The Clark’s Clownfish is a showy anemonefish that is hardy and easily kept in the home aquarium!

The Clarkii Clownfish Amphiprion clarkii is a boldly patterned, durable fish that makes a great addition to just about any saltwater aquarium. It has a stout rounded body and reaches about 5 1/2 inches (15 cm) in length. Different specimens can be quite variable in color withadults ranging from yellow to brown. There aretwo broad whitebands on the body and sometimes a third at the base of the tail. The bright nose and tail fin can range from yellow to white.

Some other common names for this fish include the Clark’s Anemonefish and Clark’s Clownfish along with a bunch of descriptive names like Yellowtail Clownfish, Chocolate Clownfish, Brown Anemonefish, Black Clownfish, and more. There are also some very striking varieties that have been developed, sporting dynamic white blotchs on the sides of the body. Names coined for these include the Picasso Clarki Clownfish, Spotted Clarki Clownfish, and for the newest type, the Galaxy Clarki Clownfish.

Similar types of clownfish species are clustered together in what are known as “complexes”. This fish is the namesake for a group of anemonefish in the “Clarkii Complex”. yet this specieshas some interesting distinctions. This one of the deepest dwelling anemonefish, recorded at depths of 179 feet. Itstail fin is not rounded as that of other clownfish, which gives it the ability to swim faster than the other species. It also has some anomalies in the breeding arena.All clownfish are undifferentiated when born but they are sex switchers. With certain social cues they change into juvenile males, and then one turns into a dominant female for breeding. Quirks for this species include having two clowns that may both turn female, or may both stay male. Also a group of three juveniles raised together may actually breed in a threesome of one overworked male with 2 females, rather than a normal pairing.

The Clark’s Clown are perhaps one of the most durable and enjoyable of the clownfish species. Through successful captive breeding these fish can sometimes be purchased in a pair, but just buying two young fish will usually result in a male and female pair eventually. The normal varieties are readily available and reasonably priced, making them a great choice for the beginner or any marine aquarium enthusiast. The “designer” clownfish are also easily found, but do tend to be expensive.

These anemonefish are very robust. Beingbold strong swimmers, theywill spend most of their time out in the open. They are very easy to keep but will enjoy a little bit more room than most clowns due to their natural ability to swim further. They are less dependent on a host anemone for protection than their cousins. When frightened in the wild, they will often choose to hide within the reef instead of nestling in protective host. Anemonefish are sometimes called “singing†fish as they will make chirping or popping noises, with each different species having its own dialect. This clown has been known to make louder and more frequent noises than other anemonefish, and its “songs” can even be heard outside the tank!

This fish will do well in a either a coral-rich tank or in a fish only tank. Though in the wild they are associated with anemones they will readily adapt without one. Provide it with some rock structures in a fish only aquarium, or an anemone host or other invertebrates in a reef tank. A tank size of at least 30 gallons (114 l) should be provided, much larger if attempting to keep an anemone. These are one the least picky of the anemonefish when it comes to choosing a host. There are a large number of host anemones they will accept in the aquarium, and many of these are generally available. Yet they will often accept other invertebrates as a substitute host. They mayassociate withsome of the soft corals,Euphillia species, mushrooms (corallimorphs), or even algae. They may even adopt a rock structure as a substitute host, or sometimes even a powerhead!

These are community fish and get along with pretty much any fish that will not swallow them whole. In the wild, they are known to share very large anemones with the gentle Pink Skunk ClownfishA. perideraion, but in captivity adults will become very aggressive. Once settled a pair will vigorously defend an establish territory. They are too aggressive to house with other clownfish or more than just a male/female pair. A pair will readily spawn and tenaciously protect their eggs, even in the midst of harassment from other pesky damselfish. They will also defend their host anemone or coral fiercely if laying eggs.

For more Information on keeping saltwater fish see:
Marine Aquarium Basics: Guide to a Healthy Saltwater Aquarium

Clarks Clownfish

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Clark’s Clownfish or Banded Clownfish (Amphiprion clarkii) laying eggs

A very happy Clark’s Clownfish couple is spawning under a rock near their anemone. The anemone is to the left and the eggs are the reddish orange dots. After the male fertilizes the eggs, they fan the new arrivals. Clark’s or Banded Clownfish are readily available, love Bubble Tip Anemones, and are durable fish for the beginner aquarist.

