates like brittle stars (Ophiotrichidae, Ophiochimidae, and Ophiodermatidae) (Arvedlund et al., 2000).
Known Predators:
A. percula can grow to 110 mm in length and is often distinguished by three white vertical bars on a bright orange body. The anterior white bar occurs just behind the eye; the middle bar bisects the fish; the posterior bar occurs near the caudal fin. An anterior projecting bulge further characterizes the middle bar. In addition to the white coloring, black edging outlines each fin with varying thickness (Fautin and Allen, 1992; Grant, 1999). Although A. percula’s vibrant colors are eye catching, it is easily confused with Amphiprion ocellaris (false clown anemonefish). One may distinguish the two by counting the number of dorsal-fin spines. A. percula usually has 10 dorsal-fin spines, while A. ocellaris usually has 11. Also, the latter never has thick black margins outlining the fins (Fautin and Allen, 1992)
There is no difference in color patterns among sexes. Nonetheless, dimorphic variation is present, since the female is larger than the male. Polymorphism, although present in other species of anemonefishes, does not occur in A. percula. Such is the case with melanistic (black pigmentation) variation in some anemonefish species. This is generally absent in A. percula (Fautin and Allen, 1992).
Range length: 110 (high) mm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: female larger
There is very little longevity data for many species of anemonefishes. However, some are recorded to have lived at least 6-10 years in nature. In captivity, the record is 18 years for Amphiprion frenatus and Amphiprion perideraion.
Average lifespan
Status: wild: 6-10 years.
Range lifespan
Status: captivity: 18 (high) years.
Typical lifespan
Status: wild: 6 to 10 years.
Perception Channels: tactile ; chemical
The depletion of coral reef habitats and marine aquarium fishes has presented a relatively new market in aquaculture. It is possible to rear A. percula in controlled conditions (Gordon et al., 2000), and it may eventually play a significant role in maintaining stable populations. At present, this species is not threatened or endangered.
US Federal List: no special status
CITES: no special status
After incubating for 6-7 days, the eggs of A. percula are ready to hatch. Just before then, however, the embryo is visible through the transparent egg membrane. The two noticeable features at this stage are the silvery pupils contained within the large eyes and the red-orange yolk sac (Fautin and Allen, 1992). After hatching, the larva is about 3-4 mm total length and transparent except for the eye, yolk sac, and a few scattered pigments. The newly hatched individual initially sinks to the benthic environment but quickly swims to the upper surface of the water column using a process called phototaxis. Essentially, the larva is able to orient itself using the shine from a moonlit night. At this point, the larva spends a week floating among the plankton and is passively transported by ocean currents (Fautin and Allen, 1992). The larval stage of A. percula ends when the young anemonefish settles to the sea bottom approximately 8-12 days after hatching (DAH). Compared to other coral reef species, this is a relatively short period (Wellington and Victor 1989).
The juvenile stage of A. percula is characterized by a rapid development of color schemes. The white barring pattern that is unique to this species begins to form around 11 DAH and may correspond to the fish’s first association with its host anemone (Elliott et al., 1995). Consequently, contact with the anemone stimulates A. percula to produce its protective mucous coat (Elliott and Mariscal, 1996) (See Behavior section for a complete elaboration on acclimation and protection from anemone nematocysts). The entire metamorphosis from larva to juvenile is usually completed in a day (Fautin and Allen, 1992).
Development from juvenile to adult is highly dependent on the social hierarchy of the “family group.” Each host anemone is often occupied by a mating pair plus two to four smaller fish (Fautin and Allen, 1992). Aggression between the dominant female and her mate is minimal, thereby causing little expenditure in energy. Each male, however, bullies and chases the next male of smaller successive size until the smallest individual is driven away from the host anemone. As a result, energy that could be used for growth is instead appropriated for competitive encounters. The adult pair essentially stunts the growth of juveniles (Myers, 1999).
