The Maroon Clownfish is a one-of-a-kind, strikingly beautiful but can be “meaner than a junkyard dog”!

It is hard to confuse the Maroon Clownfish Premnas biaculeatus with any of the other clownfish species. It has a wide distribution across the Indo-west Pacific into the Indo-Australian Archipelago, but it is a one-of-a-kind specimen in a genus all its own.

It can be differentiated from all the other clownfish by a uniform red color and spines sticking out from its cheeks. Due to these cheek spines, in 1790 Bloch originally described it as Chaetodon biaculeatusChaetodon are actually butterflyfish and those fish do have these spines, while this fish is a clownfish. But because of its spines it is also known by the common names Spinecheek Anemonefish and Spine-Cheek Clownfish, as well as the Maroon Anemonefish.

The females of this species are some of the largest Clownfish. They can reach up to 6.3 inches (16 cm) in length. Some report they can grow even bigger in captivity, to as much as 8 inches in length! Males on the other hand are much smaller, often only 1/3 the size of a female though they can reach just shy of 6 inches (13 cm) in length.

These clowns are very similar in shape to the True Percula and Ocellaris Clownfish of the Percula Complex. And like other clownfish, they  have several color variations. They can range from brilliant orange, red or maroon, to a purplish brown. They are accented with three vertical bars that can be thin or broad, and some specimens will be “mis-barred”. Mis-barred means the bars are just across the top of the body, and not extending down the sides.

There have long been two distinct geographic variants, one with white bars and one with yellowish or golden bars. The golden striped variety originates from Sumatra and maybe eastern Java.  But a new variant has also been imported as recently as 2012, and it has bars replaced with a netting or “lightning” type patterning. It was collected from New Guinea off of Fisherman’s Island, and it has created an exciting stir in the hobby. These types are now being selectively bred in captivity but are quite pricey. Their newly aqua-cultured babies are referred to as little “sparks”, how cute is that!

Maroon Clowns are bred in captivity. They are available individually as well as in pairs, but Maroons are always a bit more expensive than most of the other clownfish species. Depending on their looks some of the descriptive common names they are known by include Gold Stripe Maroon Clownfish, Yellow stripe Maroon Clownfish, and White Stripe Maroon Clownfish, along with the two “designer” names of Llghtning Maroon Clownfish, and Orange Jaw Purple Maroon Clownfish.

This is a great fish for the beginner because it is very hardy, but it can get fairly large and can be very territorial. “Meaner than a junkyard dog” may be the first thing that comes to mind with this beauty because it is one of the few clowns that can hold its own in an aggressive tank. It makes an interesting “character” in the aquarium but is so aggressive that it’s difficult to keep even with other damsels. Females have been known to rush to the front of the tank and shake their pectoral fins back and forth to warn visitors of their ferocious and fearless nature, sometimes even picking up and spitting rocks or pieces of gravel!

Maroon Clownfish should not be kept with docile fish such as gobies, dartfish, etc., and they will kill other clownfish. Be willing to remove other fish from the tank, since a Maroon Clownfish may decide one day that a particular fish needs to die! Having a spare tank up and running is a great idea until your tank is fully stocked and all your charges are getting along. They are great for an aggressive tank theme. This is one fish that does well with more belligerent fish like triggers and large angelfish, just make sure to add the clownfish first and give it time to settle in.  These clownfish are easy to keep with larger semi-aggressive fish and smaller aggressive fish like line wrasses, as well as most eels. Large Anthias may hold their own with this clown, and dwarf angelfish who are more aggressive may also hold their own in a larger tank. Still, keep an eye on these fish to make sure they are not being attacked.