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Actinopterygii
  • Order: Perciformes
  • Family: Pomacentridae
  • Genus: Amphiprion
  • Species: clarkii
Banded Clownfish – Quick Aquarium Care
  • Aquarist Experience Level: Beginner
  • Aquarium Hardiness: Very Hardy
  • Minimum Tank Size: 30 gal (114 L)
  • Size of fish – inches: 5.5 inches (14.00 cm)
  • Temperament: Semi-aggressive
  • Temperature: 74.0 to 82.0° F (23.3 to 27.8&deg C)
  • Range ph: 7.8-8.4
  • Diet Type: Omnivore
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Habitat: Distribution / Background

The Clarkii Clownfish Amphiprion clarkii was described by Bennett in 1830. They have a large distribution in the Indo – West Pacific Ocean, from the Persian Gulf to Western Australia, then the Western Pacific throughout the islands of Micronesia and Melanesia, and north to Taiwan, Southern Japan and Ryukyu Islands. They not been evaluated by IUCN Red List at this time.

They are known by a number of common names which basically describe their coloring or species identification. These include Clark’s Anemonefish, Yellowtail Clownfish, Clark’s Clownfish, Clark’s Clown, Black Clown, Brown Anemonefish, Chocolate Clownfish, Two Banded Anemonefish, Sebae Anemonefish, and Sea bee.

This fish is the namesake for the group of anemonefish in the “Clarkii Complex”. They are one of 11 clownfish in the Clarkii group. These anemonefish are typically less reliant on their host anemone for protection. They are also the best swimmers of all clownfish complexes. Some others familiar species in the Clarkii Complex are the Allard’s ClownfishA. allardi, Oman AnemonefishA. omanensis, Twobar Anemonefish A. bicinctus, and Three-band ClownfishA. tricinctus.

They have been bred in captivity. There are now variations in color morphs that have earned the names “Picasso Clark’s Clownfishâ€, “Spotted Clark’s Clownfishâ€, and the newest type, the “Galaxy Clarki Clownfish”. These are priced according to how unique their patterning is. A hybrid between this species and its close relative, the Three-band Clownfish Amphiprion tricinctus has also been aquacultured by Oceans, Reefs & Aquariums (ORA).

In nature the Clarkii Clownfish are usually found at depths between 3 – 197 feet (1 – 60 m), which is deeper than most anemonefish dwell. They inhabit outer reefs, living on reef faces and reef slopes, and they inhabit lagoons. They are found in areas of coastal, coral, and rocky reefs around islands.

They can be found as adult pairs with some sub adults and juveniles, as single female adults with multiple non-breeders, as groups of one or two sub adults or as a group of just juveniles. There have been groups of up to 10 individuals consisting of an adult pair with non-breeders and juveniles in one social unit. This species is an opportunistic eater feeding on zoo plankton, benthic algae and weeds, small shrimp, amphipods, polychaete worms, etc.

The Clark’s Clownfish has been known to associate with 10 different sea anemones, including Cryptodendrum adhaesivum, Entacmaea quadricolor, Heteractis aurora, Heteractis crispa, Heteractis magnifica, Heteractis malu, Macrodactyla doreensis, Stichodactyla gigantea, Stichodactyla haddoni, and Stichodactyla mertensii.

They have also been observed within certain species of large polyped stony corals (LPS), soft corals, mushroom corals (corallimorphs). and at times temporarily hiding within Acropora species of small polyped stony corals (SPS). It is interesting to note that the Clark’s Clownfish is naturally protected from the stings of several different corals and anemones. They also don’t seem to have as intensive an acclimation process with these hosts that most clownfish do.

The Clark’s Clownfish are often confused with the Sebae Clownfish (Sebae Anemonefish) Amphiprion sebae. However the Clark’s is readily distinguished by the striping since the Sebae’s second white stripe curves back into the second dorsal fin. The Sebae also has an elongated, narrower body, and the Clarkii Clownfish are deeper bodied fish in comparison. The Three-band Clownfish Amphiprion tricinctus also has a similar appearance except it has a third distinctive band at the base of the tail fin, and its tail fin is dark brown to black, while the tail fin of Clarkii Clownfish is always white to yellow.