Like other anemonefishes, the uniqueness of A. percula development lies in adult metamorphosis from male to female (protandrous hermaphroditism). All anemonefishes are born as males (Wood and Aw, 2002; Fautin and Allen, 1992; Rosenberg and Cruz, 1988), and the largest of the group reverses sex to become the dominant female. The second largest male subsequently becomes the dominant male. In instances when the female dies, the dominant male reverses sex and all other subordinate males move up in the hierarchical ladder.
Development - Life Cycle: metamorphosis
None known
A. percula and other anemonefishes are some of the most colorful fish species available for the aquarium trade. They also demonstrate interesting behaviors and are easily adaptable to captivity (Fautin and Allen, 1992). Consequently, these characteristics make them good reference fishes for scientific research, especially when conducting nutritional studies and determining egg and larval quality (Gordon et al., 2000).
Positive Impacts: pet trade ; ecotourism ; research and education
A. percula interacts with its sea anemone host and other anemonefish species. The symbiotic relationship is well documented to benefit the fish, but equal rewards exist for the anemone. In exchange for protection, A. percula may feed, oxygenate, and remove waste material from its host (Rosenberg and Cruz, 1988). In addition, it may prevent certain coelenterate feeders, such as butterfly fishes, from preying on the anemone (Allen, 1997). Because anemonefishes are highly territorial, A. percula drives away intruders, including those that harm its symbiotic host. Whether these actions are self-serving or altruistic is not known, but both species gain advantage.
Mutualist Species:
A. percula feeds mainly on zooplankton, such as copepods and larval tunicates. Possibly, it consumes algae from the surrounding coral reef or even leftover food portions from its host anemone. The former strategy is commonly used by A. perideraion (Fautin and Allen, 1992). Frequently, A. percula will carry large pieces of food to its host anemone, presumably to store it for later use. The anemone, however, devours the accessible food item in most cases (Grant, 1999).
Optimal juvenile growth rate was discovered at a ration of approximately 6% body weight per day (Johnston et al., 2000). Juveniles are under considerable pressure from the hierarchical structure. The individual is harassed and chased by bigger males of the “family group,” which results in stunted growth. Consequently, the smaller fish has a more restricted feeding area, and more energy must be placed on evasion. Only when a larger male is removed (e.g. death) will the smaller juvenile experience an acceleration in growth rate. It is believed that less time being harassed translates into more time spent on feeding (Fautin and Allen, 1992).
Due to the increased aquarium trade for A. percula (See Economic Importance for Humans) and a continued depletion of coral reef habitats, there have been tremendous developments in rearing of marine fishes using aquaculturing techniques. One of the most challenging obstacles is providing an economical, yet effective, feed in an artificial environment. Hoff (1996) found that A. percula larvae and juveniles could be successfully reared on highly integrated and diverse feeds, such as rotifers, small particulate dry feed, Artemia, and krill meal. Unfortunately, this proved too expensive to be practical, and a regime solely based on artificial feed decreased survival and growth rates in young fishes. If, however, juveniles were weaned from live Artemia 15 to 20 days after hatching and fed a fish meal/casein-based substitute, survival and growth rates showed no difference from juveniles fed entirely on live feed (Gordon et al., 2000).
Animal Foods: aquatic crustaceans; other marine invertebrates; zooplankton
Plant Foods: algae
Foraging Behavior: stores or caches food
Primary Diet: planktivore
True clown anemonefishes (Amphiprion percula) are native only to the Indo-Pacific Region (Rosenberg and Cruz, 1988). The species ranges from Northern Queensland to Melanesia, which comprises New Guinea, New Britain, New Ireland, the Solomon Islands, and Vanuatu (Fautin and Allen, 1992).