These guys are as durable as they are mean! Provide at least 30 gallons for one Maroon Clownfish, and 55 gallons for a pair. Like all saltwater fish good water quality helps keep them healthy. They are harder to pair up as a male and female, compared to other clownfish. These females are much more picky about their mates, to the point of killing an unacceptable specimen. Once a mate is accepted, the female will defend it to the end. But the female is the dominant fish and can be moody. A lot of rock work to hide in or a large anemone is needed for the male to retreat into, when the female’s aggressive nature comes out. They tend to stay where they have adopted an anemone, coral, or other substitute host, but may swim at all levels of the aquarium at times. As they are not the most agile swimmers, so water movement should not be swift in the area the clown has adopted.

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

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Actinopterygii
  • Order: Perciformes
  • Family: Pomacentridae
  • Genus: Premnas
  • Species: biaculeatus
Maroon Clownfish – Quick Aquarium Care
  • Aquarist Experience Level: Beginner
  • Aquarium Hardiness: Very Hardy
  • Minimum Tank Size: 30 gal (114 L)
  • Size of fish – inches: 6.3 inches (16.00 cm)
  • Temperament: 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

Maroon Clownfish Premnas biaculeatus was described by Bloch in 1790 from specimens collected in the East Indies (Indonesia today). Due to its having cheek spines, Bloch originally described it as Chaetodon biaculeatus, which is one of the butterflyfish genera. They are found in the Indo-West Pacific and into the Australian Archipelago, including India, Philippines, Burma, Thailand, Malaysia, Indonesia, Northern Queensland, New Guinea, Solomon Islands, Vanuatu, and New Britain. They are not listed on the IUCN Red List for endangered species.

Descriptive common names for this species are derived from the obvious maroon color that they possess, its cheek spines, or its family group. Some of the names this fish is known by include Spinecheek Anemonefish, Spine-Cheek Clownfish, Spine-Cheek Anemonefish, Damselfish, Maroon Anemonefish, Gold Stripe Maroon Clownfish, Gold Stripe Clown, Yellow stripe Maroon Clownfish, White Stripe Maroon Clownfish, and in is even called Tomato Clownfish in Australia.

There are two distinct geographic variants. One has white bars and the other has yellowish or golden bars and comes from Sumatra and maybe eastern Java. A new strain, collected from New Guinea off of Fisherman’s Island, was imported in 2012. The barring of the common species was replaced with a netting or “lightning” type patterning on this fish.

The new strain had its first captive bred brood in spring of 2012. Breeder Matt Pedersen saw approximately 50% lightning patterning in the offspring. The male had the typical maroon coloring overall, but instead of white thin bands, the white pattern look like white netting or lightning. The specimens around Fisherman’s Island just off Papua New Guinea seem to carry this lightning gene even if they have the normal stripes. The female he used was from the same island as the male. The newly aqua-cultured babies were referred to as little “sparks.” Two “designer” names for these fish include Lightning Maroon Clownfish and Orange Jaw Purple Maroon Clownfish.

The Spinecheek Anemonefish are found in seaward reefs, protected coastal waters, and lagoons at depths between 3 to 53 feet (1 – 16 m). As adults they are found in pairs, while juveniles may be found in small groups. They feed on benthic weeds and algae, as well as zooplankton and some small invertebrates.

They have been known to associate most commonly with the clown-hosting Bubble Tip Anemone Entacmaea quadricolor. They have also been seen by divers associating with the Magnificent Sea Anemone Heteractis magnifica and the Sebae Anemone Heteractis crispa. But the Bubble Tip Anemone is their preferred host and they will kick out other clownfish species attempting to inhabit it!

  • Scientific Name: Premnas biaculeatus
  • Social Grouping: Pairs – Adults are found in pairs. juveniles may be in small groups.
  • IUCN Red List: NE – Not Evaluated or not listed


The Maroon Clownfish is the only member of the Maroon Complex. They have spines on their cheek area and their scales are smaller than other clownfish. They have a more compressed oval shape than clownfish from the Clarkii complex, who are more high backed, yet are almost identical in body shape the the Ocellaris Clownfish and True Perucla Clownfish of the Percula Complex, including the double dorsal fin.