  • Scientific Name: Amphiprion clarkii
  • Social Grouping: Varies – Pairs or adult female led groups, both groupings are usually accompanied with non-breeders.
  • IUCN Red List: NE – Not Evaluated or not listed


The Clark’s Clown is a deep bodied clownfish from the Clarkii Complex. These fish typically have stout, rounded body and a forked tail, which helps them to swim faster than other anemonefish that have rounded tails. They can reach up to 5.5 inches (14 cm) in length. This species is known to live up to 14 years in the aquarium, and are recorded at 13 year in the wild. A 2012 study conducted under the Alabama Marine Biology Program suggests the potential lifespan for anemonefish could actually be very long, up to 30 years.

The boldly patterned body can be quite variable in color as an adult. Adults can range from a yellow or brown base color with either two or three wide vertical white to gray bands. The band on the tail can be missing on some adults. One band is located just behind the eye, a second is just in front of the anal fin, and a third is at the base of the tail fin. The band on the tail can be missing on some adults. The face or nose area is usually white. Males tail fins will be yellow or will at least have some yellow on their tail fin, but some females tail fins can change to white as they mature. Juveniles are a cinnamon brown color with a yellow nose and two white body bands.

  • Natural Color Forms
    There are eight different color forms depending on where the clownfish is located. As adults they all retain the same two vertical white bands but the color morphs can have a variation of the tail fin coloration, being white to yellow or a combination. Some of the common colorations include:The aggressive fish has specific actions in which the subordinate clownfish reacts to:
    Clark's Anemonefish, Amphiprion clarkii, Black Variety
    Clarkii Clownfish, Black Variety
    • The Indo-Pacific color morph is a white note, orange face, eyes, gills, pectoral and pelvic fins and a brown to black body and white tail fin. This variation can also have an all yellow tail or a white tail with yellow edges.
    • The Japanese color morph has on almost purple hue to the nose. It is black above the eye, including the head, and yellow to orange from below the eye, including pectoral fins, gills, chin, chest, and belly. The anal fin and tail fin are also yellow, and the rest of the body is black to brown.
    • An all black body with a white nose and white at the base of the tail, with the tail also being white or light yellow.
    • An all black body with a white nose, white at the tail fin base, yellow tail fin, and the pectoral fins having yellow tips.
  • Captive Bred Color Forms
    They have been bred in captivity and there are now variations in the color morphs that have earned a variety of descriptive common names. These are priced according to how unique their patterning is. Some of these include:
    • “Picasso Clark’s Clownfish”
    • “Spotted Clark’s Clownfish”
    • The newest type is the “Galaxy Clarki Clownfish
  • Size of fish – inches: 5.5 inches (14.00 cm)
  • Lifespan: 14 years – Longest recorded lifespan for Clark’s Clownfish is 14 years in captivity. They have been reported to live 13 years in the wild.

Fish Keeping Difficulty

The Clarkii Clownfish are very hardy and easy to care for. They make great fish for the beginning aquarist. These clowns are very easy to maintain, just make sure when purchasing to geta fish that is eating. You can ask the store to feed the tank just to be certain. A specimen should also be alert. Avoid any specimens that have any excess slime or mucus or white casting on their back. Small white spots on their body is also a warning sign of Crypt and these specimens should be avoided.

  • Aquarium Hardiness: Very Hardy
  • Aquarist Experience Level: Beginner

Foods and Feeding

The Clark’s Clownfish are omnivores. In the wild they feed on zoo plankton, benthic algae and weeds, small shrimp, amphipods, polychaete worms, and more. In the aquarium they will eat a wide variety of live, frozen and flake foods. They will also consume naturally growing algae in the tank..

It is important that you feed a variety of fresh or frozen meaty foods for most of their diet. Good foods include fish or shrimp flesh, finely chopped, along with mysis and brine shrimp. Their diet should also consist of a variety of vegetable source foods in pellet and flake form. Feed 3 to 4 times a day as juveniles and twice a day as adults. Provide an area in the tank where the water is not too strong, so they can feed easily.