Biogeographic Regions: oriental (Native ); australian (Native )
Like all anemonefishes, A. percula forms symbiotic relationships with sea anemones. It uses its host as both shelter and protection from predators. Because of this close relationship, the distribution of suitable host anemone species dictates the habitat of A. percula. Associations involving A. percula and the sea anemone species Heteractis magnifica, Stichodactyla gigantean, and Stichodactyla mertensii are usually found in nature (Elliott and Mariscal, 1996). Both symbionts reside in shallow coastal waters of the tropics where depth rarely exceeds 12 meters and water temperature ranges from 25-28 degrees C. (Randall et al., 1997; Fautin and Allen, 1992). The distribution of sea anemones themselves is limited by the photosynthetic activity of golden-brown algae that occupy the anemones’ tentacles (Fautin and Allen, 1992). The fish and anemone pair generally occurs on coral reefs where the latter is anchored securely and the former can be seen swimming in and out of the protective tentacles of its host.
When several species of anemonefishes occur together in similar habitats, they tend to partition themselves according to microhabitats and available species of sea anemones. A. percula, for example will typically occupy H. magnifica in nearshore zones while Amphiprion perideraion will occupy the same species in offshore zones. Intense competition for limited resources undoubtedly affects the territorial nature of these fishes. Niche differentiation is caused by distribution, abundance, and recruitment patterns of competing species (Elliott and Mariscal, 2001).
Range depth: 1 to 12 m.
Habitat Regions: tropical ; saltwater or marine
Aquatic Biomes: reef ; coastal
Mating System: monogamous
Monogamous pair-bond formations between male and female individuals of A. percula are very strong and correlated with the small territory size that this species occupies. Despite being restricted to the immediate vicinity of its host anemone, A. percula can breed/spawn year round due to the perpetually warm tropical waters they inhabit.
Initiation of courtship is highly correlated with the lunar cycle. The moonlight serves to maintain a high level of alertness in the male, which then leads to increased social interaction with the female. Several days before spawning, the male will show morphological and behavioral changes: fin erection, chasing, nest preparation, and “signal jumping.” This last trait is depicted with rapid up and down swimming motions. Finally, extensions of anal, dorsal, and pelvic fins accompany the aggressiveness of the male (Fautin and Allen, 1992)
The choice of nest site is important for later survival of the eggs. It is usually located under the tentacles of the host anemone and securely positioned on a patch of cleared rock (Myers, 1999). The male has been known to nip at the bottom edges of the tentacles in order to cause retraction, and thus providing enough clearance to clean the area (Rosenberg and Cruz, 1988). Initially, the male clears algae and debris with its mouth only later to be joined by its mate (Fautin and Allen, 1992). There is clear emphasis, then, on male parental care, and this will be crucial when the eggs become vulnerable to predation.
Actual spawning procession takes place during the morning hours, and generally lasts about 30 minutes to more than two hours. At this stage, the conical ovipositor of the female becomes visible. Several eggs are extruded through this structure with each slow and deliberate pass as the belly gently brushes the nest surface. Following closely behind is her mate, who externally fertilizes the eggs as they are laid. The number of total passes during each spawning session is high, and the amount of deposited eggs range from 100 to over 1000, depending on fish size and previous experience. Older, more experienced mating pairs will produce more eggs. The eggs of A. percula are about 3-4 mm in length (Fautin and Allen, 1992).
After egg deposition has finished, the incubation period begins. At this time, the male actively mouths and fans the eggs, while simultaneously being on guard against any predators (Rosenberg and Cruz, 1988). Because the eggs are attached to the bottom substrate via adhesive strands, additional protection is provide by the overhanging tentacles of the host anemone (Allen, 1997). Removal of dead eggs and debris is also important in keeping a well-oxygenated nest and is accomplished by the male. The female, in contrast, is occupied with feeding during this time (Fautin and Allen, 1992).
Breeding season: year round
Range number of offspring: 100 to 1000.
Average gestation period: 6-7 days.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sequential hermaphrodite (Protandrous ); sexual ; fertilization (External ); oviparous
Parental Investment: no parental involvement; pre-hatching/birth (Protecting: Male)
The clownfish(also known as the anemonefish) is a smallspeciesoffishthat is found around tropicalcoral reefs. The most commonly knownspeciesof clownfishis orange with white markings but clownfishcan be found in many differentcoloursand can also differ in shape.