The female can grow up to 6.3 inches (16 cm) in length while the male is much smaller. Males may often be about 1/3 the size of the female, and at most they will only reach a little over 5 inches (13 cm). Maroon Anemonefish have been recorded to have a lifespan of 20 years, but a 2012 study conducted under the Alabama Marine Biology Program suggests the potential lifespan for anemonefish could actually be very long, suggesting up to 30 years. A male/female Maroon Clown pair at Oceans, Reefs & Aquariums (ORA) are still spawning at 35 years.

Their coloring, including all of the fins, is uniform overall. It ranges from bright orange or red to a deep brownish purple. Males are usually a brighter red than females. They will have 3 vertical thin white bands or 3 vertical thicker yellow bands. The first stripe is behind the eyes, the second is in between the two dorsal fins, and the third is at the base of the tail fin. There are color variations that include missing bars, bars that don’t extend all the way to the bottom of the fish, as well as some fish bearing much darker versions of the full length stripes. On adult females the bars are typically gray, though they can quickly turn white if the fish is provoked.

A new variety with a white lightning or net patterning was captured from New Guinea off of Fisherman’s Island and imported for the first time in 2012. It is called the Lightning Maroon Clownfish and was successfully bred in the spring of that same year. About half of the brood had this white lightning patterning instead of thin white stripes. It was found that if the male has the pattern (even if the female does not) they will produce some offspring with this very cool net patterning. Two “designer” names for this variant are Lightning Maroon Clownfish and the Orange Jaw Purple Maroon Clownfish, which has a purplish brown hue to it and its lower jaw is a brighter orange.

Of the two most common colorings, the deep red to chocolate colored variety from Sumatra with 3 vertical wide yellow stripes is the most popular. The color variation which is a bright red to orange color has 3 vertical thin white stripes, and it is said to be the more aggressive of the two colors.

  • Size of fish – inches: 6.3 inches (16.00 cm) – Females reach lengths of up to 6.3” (1 cm) but males are much smaller, reaching 5.11” (13 cm) at most. Some have reported having an 8” female, which may be possible in captivity.
  • Lifespan: 20 years – hough they reportedly have a lifespan of 20 years, they may live much in captivity with proper care. Oceans, Reefs & Aquariums (ORA) has a pair that are still spawning after 35 years.

Fish Keeping Difficulty

Maroon Clownfish are hardy and easy to keep as long as water conditions are acceptable. They make a great fish for the beginning aquarist, but they are aggressive which will limit the selection of tank mates. The biggest concern with these fish is if you are keeping a pair. A moody, aggressive female picking on the male will cause a great deal of stress, which will eventually mean a sick fish.

It is recommended when keeping a pair to have a larger tank and provide a large anemone or a lot of rock work with hiding places that the female cannot fit into. For pairing them up, read about social behaviors below. To keep them with an anemone, provide the proper sized tank for that specific anemone, as well as its necessary lighting. A nice thing about keeping an anemone is that due to the protection it affords the clownfish, your choice of tank mates will expand a little more.

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

Foods and Feeding

The Maroon Clownfish are omnivores. In the wild they feed mostly on zooplankton and different types of algae. 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. You can feed them mysis shrimp, brine shrimp, finely chopped fish, and chopped mussels. Their diet should also consist of a variety of vegetable source foods. They will take flake and pellet, but be sure these have spirulina added if there is not enough algae in the tank for them to eat, Feed 3 to 4 times a day as juveniles and 2 to 3 times as adults. Offer a varied diet in smaller amounts, instead of one large feeding. Provide an area in the tank where the water is not too strong, so they can feed easily.

  • Diet Type: Omnivore – Include spirulina foods, especially important if there is a lack of algae in the tank.
  • Flake Food: Yes
  • Tablet / Pellet: Yes
  • Live foods (fishes, shrimps, worms): Some of Diet – Live foods can be given to wild caught specimens to get them to start feeding, or given to a breeding pair to condition them for spawning.
  • Vegetable Food: Half of Diet
  • Meaty Food: Half of Diet
  • Feeding Frequency: Several feedings per day – Feed 2 to 3 times a day as adults and 3 to 4 times as juveniles.

