Oman Anemonefish

The Oman Anemonefish is one of the largest and rarest clownfish, and definitely a prize worth seeking!

The Oman Anemonefish Amphiprion omanensis, also called the Oman Clownfish, one of the largest clown species. It has a stout rounded body that will reach just over 6 inches in length (15.5 cm). Its body color can be orange to reddish brown with two very narrow vertical bars, one at the head and the other mid-body. It is also called the Oman Clownfish and reportedly in Japan, it may be called he Blue-Band Clownfish. There is an rare variationthat has abright brick red coloring on the body and tail fin, which is called the Brick Red Oman.

This clownfish is one of the 11 species grouped in the Clarkii Complex.and is one of the newest clownfish arrivals. It wasscientifically described as recently as 1991. The members of the Clarkii group are generally geographically widespread so a number of species are regularly available to aquarists. But this species is very localized with a small distribution. It is found in the Western Indian Ocean off the coast of Oman at the tip of the Arabian Peninsula, and just north of the Socotra (Sokotra) Island. They are hard to acquire since collection from the Oman Peninsula is restricted. Consequently this is a very rare clownfish to come across in aquaria, and if it is available it will be very expensive.

Like the common Clark’s ClownfishAmphiprion clarkii, this fish has a longer, forked tail that gives it the ability to swim quicker than other types of clowns. But this clownfish is a very distinctive because its caudal fin has a strongly forked lyre shape with filaments streaming from the ends of the tailfin’s lobes. This fin is typically white while the pelvic and anal fins are always dark brown. This is one of only two clownfish with such a distinctly forkedcaudal fin. The other is the Madagascar Anemonefish Amphiprion latifasciatus, another very rare species that also lives in the Western Indian Ocean. The Madagascar is found from Madagascar and the Comoro Islands,but it has a much broader mid-body stripe than the Oman Anemonefish.

The Oman Clown is easy to care for anddoesn’t have any special care requirements. So if you can findand purchase one, itwould be a good, hardy choice for both beginners or more advanced hobbyists. It will do well in a either a coral-rich tank or in a fish only tank. It will need to be provided iwith an anemone host or other invertebrates in a reef tank, or with some rock structures in a fish only aquarium.

Like others in the Clarkii complex, theseclownsare less dependent on a host anemone. In the wild it will often prefer to hide in a reef crevice if frightened. Though in the wild they are associated with anemones they will readily adapt without one, and may even adopt a rock structure or other invertebrate as a substitute host. Soft corals and Euphillia species are some that may be accepted if there is no host anemone available. Since it swims a little more than most clownfish, providing it with an open area to swim will also be appreciated.

They get along with most fish as long as their tankmates are not large enough to swallow them. They shouldn’t be housed with very aggressive fish like Dottybacks, nor housed with peaceful fish in a smaller tank. Buying two clownfish that are different sizes, or two young juveniles will eventually result in a male-female pair. However all clowns from the clarkii complex are aggressive and should not be housed with other species of clownfish. One interesting fact about clownfish is that they make chirping or popping noises that can be heard outside the tank. Some species are louder than others, and it is thought that each species may have their own dialect.

A minimum tank size of at least 30 gallons (114 l) is required for a single fish. A larger tank, 55 gallons or more, would be needed if keeping a pair or if keeping it with other fish. If attempting to keep it with an anemone, choose the tank size according to the anemone’s needs, not the clownfish. Feed your Oman Anemonefish a wide variety of foods that are both meaty and vegetable based. An area in the tank with very little current will be needed for them to comfortably feed. They don’t have any specific lighting needs, unless of course they are kept with an anemone. Once they are acclimated to the tank they should swim at all levels.

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

Habitat: Distribution / Background

The Oman Anemonefish Amphiprion omanensis was described by Allen and Mee in 1991. This is one of the newest clownfish to be scientifically described. They have a small and limited distribution within the Western Indian Ocean, in the area of the Arabian Sea. They are found off the Arabian Peninsula, the typical locality is Barr Al Hikman, off the east coast of Oman, and they have also been found just north of the Socotra (Sokotra) Island. It is thought that they have a very short larval stage, contributing to this limited dispersal. They are not listed on the IUCN Red List.

These clownfish are known by the common names Oman Anemonefish or Oman Clownfish, which have to do with their very limited habitat. There is also a rare variation with a bright brick red coloring on the body and tail fin which is called the Brick Red Oman. They are one of 11 clownfish in the Clarkii complex, which are all some of the best swimmers of all clownfish complexes.

They occur in small aggregations on inshore reefs at shallower depths between 6 – 33 feet (2 – 10 m). They have been known to associate most commonly with the clown-hosting anemones Entacmaea quadricolor, Heteractis crispa, and Heteractis magnifica, but may also possibly be hosted by the anemones Heteractis aurora and Stichodactyla mertensii. They are usually found as adult pairs. Juveniles can be found alone, or sharing an anemone with an adult pair. Anemonefish are opportunistic eaters, feeding on zoo plankton, benthic algae and weeds, small shrimp, amphipods, polychaete worms, and other small invertebrates.