  • Diet Type: Omnivore
  • Flake Food: Yes
  • Tablet / Pellet: Yes
  • Live foods (fishes, shrimps, worms): Some of Diet – Live foods can be fed as a treat periodically or when conditioning them to breed.
  • Vegetable Food: Some of Diet
  • Meaty Food: Most of Diet
  • Feeding Frequency: Several feedings per day – Feed twice a day as adults and 3 to 4 times as juvenile

Aquarium Care

These clownfish are hardy and fairly easy to keep. They do well when provided good water conditions and a well maintained tank. Guidelines for water changes with different types and sizes of aquariums are:

  • Fish only tanks:
    • Nano/Small tanks up to 40 gallons, perform 15% water changes bi-weekly.
    • Medium sized up to 90 gallons, perform 20% to 30% monthly depending on bioload.
    • Large Tanks 100 gallons and over, once water is aged and stable can be changed 20% to 30% every 6 weeks depending on bioload.
  • Reef tanks:
    • Nano/Small tanks up to 40 gallons, perform 5% water changes weekly.
    • Medium sized up to 90 gallons, perform 15% bi-weekly.
    • Large Tanks 100 gallons and over, once water is aged and stable can be changed 10% bi-weekly to 20% monthly, depending on bioload.

For more information on maintaining a saltwater aquarium see: Saltwater Aquarium Basics: Maintenance. A reef tank will require specialized filtration and lighting equipment. Learn more about reef keeping see: Mini Reef Aquarium Basics.

  • Water Changes: Bi-weekly – Standard maintenance is bi-weekly water changes of 15% every 2 weeks or 30% a month. If there are corals in the tank then 5% weekly to 15% every 2 weeks, depending on the tank size.

Aquarium Setup

The Clarkii Clownfish is a good sized, active clown. It needs a minimum tank size of 30 (114 L) gallons for a single specimen, though 40-50 gallons will suit it better, and 55 gallons minimum for a pair. Keep in mind smaller tank sizes result in water quality degrading quicker, thus requiring 5% water changes every week. Although they are tolerant of less than perfect water quality, prolonged poor water quality will result in illness and disease with any saltwater fish.

Provide with live rock and form some hiding places if there is no anemone present. Swift water movement will make it very hard for them to swim, so if you have a fish in the tank that needs swift water movement, provide that towards the back of the tank so your clownfish won’t get blown away. It is a bold fish that will swim to the surface to eat once it becomes accustomed to its home.

This species lives in tropical areas, so maintain aquarium water temperatures between 72°F to 82°F (22 – 28°C), and they can tolerate a pH range from 7.8 to 8.4. Extremes above 90° F (32° C) or below 64° F (18° C) would be beyond their tolerance. Optimum spawning occurs between 79°F to 83°F (26°C to 28°C).

If you are attempting to keep them with an anemone, the tank size should be appropriate to the particular anemone’s needs. With an anemone it will need to have adequate lighting and the tank should be well established, meaning 6 months to a year old. They will spend the majority of their time with a host but will also swim in all parts of the aquarium, so they need some open space for free swimming.

  • Minimum Tank Size: 30 gal (114 L) – A minimum of 30 gallons is recommended for a fish only tank, though 40-50 gallons is better. A larger tank, 55 gallons or more, will be needed if keeping it with an anemone.
  • Suitable for Nano Tank: No
  • Live Rock Requirement: Typical Plus Hiding Places – Rock structures are important when there is no host anemone or coral present.
  • Substrate Type: Any
  • Lighting Needs: Any
  • Temperature: 74.0 to 82.0° F (23.3 to 27.8&deg C)
  • Breeding Temperature: 79.0° F – The best quality eggs and larvae occur with temperatures of 79° F to 83° F (26° – 28°C).
  • Specific gravity: 1.023-1.025 SG
  • Range ph: 7.8-8.4
  • Brackish: No
  • Water Movement: Any – Provide areas of the tank with calmer waters for feeding.
  • Water Region: All – When kept with an anemone they will spend the majority of their time with their host, but will also swim in all parts of the aquarium.

Social Behaviors

The Clarkii Clownfish are semi-aggressive and is one of the more aggressive clownfish. They can be kept in a reef setting or a fish only setting. but like all damselfish they can be territorial and aggressive, especially as they get older. Though they get along with most tank mates, peaceful fish may be picked on. Once an adult pair has bonded, any other clown fish pairs will be attacked. Some docile damselfish could also be harassed by this clown.If keeping them with an anemone, your choice of tank mates opens up a little more to include larger semi-aggressive fish, due to the protection by the anemone. With large angelfish, triggers, perches or other territorial fish, add the clownfish first. Dottybacks should never be in the same tank with them and predatory fish that are large enough to swallow the clownfish whole should be avoided.