There are 28 recognisedspeciesof clownfishthat are found in the Indian andPacific Oceans. The clownfishis also found as far north as the Red Sea and inhabits the Great Barrier Reef, on the Australian east coast.
The clownfishwas made most famous from the popular children's filmFinding Nemo. Aquatic stores and clownfishbreeders reported a significant increase in the popularity of the clownfishalthough many people did not realise the work that goes into keeping marinefishso sadly, the majority of clownfishbought at the time quickly died.
The clownfishis also famous for it's seeming immunity to the stings of the sea anemone. Most clownfishare found either in or around sea anemones which the clownfishinhabits both for protection frompredatorsbut also the readiness of food.
Clownfishinhabit a single sea anemone ingroupsthat include the breeding male and female and a number of younger male clownfish. All clownfishare born male and develop female reproductiveorganswhen needed. When the female in the sea anemonegroupdies, the dominant male becomes female and breeds with one the males that is inhabiting the same sea anemone.
Female clownfishlay their eggs on a flat surface close to the sea anemone which they inhabit. The female clownfishcan lay hundreds or thousands of eggs at one time depending on thespecies. Clownfishlay their eggs around the same time as a full moon and the male clownfishguards the eggs until they hatch just over a week later.
Clownfishare omnivorousanimalsmeaning that they eat both plants andanimals. Clownfisheat a wide range of food such as algae,plankton,molluscsand small crustaceans. Thedietof the clownfishis however largely dependent on thespeciesof clownfishand what food is available in the area which they inhabit.
Due to their smallsize, clownfishare preyed upon by a number ofpredatorsbut can be difficult to catch are they often retreat into the safety of the sea anemone. Largespeciesoffish, sharks and eels are the mainpredatorsof the clownfishin the water but thehumanis the biggest overall threat to the clownfishas they are caught to keep in tanks and aquariums.
Despite the rising levels of pollution in the world'soceansand destruction of thehabitatson theoceanfloor, clownfishare not considered to be a threatenedspeciesofanimalmainly because they lay so many eggs at a time. Even though not all of the clownfisheggs will hatch, a vast number of clownfishfry hatch in every spawn meaning that clownfishnumbers remain high in the wild.
The Field Museum's What the Fish? podcast
Fish of the Week:Orange Clownfish
http://fieldmuseum.org/explore/multimedia/what-fish-episode-4-sneaker-males-are-my-anemone
The orange clownfish (Amphiprion percula) also known as percula clownfish and clown anemonefish, is widely known as a popular aquarium fish. Like other clownfishes (also known as anemonefishes), it often lives in association with sea anemones. A. percula is associated specifically with Heteractis magnifica and Stichodactyla gigantea, and as larvae use chemical cues released from the anemones to identify and locate the appropriate host species to use them for shelter and protection.[2] This causes preferential selection when finding their anemone host species.[3] Although popular, maintaining this species in captivity is rather complex. The Great Barrier Reef Marine Park Authority regulates the number of collection permits issued to aquarium fish dealers who seek this, and other tropical fish within the Great Barrier Reef Marine Park. The symbiosis between anemonefish and anemones depends on the presence of the fish drawing other fish to the anemone, where they are stung by its venomous tentacles. The anemone helps the fish by giving it protection from predators, which include brittle stars, wrasses, and other damselfish, and the fish helps the anemone by feeding it, increasing oxygenation, and removing waste material from the host. Various hypotheses exist about the fish's ability to live within the anemone without being harmed. One study carried out at Marineland of the Pacific by Dr. Demorest Davenport and Dr. Kenneth Noris in 1958 revealed that the mucus secreted by the anemone fish prevented the anemone from discharging its lethal stinging nematocysts. A second hypothesis is that A. percula has acquired immunity towards the sea anemone's toxins, and a combination of the two has been shown to be the case.[4] The fish feed on algae, zooplankton, worms, and small crustaceans.