• Scientific Name: Amphiprion omanensis
• Social Grouping: Varies – Typically found as adult pairs. Juveniles alone or with adults in same anemone.
• IUCN Red List: NE – Not Evaluated or not listed

Description

The Oman Anemonefish is a deep bodied clownfish from the Clarkii Complex, but with a very distinct look. These fish typically have a stout, rounded body and a forked tail, which helps them to swim faster than other anemonefish that have rounded tails. But its distinctive tail fin has a strongly forked, lyre shape with filaments streaming from the ends of the tailfin’s lobes. Females can grow to 6.1†(15.5 cm), and males are much smaller. Similar to others in the clarkii complex, the Oman Anemonefish will probably live about15 years in captivity.

Adults have an orange to orangish brown, or reddish brown body with a head that is paler, almost tan. There are two vertical white bars on its sides, one located just behind the eye and the other mid-body. These bars are very narrow, which is quite distinct from other clownfish. On adults the bar at the head area usually does not reach across the nape, nor does it extend all the way down to the very bottom of the chin, as seen in other clownfish. The second stripe is narrower than the first and typically on adults it does not extend onto the belly area. At times large adults will simply lose the mid-body bar or there may only be a slight remnant of it near the dorsal fin. The tail fin is typically white while the pelvic and anal fins are always dark brown to black.

Juveniles are light brown though yellow ventrally with two white bars on the sides. There is also one variation called the Brick Red Oman, which is a brick red coloring on the body and the tail fin is also brick red.

• Size of fish – inches: 6.1 inches (15.49 cm)
• Lifespan: 15 years – Longest recorded lifespan for Clarkii complex is 15 years in captivity. They have been reported to live 13 years in the wild.

Fish Keeping Difficulty

The Oman Anemonefish, like all Amphiprion members are very hardy. They are generally easy to keep and can be recommended for beginners. No special care is needed to feed this fish as it will take a variety of foods. It does need some crevices to retreat into, and also lots of open space to swim freely. They are quite resistant to most infectious diseases and seldom suffer from infections.

As with any clownfish purchase, make sure that they are feeding and do not have any signs of infection or labored breathing. Avoid fish that have excess slime mucus or white casting on their back. Small white spots over their body and fins is a warning sign of Crypt and these specimens should be avoided.

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

Foods and Feeding

The Oman Anemonefish are omnivores. In the wild the Amphiprion members eat zoo plankton, benthic algae and weeds, small shrimp, amphipods, polychaete worms, and other small invertebrates. In the aquarium this fish will readily accept a wide variety of foods; including live foods, frozen and flake foods, algae, meaty foods, shrimps, and may feed on tablets. a variety of finely chopped meaty foods, minced fish or shrimp can be fed regularly. Also provide a variety of vegetable source foods in pellet and flake form, and they will eat most naturally growing algae in the tank.

It does not generally harm live corals or small inverts, but large adults may attack ornamental shrimps. They will also pick at the dead tentacles of their host anemone. Feed twice a day as adults, but juvenile should be fed or four times a day, and whatever they will consume in about 3 minutes. 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 – Gut loaded live foods can be fed as a treat periodically or to help them get into breeding condition.
• 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 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. Although Oman Clownfish are tolerant of less than perfect water quality, prolonged poor water quality will result in illness and disease with any saltwater fish, hardy or not. 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 – Do 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 Oman Anemonefish 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 or if keeping it with other fish. 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.

These clownfish arealways very actively swimming, and will venture to the surface for foods when well acclimated. Clownfish can be kept in either a saltwater aquarium or a mini reef. This fish needs open space for free swimming, but it also needs nooks and crannies to retreat into. A saltwater aquarium well decorated with rocks/ corals will provide it with many places for retreat. In the wild these clowns are associated with anemones, but they don’t need an anemone host in the aquarium. They will readily adapt to a salt water tank without one. Although they will appreciate a host anemone, often they will use a coral or other invertebrate, or even a rock structure, as a substitute.

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. 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).

It has no special lighting requirements though if kept with a host, the anemone will need strong lighting. Water movement is not a significant factor, but it needs at least a slow circulation in the tank to feed. They will spend the majority of their time in their host, though the Oman Anemone, like others in it’s complex wanders from its host on a whim.

• 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.
• Substrate Type: Any
• Lighting Needs: Any – It has no special lighting requirements though if kept with a host, the anemone will need strong lighting.
• Temperature: 74.0 to 83.0° F (23.3 to 28.3&deg C)
• Breeding Temperature: 79.0° F – Although members of the Clarkii Complex will spawn between 72°F to 88°F (26° – 28°C), 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 or coral they tend to stay in the same vicinity, but will also swim in all parts of the aquarium.