Aquarium Care

These clownfish are hardy and fairly easy to keep. They do well when provided good water conditions and a well maintained tank; smaller tank sizes do result in water quality degrading quicker. Although they are tolerant of less than perfect water quality, prolonged poor water quality will result in illness and disease with any saltwater fish. Regular water changes done bi-weekly will also help replace the trace elements that the fish and corals use up. 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 – Depending on the tank size, do bi-weekly water changes of 15% every 2 weeks or 30% a month, and if there are corals in the tank then 5% weekly to 15% every 2 weeks.

Aquarium Setup

The Maroon Clownfish is a one of the largest clownfish, and is quite active. It needs a minimum tank size of 30 (114 L) gallons for a single specimen, 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.

Live rock with plenty of hiding places and for them to forage from is appreciated. This clown will appreciate a host anemone or an other invertebrate or rock structure to adopt as a substitute host. If keeping within an anemone, the tank should be sized according to the anemones 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. Water movement is not a significant factor, but it needs a slow circulation in some areas of the tank to feed.

This species lives in tropical areas, so maintain aquarium water temperatures between 74°F to 82°F (23 – 28°C), and they can tolerate a pH range from 7.8 to 8.4. Keeping the tank at 82° F (28°C) seems to keep them healthier and entices them to eat more. 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).

  • Minimum Tank Size: 30 gal (114 L) – A minimum of 30 gallons is recommended for keeping one fish. A larger tank, 55 gallons or more will be needed if keeping it as a pair, with other fish, or 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. Males also need places to hide from females when they are picking on them.
  • 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 at least one area of slower water movement in the tank to enable them to feed.
  • Water Region: All – When kept with an anemone or coral they they tend to spend the majority of their time with their host, but will also swim in all parts of the aquarium.

Social Behaviors

The Maroon Clownfish is the most aggressive of all Clownfish. They can be kept in a reef setting or a fish only setting. but they can be very territorial and aggressive, They are aggressive even when attempting to form a male and female pair! Just putting two juveniles together does not always result in a pairing, but may result in death since, unlike other clownfish, they will fight among themselves. An aquarist will have better success by choosing an obvious large female and small male, but watch the aggression from the female so he does not end up bludgeoned to death. Trying a large female and several males would be suggested, but be ready to remove the ones who are not accepted and provide areas for them to hide that the female cannot fit into. Some aquarists put in an egg crate divider with a half inch opening so the male can get away from the female. They also need a rather large anemone for the male to get away from the female.

Do not keep a Maroon Clownfish with any other fish in a 30 gallon tank, because their aggressive and territorial nature will not bode well with its tank mates! They should not be kept with peaceful fish and it is not suggested to put them with other clownfish. Keep them with aggressive to semi-aggressive fish in a larger tank. These clownfish are large enough to keep with eels and fish that would otherwise swallow other clowns whole. Your basic rule of thumb is if the clown fish won’t fit in a predatory fishes mouth it should be fine.

  • Compatibility with other Clownfish:
    Due to their aggression towards other clownfish species, the Maroon Anemone 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 they 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. They will eat a few copepods here and there.
  • 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.

    Host Anemones the Maroon Clownfish is associated with in the wild:

Be cautious adding Condy Anemones Condylactis gigantea. These are very mobile, predatory anemones, and are not a “clown hosting anemone”. 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!”.