  • Compatibility with other Clownfish:
    Due to their aggression towards other clownfish species, the Clark’s Clown shouldn’t be housed with other types of clownfish. While being attacked or in attacking mode, clownfish produced from 2 to 17 clicks in a row. They will at times produce “chirps” (aimed at larger fish) and “pops” (aimed at smaller fish) that are audible to divers or even aquarists. They are actually silent when mating. Pops are heard in sets of two or one, right before a chirp noise, so they may be carrying on two different conversations! Saying, “Get out of here Angelfish!” and “hey you subordinate, get in line!”

    They use their teeth to produce the sound and the jaws are the built in amplifier, so it stands to reason that the noises may very from clownfish species to species, sort of like a dialect or accent. There are a total of 29 clownfish that produce audible sounds, with some louder than others. Within the loudest three are the Clark’s Clownfish, Tomato Clownfish, and Pink Skunk Clownfish.

    The behaviors between the same species of clownfish are very interesting and easy to identify. Constant dominating displays by a female prevents a male from changing sex. An aggressive clownfish will displays “agonistic behavior” while the subordinate clown will display “appeaser behavior.†The aggressive fish has specific actions in which the subordinate clownfish reacts to:
    • If the aggressive fish, typically the female, is chasing and chirping, the subordinate clownfish, which can be a male or sub adult, will rapidly quiver their body as they drift upward and they will produce clicking sounds.
    • Jaw popping by the aggressive clownfish results in the subordinate clownfish shaking their body or head.
    • Ventral leaning by the aggressive clownfish results in the subordinate clownfish quivering.
    • An aggressive clownfish displaying a dorsal leaning results in the subordinate clownfish performing ventral leaning.
  • Compatibility in a mini reef:
    In a reef setting, clownfish fit in perfectly, especially with a host anemone. Clownfish will typically not bother any corals, with the exception of picking algae off the base of a coral that they have adopted as a host. A host anemone will provide a rich naturalistic environment for your clown. While other fish avoid the anemones stinging tentacles least they become its food, your clown fish will spend most of its time nestled down in it. Though sea anemones are a striking addition to any reef aquarium, they are more challenging to keep. If you decide to keep an anemone you must make sure its special needs are met.

    Even without an anemone, the Clark’s Clownfish will still thrive. These clownfish have been known to adopt alternate hosts.It may choose soft corals or large polyped stony corals (LPS) of the Euphillia family as surrogate hosts. Hairy mushroom corals are also a favorite surrogate host. With any non anemone host. Hairy mushroom corals are also a favorite surrogate host. With any non anemone host, make sure the Clark’s Clownfish is not irritating any of these corals to the point where they are not opening or they will eventually starving to death.

    Be cautious with the Elephant Ear Mushroom or Giant Cup Mushroom Amplexidiscus fenestrafer. It has been known to trap and eat juvenile clownfish and should be monitored. Large adults may not be at risk. As far as inverts are concerned, most are not going to be threatened by a Clark’s Clownfish, unless it is a non-cleaning shrimp such as a Pistol Shrimp, Marbled Shrimp, Sexy Shrimp, etc. These types of shrimp are sometimes purposely knocked or dragged into the host anemone by the Clark’s Clownfish!
  • Compatible host anemones:
    The relationship a clown fish and a sea anemone have is known as symbiosis, where they provide benefits to one another. Clownfish stay with certain anemones in the wild, protecting them from anemone eating fish. In return the anemone protects the clownfish from predators, keeping them away with their stinging tentacles. Clownfish become immune to the sting of the anemone’s tentacles. Feeding is another benefit, the clownfish gets to snack on the remnants of any meal the anemone has captured. The clownfish will also perform housekeeping duties by removing pieces of detritus picked up from the substrate. It is also thought that the anemone is nourished by the waste of the clownfish.

    This species has been known to associate with 10 different sea anemones. These host anemones include:

Be cautious adding Condy Anemones Condylactis gigantea. These are very mobile, predatory anemones, and are not a “clown hosting anemoneâ€. Their sting is much stronger than clown hosting anemones, and there is a risk to the clownfish who is foolish enough to engage it may eventually be eaten. Many who have had clowns hosted by Condylactis have said, “one day the clownfish was gone, and I kept the anemone well fed!â€.