Social Behaviors

The Oman Clownfish is moderately assertive. This fish will do well in either a reef setting or a fish only setting. It is mainly reef safe but adults may occasionally chew on polyps of some live corals. Like all anemone fish they can be territorial and aggressive, especially as they get older. They can get along together with a variety of fish that are assertive but not overly aggressive, providing the aquarium is large enough to provide them with a place of their own to defend.

Though they get along with most tank mates, once an adult pair has bonded with an anemone, other fish will be chased away. Some docile damselfish or other peaceful fish will be harassed by the Oman Anemonefish in small tanks, so 55 gallons or more would be necessary if keeping with these fish. Conversely, dottybacks will be too aggressive toward your clownfish. With an anemone, they can tolerate the semi-aggressive fish. Do not house with fish large enough to swallow it.

• Compatibility with other Clownfish:
  Due to their aggression towards other clownfish species, the Oman Anemonefish 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 Oman Anemonefish will still thrive.
• 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 Oman Clownfish is known to associated with:
  • Bubble Tip Anemone Entacmaea quadricolor
  • Magnificent Sea Anemone, Ritteri Anemone Heteractis magnifica
  • Sebae Anemone Heteractis crispa
  
  They may also associate with these clown-hosting anemones:
  • Beaded Sea Anemone Heteractis aurora
  • Merten’s Carpet Anemone Stichodactyla mertensi

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 – On a scale of 1 to 10 the aggressiveness of this clown is about an 8 or 9 in comparison with other clown fish.
• Compatible with:
  • Same species – conspecifics: Yes – Can be kept as a male/female pair or as two sub adults.
  • Peaceful fish (gobies, dartfish, assessors, fairy wrasses): Monitor – The Oman Anemonefish will be aggressive towards these peaceful take fish in a smaller tank under 55 gallons. 

  • Semi-Aggressive (anthias, clownfish, dwarf angels): Safe – Do not house with other clownfish.
  • 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 – 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 – Do not house with Condylactis Anemones as these are not clown hosting anemones and may eventually kill and eat your clownfish. Caution with Carpet Anemones for similar reasons.
  • Mushroom Anemones – Corallimorphs: Safe – Large mushrooms such as Elephant Ear Mushrooms (Amplexidiscus fenestrafer) can trap and eat a juvenile clownfish.
  • 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: Monitor – Similar to the Clark’s Clownfish, some in this complex have been known to drag an unwary shrimp into its host anemone.
  • Starfish: Safe
  • Feather Dusters, Bristle Worms, Flatworms: Safe
  • Clams, Scallops, Oysters: Safe
  • Copepods, Amphipods, Mini Brittle Stars: Safe

Sexual differences

The female is usually much larger than the male.

Breeding / Reproduction

Though many clown fish species are now being captive bred, the Oman Anemonefish has not yet been reported to have been bred in captivity. No record for aquaculture at any laboratory is known. Similar to others in the Clarkii complex, they will spawn when the water temperature is 74° or higher. Although they will spawn between 72° – 88° F (26° – 28° C), it has been demonstrated that the best quality eggs and larvae happens when the temperature is 79° – 83° F (26° – 28° C).

Three to five days before spawning, courtship begins when the female spurs the male into biting at the substrate in increasing frequency and intensity as the big day draws closer. During this time the female belly swells with eggs. Clownfish displays performed during courting include leaning away from each other so their ventral surfaces are close, leaning towards each other with their dorsal surfaces close while shaking their heads, and/or one or both will engage in head standing.

Once the pair has decided on a spawning site, they will meticulously and neurotically clean the surface for proper egg adhesion. The area is generally close to the anemone, which provides the protection of its tentacles. Just before spawning, the clown fish pair will pick at the anemone to cause it to retract, exposing the full spawning site. The female presses her belly against the surface, quivers and drags herself along the surface, leaving a trail of eggs and will continue this in a circular pattern until she has laid all of her eggs. The male will then come up behind her and fertilize the eggs.

Spawning occurs late morning to early afternoon and can last up to two and half hours with the clutch of eggs numbering on average between 100 to 2500, depending on the size of the female. The eggs are fanned and mouthed to keep them free of fungal infections, debris, and to keep them well oxygenated as they develop. Within 6 to 13 days, depending on water temperature, these 2.2 to 4.4 mm long, orange eggs will hatch 1 to 1.5 hours after sunset. Interestingly, the Oman Anemonefish will all hatch within two hours. The larvae swim into the water column and enter the planktonic stage is typically shorter for this species than for most clownfish species. It is thought that the Oman Anemonefish has a short larval stage due to its limited distribution. This means it may be closer to only 6 to 8 days, although more research needs to be done.

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: Unknown

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 tankmates. 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.

Availability

The Oman Anemonefish very rarely enters the aquarium trade. These fish are very hard to find and are quite expensive. At times, they may be mislabeled as another species of clownfish, so knowing their distinct markings is an advantage

Featured Image Credit: JonMilnes, Shutterstock