  • Venomous: No
  • Temperament: Aggressive – They are about 10 on the clownfish aggression scale of 1 to 10, with 10 being the most aggressive.
  • Compatible with:
    • Same species – conspecifics: Sometimes – Males and females may not automatically pair up. Getting several juvenies and allowing a pair to develop, then rehome or sell the remaining juveniles. This should only be attempted in a tank that is at least 55 gallons with a large enough anemone that the male can hide from the female.
    • Peaceful fish (gobies, dartfish, assessors, fairy wrasses): Threat – Maroons are too aggressive for these fish.
    • Semi-Aggressive (anthias, clownfish, dwarf angels): Monitor – Do not house with other clownfish or small anthias. Monitor dwarf angelfish.
    • Monitor – Dottybacks should be housed alone due to their aggression. Damselfish are okay only if the tank is very large, over 100 gallons and there are plenty of places for the damsels or clowns to hide.
    • 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 – They will be fine as long as they cannot fit the clownfish in their mouths.
    • Threat – Maroon Clownfish are too aggressive for these fish.
    • Anemones: Safe – Preferred anemone is the Bubble Tip Anemone. Its risky to house with Condylactis Anemones.
    • Mushroom Anemones – Corallimorphs: Safe
    • LPS corals: Safe
    • SPS corals: Safe
    • Gorgonians, Sea Fans: Safe
    • Leather Corals: Safe
    • Soft Corals (xenias, tree corals): Safe
    • Star Polyps, Organ Pipe Coral: Safe
    • Zoanthids – Button Polyps, Sea Mats: Safe
    • Sponges, Tunicates: Safe
    • Shrimps, Crabs, Snails: Safe – May eat tiny shrimp.
    • Starfish: Safe
    • Feather Dusters, Bristle Worms, Flatworms: Safe
    • Clams, Scallops, Oysters: Safe
    • Copepods, Amphipods, Mini Brittle Stars: Safe

Sex: Sexual differences

Males are smaller, reaching about 1/3 the size of the female up to a little over 5”. The females are larger, reaching over 6”. Some have reported having an 8” female, which may be possible in captivity.

Breeding / Reproduction

The Maroon Clownfish has been bred in captivity. Getting a compatible pairing is the challenge. A Maroon pair will spawn in water temperatues of 79°F to 83°F (26°C to 28°C). Feed nutritious food to enable them to lay healthy eggs. Courtship will start 3 to 5 days before spawning, and during this time the female’s belly starts to swell with eggs.

As they start to get closer to spawning, they vigorously clean an area of rock very close to the anemone, in order for the eggs to adhere correctly. The performance of various rituals such as head standing, touching their ventral surfaces, and/or leaning towards each other with dorsal surfaces touching as they shake their heads now begins.

When the female is ready to lay her eggs she will nip at the anemone so it retracts, now exposing the spawning sight. At this time she will lay her eggs, closely followed by the male who promptly fertilizes them. Spawning is known to occur late morning to early afternoon and can last up to 2 1/2 hours.

Maroon Clownfish Pair, Premnas biaculeatus
Maroon Clownfish Pair Photo © Animal-World: Courtesy Greg Rothschild

A clutch of Maroon Clownfish eggs in the wild number between 146 to 986, with an average being 480. With the above-mentioned water temperature, hatching will happen on the sixth evening after spawning (other clownfish hatch days later). The larvae ascend into the water column, and although the hatch rate is good, survival of the larvae is quite poor when compared to other clownfish species.

Within 8 to 16 days, the larvae that survive not being eaten in the wild, or in captivity ones who survive fungus or other maladies become free swimming young clown fish. Then the search for their anemone for protection and food begins. Two types of recognition of the host anemone occur when these fish are still growing in their eggs. First, there is a scent that the particular anemone emits that they have been laid by, and/or second, the visual recognition of their parents swimming within the tentacles.

In captivity, Maroon Clownfish will lay 1,500 eggs, which hatch around the 7th day. They are able to be sold at 8 to 10 months of age, and the gold striped variation can take up to a year to develop this coloring.

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 – Hatch rate of the eggs is high, but the larval rate is low.

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 Maroon Clownfish is very easy to find in stores and online and is not too expensive unless you are looking for designer patterns.