  • Venomous: No
  • Temperament: Semi-aggressive – They are about an 8 on the clownfish aggression scale of 1 to 10, with 10 being the most aggressive.
  • Compatible with:
    • Same species – conspecifics: Yes – Can be kept as a male/female pair or as two or more sub adults.
    • Peaceful fish (gobies, dartfish, assessors, fairy wrasses): Monitor – May harass smaller peaceful fish that are added after them.
    • Semi-Aggressive (anthias, clownfish, dwarf angels): Safe – Do not house with other clownfish.
    • Monitor – Not advisable in smaller 30 gallon tanks. Damselfish are okay with if the tank is very large, over 100 gallons and there are plenty of places for the damsels or clowns to hide. Do not house with dottybacks.
    • Large Semi-Aggressive (tangs, large angels, large wrasses): Safe – Add the clownfish first, and once acclimated, you can add these other fish.
    • Large Aggressive, Predatory (lionfish, groupers, soapfish): Monitor – As long as the fish is not large enough to swallow your clownfish whole.
    • Threat – Clownfish will out compete these fish for food.
    • Anemones: Safe – This species has been known to associate with 10 different clown hosting anemones. Do not house with Condylactis Anemones as these are not clown hosting anemones and may eventually kill and eat your clownfish.
    • Mushroom Anemones – Corallimorphs: Safe – Large mushrooms such as Elephant Ear Mushrooms (Amplexidiscus fenestrafer) can trap and eat juvenile clownfish.

    • LPS corals: Safe – At times will use certain corals as hosts if anemones are not present. Make sure the coral stays open and feeds
    • SPS corals: Safe
    • Gorgonians, Sea Fans: Safe
    • Leather Corals: Safe
    • Soft Corals (xenias, tree corals): Safe – At times will use certain corals as hosts if anemones are not present. Make sure the coral stays open and feeds
    • Star Polyps, Organ Pipe Coral: Safe
    • Zoanthids – Button Polyps, Sea Mats: Safe
    • Sponges, Tunicates: Safe
    • Shrimps, Crabs, Snails: Monitor – Clark’s have been known to knock or drag ornamental shrimp such as pistol shrimp and saron shrimp into their host anemone at feeding time!
    • Starfish: Safe
    • Feather Dusters, Bristle Worms, Flatworms: Safe
    • Clams, Scallops, Oysters: Safe
    • Copepods, Amphipods, Mini Brittle Stars: Safe

Sex: Sexual differences

Males and females are very similar in size, but their coloring is typically different. For example, in some localities, male’s tail fins will be yellow or they will at least have some yellow on their tail fin, but some females tail fins can change to white as they mature.

Breeding / Reproduction

The Clarkii Clownfish has been bred in captivity, but this particular species also has some unusual anomalies for clownfish in the breeding arena. Although they will form pairs, similar to other clownfish, they are notable in that they are not “faithful”. Males will mate with other females and females will mate with other males if they are in close proximity. This particular species also has quirks including having a pair of two clowns that may both turn male, or may both stay female. Also a group of three juveniles raised together may actually breed in a threesome; one overworked male with 2 females, rather than a normal pairing.

They will spawn all year in tropical seas between 72° – 88° F (26° – 28° C). It has been shown that the best quality eggs and larvae happens when the temperature is 79° – 83° F (26° – 28° C). In seas where the water is cooler during the winter months, such as southern Japan, spawning takes place from the middle of May to October when the water temperature is 79° F or higher. They spawn 2 to 3 times a month in warmer temperatures.

Three to five days before spawning, courtship begins where the male bites at the substrate in increasing frequency and intensity. It is thought that the female initiates courtship by nudging the side of the male, or by first engaging in biting at the substrate to encourage his behavior. As the male and female pairs get older, less aggression exists between them during courtship.

Clownfish have several different types of displays when courting, such as leaning away from each other so their ventral surfaces are close, or leaning towards each other with their dorsal surfaces close while shaking their heads. Head standing is also another position where one or both fish will engage. The male and female will soon start to meticulously clean an egg laying site as the spawning event nears. This will be done on a rock or coral close to the anemone, which cleans the area of detritus and algae and provides a clean spot for the spawn.

Once the area is prepared, the pair will then nip at the anemone’s tentacles causing it to retract and expose the cleaned area. At this point, the female will then press her belly on the spawning site and begin to quiver as she drags her abdomen leaving a trail of eggs behind her. She will continue in a circular motion until she deposits all her eggs. After this the male swims behind her and immediately fertilizes them. Spawning occurs between 9 o’clock in the morning and 3 o’clock in the afternoon and can last up for 2 1/2 hours.