Amphiprion percula can grow to be 11 cm (4.3 in) in length, but is on average 8 cm (3.1 in), and can be recognized by three white lines across their bright orange bodies, with no distinction in color between sexes. The anterior white bar is placed just behind the eye, the middle bar goes straight down the middle of the fish, and the posterior bar occurs near the caudal fin. An anterior projecting bulge also exists on the middle bar. In addition to the white coloring, black edging outlines each fin with varying thickness.[3] This species can be mistaken for the similar species of clownfishes, A. ocellaris. This is known as the ocellaris clownfish and sometimes referred to as the "false percula clownfish" or "common clownfish" due to its similar color and pattern. The "easiest" way to distinguish the two species is the fact that A. percula has 10 spines in the first dorsal fin (rarely having 9) and A. ocellaris has 11 (rarely 10), which is a more reliable distinction than color patterns. A. ocellaris does not have thick black edging outlining the fins.[3]
Since these fish live in a warm-water environment, they can reproduce all year long. Each group of fish consists of a breeding pair and none to four nonbreeders. Within each group there is a size-based hierarchy: the female is largest, the breeding male is second largest, and the male non-breeders get progressively smaller as the hierarchy descends.[5] They exhibit protandry, meaning each fish is born male, but changes to female if the sole breeding female dies. If the female dies, the breeding male becomes the breeding female, and the largest nonbreeder becomes the breeding male. The spawning process is correlated with the lunar cycle. At night time the moon maintains a higher level of alertness in A. percula and this increases the interaction with the males and females. Before spawning, the male attracts the female via courting behaviour. These courting actions include extending their fins, biting the female and chasing her. The males also swim rapidly in an upward and downward motion to attract the females. The nest site is also important for the survival of the eggs.[3] Depending on her size, the female spawns about 400–1500 eggs per cycle.[6] The expected tenure of breeding females is roughly 12 years and is relatively long for a fish of its size, but is characteristic of other reef fish.[7]
Why the nonbreeders continue to associate with these groups has been unclear. Unlike nonreproductives in some animal groups, they cannot obtain occasional breeding opportunities, because their gonads are not functional. They cannot be regarded as helpers at the nest, since their presence does not increase the reproductive success of the breeders. Recent research [8] suggests that they are simply queuing for the territory occupied by the breeders, i.e. the anemone; nonbreeders living in association with breeders have a better chance of eventually securing a territory than a nonresident.[5] The probability of a fish ascending in rank in this queue is equal to that of the individual outliving at least one of its dominants because an individual ascends in rank if any one of its dominants dies, and not simply when its immediate dominant dies.[5]
The development of the fish from juvenile to adult is dependent on the system of hierarchy, and can be described as density-dependent. Aggression is involved in these small families, although usually not between the male and the female. The aggression usually exists between the males. The largest male suppresses the development of the next smallest male, and the cycle continues until the smallest fish is evicted from the host anemone. Within each anemone, the regulation of the species is controlled by the female, since the amount of space for fish in her anemone is directly proportional to her size (which eventually reaches a maximum), so she ultimately controls the size of the other fish.[9] A. percula is a very competitive fish and this causes the smaller fish to have stunted growth. A potential exists for a fish to ascend in rank by contesting its dominant. This depends on the relative body sizes of the two fish, and is very unlikely to happen since A. percula maintains well-defined size differences between individuals adjacent in rank.[5] However, in an aquarium, this fish is peaceful, and it can live in an aquarium environment well.
The fish lay their eggs in a safe spot close to the anemone from where they are easily protected, and the parents can retreat to safety if danger threatens. Anemonefish usually lay their nests in the evening after a few days of carefully cleaning and examining the chosen site. Preferred egg sites are flat or slightly curved rocks or some other item the fish have dragged near their nest for the purpose. (In captivity, clay pots and saucers are an attractive choice.) First, the female deposits some eggs with her ovipositor (a whitish tube descending from her belly), making a wiggling pass over the surface, then the male follows behind her, fertilizing the eggs. After many passes, the nest is complete and will hatch in 6–8 days shortly after sunset, usually on a very dark night. In the meantime, the male is very protective of the nest and ceaselessly fans the eggs to provide proper oxygen circulation, and checks them for any bad eggs, which he eats before they can rot and damage more eggs. Females may help the male tend the nest. At hatching, the larvae burst free and swim up toward the moonlight and the open ocean to ride the currents and eat plankton for about a week, before the still tiny metamorphosed clowns return to the reef and look for an anemone in which to settle. Eventually, the cycle repeats.
Recruitment is the number of individuals in a given species that can survive within a certain amount of time following larval habitation.[10] The higher the level of recruitment, the better chance a larva has of surviving long enough to become an adult fish. Large food supplies, low predator threats, and the availability of nearby anemones are all factors that affect their recruitment levels. A. percula, like most coral reef fish, has a bipartite lifecycle, which has a scattering pelagic larval stage, whereas its resident phase is motionless. At the end of the pelagic phase, the larvae begin to settle on the coral reef and begin their recruiting process in the resident population.[5] Larvae that settle successfully and join a resident population are called recruits. Anemonefish species are recruited to areas where the fish are commonly found. Most anemonefish are site-attached and do not move from one anemone to another that are spatially distributed more than a few meters. This is simply because it is always a dangerous undertaking for A. percula to be outside its anemonefish safe haven, exposed to dangerous predators. They are also very poor swimmers, increasing the risk involved in travel.[5] Recruitment is essentially the only method that the fish can use to inhabit new anemones. Finding a better living situation in a different anemone is unlikely because every anemone is already occupied by other anemonefish species. Anemonefish are known for reproducing all year round when they are in lower latitudes and recruitment with these fish is anticipated to follow the same pattern.[10]
Anemonefish are specialized coral reef fish that live within host anemones and are found in warmer waters in the Pacific and Indian Oceans, off northwest Australia, southeast Asia, and Japan.
Both A. percula and the anemones reside in shallow waters and the depth usually does not exceed 12 m with water temperatures ranging between 25 and 28 °C.[3] Host anemones, which are tube-like organisms that reside on coral reefs, are usually occupied by only one anemonefish species because one species outcompetes and exclude other species when they inhabit the same host anemone. Unless a significant size difference exists, two anemonefish species show aggression towards each other when trying to occupy the same host anemone.[10] This is why the supply of nearby anemone hosts so strongly influences A. percula’s ability to achieve recruitment and survival in general.
A primary host anemone has an anemonefish at a high frequency and a secondary host anemone has one at a relatively low frequency. The distribution and availability of sea anemones is limited by the activity of photosynthesis of algae that occupy the anemones’ tentacles.[3] Secondary hosts are usually only used if a severe lack of available primary hosts exists. When many different species of anemonefishes occupy similar habitats, they tend to spread themselves out according to smaller microhabitats and available species of anemones. A. percula and A. perideraion both essentially live within the H. magnifica anemone, but A. percula has the highest selection ratios with the S. gigantea.[10] A study done by Elliot & Mariscal in the region of Madang, Papua New Guinea found that all of the H. magnifica anemones that were censused were occupied by A. percula and A. perideraion. A. percula generally occupies anemones that are near shore, while A. perideraion occupies anemones that are more offshore. Anemonefish do not occupy anemones if they are in shallow water or if they are too small. Shallow waters are not an inhabitable environment for A. percula because of the lower salinity levels, increased temperatures, and exposure during low tides. Also, small anemones would not provide protection from predators.[10] A. percula and the host anemone are very important to one another and interact in a symbiotic relationship. A. percula cleans the host anemone by consuming algae residue and zooplankton such as copepods and larval tunicates. They also protect the anemone from polyp-consuming fish and other predators, while the clownfish is protected from predators by the anemone. A. percula sometimes carries pieces of food to the host anemone for later consumption. In most cases the host anemone then devours the food that A. percula stored around it.[3] Chances of survival for both parties involved are increased through this co-existence.