A clutch of Clark’sAnemonefish eggs can number on average from 435 to 981 eggs, (some very large females in Japan are said to lay up to 2,500 per clutch!) depending on age and size of the female and measure from 2.2 to 4.0 mm long and are orange in color. The eggs become darker grays or brown as they mature, and before hatching will develop a silver sheen.

The eggs are fanned and mouthed to keep them oxygenated and free of debris and fungal infections. Males do more of the cleaning and guarding in the wild, and intensive fanning of the eggs occurs the day of hatching. They will hatch in 6 to 13 days depending on water temperature. Hatching occurs at night about 1 to 1 1/2 hours after sunset and all will hatch with in two hours. The larvae then swim into the water column which lasts 7 to 9 days.

After the young Clownfish has left its larval stage and is now free swimming, their first priority is to find an anemone for protection. It has been noted by scientists the possibility of two forms of recognition of an anemone that a young Clownfish uses. The first way they are attracted to a specific species of anemone, is the olfactory or scent that the anemone emits, guiding the young fish to the safety of their tentacles. The second way is visual, or recognition of the anemone. Either way, these cues would have been imprinted on the clownfish while developing inside their eggs, by recognition of their parents swimming within the tentacles and the “odor†that the anemone would give off within the mucus of the oral disc and tentacles.

In captivity, they will spawn 2 to 3 times a month, and their nests average 600-700 eggs. The larval period is 7-9 days and they take about 4 to 5 months to mature enough before they are ready to be sold.

For more about breeding clownfish, see Breeding Clown fish: Part One, Breeding Clown fish: Part Two, and Breeding Clown fish: Part Three.

  • Ease of Breeding: Moderate

Fish Diseases

Typically clownfish are extremely hardy, so disease is not usually a problem in a well maintained aquarium. However when they do get sick some diseases are quite deadly. Clownfish are susceptible to the same types of illnesses as other marine fish including bacterial, fungal, parasitic or other diseases, and injury. All saltwater fish will get sick if good water quality is not maintained, the temperature fluctuates too much, or the fish is stressed due to inappropriate tank mates. A stressed fish is more likely to acquire disease.

Clownfish are particularly prone to Brooklynellosis or Clownfish Disease Brooklynella hostilis (Brook), Marine Ich Cryptocaryon irritans, also called White Spot Disease or Crypt, Marine Velvet or Velvet Disease Oodinium ocellatum (Syns: Amyloodinium ocellatum, Branchiophilus maris), and Uronema disease Uronema marinum. All of these are parasites.

The most easily cured of these is Crypt (salt water Ich), but they are all treatable if caught in a timely manner. Marine Velvet is a parasitic skin flagellate and one of the most common maladies experienced in the marine aquarium. It is a fast moving that primarily it infects the gills. Brook kills within 30 hours but the Uronema disease is one of the quickest killers, as in overnight. Uronema is often contracted when the aquarist lowers their salinity to treat another type of illness, but don’t lower it far enough. This parasite thrives in mid-level brackish water salinity, which is a specific gravity of around 1.013 to 1.020.

Be sure to treat for any illness at a normal salinity with a specific gravity of about 1.023, or at a low salinity of about 1.009. Quick Cure and other 37% Formalin products will work perfectly well in both salinity ranges, but the lower 1.009 will help with the oxygen level. The amount of oxygen in the water increase as the salinity level is reduced. “I personally noticed when battling Brook or Crypt using the proper hypo-salinity of 1.009, no higher, my clowns almost seemed to breath easier and be less stressed”… Carrie McBirney.

Anything you add to your tank that has not been properly cleaned or quarantined, including live rock, corals and fish can introduce diseases. The best prevention is to take care to properly clean or quarantine anything you want to add to the tank. A few other ways to proactively prevent disease are to provide quality foods, clean good quality water, and proper tank mates. For information about saltwater fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.


The Clarkii Clownfish is regularly available online and in pet stores, and is very moderately priced. The captive bred varieties called by names like Picasso Clark’s Clownfish, Spotted Clark’s Clownfish, and the newest type, the Galaxy Clarki Clownfish, may cost significantly more than a regular Clark’s Clownfish due to their unique markings.