The larvae of orange clownfish use olfaction to avoid predators, and increased ocean acidification may cause larvae to be unable to differentiate predators from other odors.[11] This could allow them to be preyed upon more easily, and lead to higher population mortality rates. Impairment of larval olfaction may also make them less able to locate appropriate reef habitats at the higher levels of ocean acidification that are projected to occur with increased carbon dioxide emissions.[12] A paper published in Nature in 2020 cast doubt on the effect of acidification, stating "our findings indicate that the reported effects of ocean acidification on the behaviour of coral reef fishes are not reproducible, suggesting that behavioural perturbations will not be a major consequence for coral reef fishes in high CO2 oceans".[13][14] A meta-analysis published in 2022 also found that effect sizes of studies assessing ocean acidification effects on fish behaviour have declined dramatically over a decade of research on this topic, with effects appearing negligible since 2015, representing one of the most extreme examples of the decline effect in ecology.[15]
The development of A. percula is relatively fast. After the eggs are fertilized, they are ready to hatch after about 6–7 days. After hatching, the larvae are very small and are transparent except for the eyes, yolk sac, and a few colors across the body. The larvae then sink to the benthic environment, but then swim to the upper water column. The larvae spend about a week floating among plankton and are transported by ocean currents.[3] The larval stage ends when A. percula settles to the bottom of the ocean. The process from larval stage to juvenile takes about one day. Rapid development of color occurs during A. percula's juvenile stage. During the juvenile stage the anemonefish has to find a suitable anemone host. Specific chemical components are used when finding their host. These chemical cues are different for each anemonefish. This causes preferential selection when finding their anemone host species.[3] When A. percula comes in contact with the anemone, it produces a protective mucous coat. This mucous coat is developed with multiple interactions with the host anemone. A. percula dances around the anemone, touching its fins first to the tentacles and then its entire body during its first interaction with the anemone. This process could take a few minutes or up to several hours.[3] If A. percula does not continue to come in contact with the host anemone, the protective mucus may disappear. A. percula belongs to a group of fishes that are not stung by the nematocysts of the anemone. If A. percula did not have the protective mucous covering, it would be stung. Other fish species that lack the mucous covering are consumed by the anemone.[3]
{{cite journal}}: CS1 maint: multiple names: authors list (link) The orange clownfish (Amphiprion percula) also known as percula clownfish and clown anemonefish, is widely known as a popular aquarium fish. Like other clownfishes (also known as anemonefishes), it often lives in association with sea anemones. A. percula is associated specifically with Heteractis magnifica and Stichodactyla gigantea, and as larvae use chemical cues released from the anemones to identify and locate the appropriate host species to use them for shelter and protection. This causes preferential selection when finding their anemone host species. Although popular, maintaining this species in captivity is rather complex. The Great Barrier Reef Marine Park Authority regulates the number of collection permits issued to aquarium fish dealers who seek this, and other tropical fish within the Great Barrier Reef Marine Park. The symbiosis between anemonefish and anemones depends on the presence of the fish drawing other fish to the anemone, where they are stung by its venomous tentacles. The anemone helps the fish by giving it protection from predators, which include brittle stars, wrasses, and other damselfish, and the fish helps the anemone by feeding it, increasing oxygenation, and removing waste material from the host. Various hypotheses exist about the fish's ability to live within the anemone without being harmed. One study carried out at Marineland of the Pacific by Dr. Demorest Davenport and Dr. Kenneth Noris in 1958 revealed that the mucus secreted by the anemone fish prevented the anemone from discharging its lethal stinging nematocysts. A second hypothesis is that A. percula has acquired immunity towards the sea anemone's toxins, and a combination of the two has been shown to be the case. The fish feed on algae, zooplankton, worms, and small crustaceans.
