Book Excerpt: Clownfishes: A Guide to Their Captive Care, Breeding, and Natural History

Author: Joyce D. Wilkerson

Nemo may be the most popular clownfish, but there a large variety of clownfish species available. In this TFH-exclusive book excerpt, an accomplished clownfish breeder profiles the natural history and care of various species:

The 28 clownfish species fall into six broad groups, called complexes: the Percula Complex, the Tomato Complex, the Skunk Complex, the Clarkii Complex, the Saddleback Complex, and the Maroons.

The Percula Complex

Amphiprion ocellaris clowns are the icons of the marine aquarium hobby. Their pictures grace book and magazine covers, as well as advertising logos, T-shirts, and stationery. Ocellaris Clowns vary in color from dandelion yellow to tangerine and have three white bands bordered in black. Adults grow to slightly over 3 inches (80 millimeters) standard length (not including the tail fin). As is characteristic of most clownfish pairs, a male Ocellaris is smaller than a female, reaching only about three-quarters the length of its mate.

These personable fish are readily available but are often confused with A. percula. Although it is not a definitive test, A. percula clownfish usually have wider black bands bordering their white bars, particularly notable at the top rear of the head bar.If you put an Ocellaris and a Percula in tanks near each other, you may be able to tell one from the other by color pattern. It’s not always a matter of simply looking at them to tell these two species apart, and it would seem that even the fish themselves have some difficulty distinguishing one another, because they will crossbreed. Both A. ocellaris and A. percula are now being tank-raised and bred selectively to amplify their distinguishing characteristics. This may make species identification easier in the future.

Amphiprion ocellaris are among the easiest clownfishes to rear; they can be kept in tanks as small as 10 gallons (38 liters) and will even spawn in them. They are inordinately mild-mannered fish, and unlike other species in this genus, you can safely keep several A. ocellaris in the same tank; all other clownfishes are far less tolerant of the same species sharing their nesting area. However, no more than one spawning pair will form in an aquarium. In one of my aquariums, I have four A. ocellaris; which I’ve nicknamedMom, Pop, Nursemaid, and Goaway. Nursemaid is the heir apparent and helps tend eggs. Goaway shares the aquarium but only at a safe distance.

There is a solid demand for tank-reared Ocellaris, because the species is popular and because wild Ocellaris do not ship well. Far too often, wholesalers and retailers buy wild Ocellaris only to watch helplessly as 50 to 100% of the fish succumb to shipping stress within the first week of arrival. The cause is thought to be a susceptibility to bacterial or viral infections exacerbated by overcrowding. Avoid purchasing an Ocellaris that has been recently received and is either lethargic or swimming frantically at the water’s surface. Aside from susceptibility to shipping stress, Ocellaris are hardy and acclimate quickly to aquarium conditions. Their primary defense is to acquiesce in the face of challenges. They seem to realize that they are not large enough to offer much of a fight.

Ocellaris are one of the poorest swimmers of all the clownfish species; they choose a small territory in the aquarium and seldom stray far from it. Even at feeding time, they may pass up foods dropped too far from their security zone. The male and female of a pair are usually inseparable. Males are covetous of their eggs and may go into a “rage” upon noticing that their eggs have been swiped by the human caretaker intent on hatching them in a separate tank. It takes hours or days for them to forget their loss, after which they return to their normal genial behavior.

Ocellaris larvae accept brine shrimp earlier than do most clownfish larvae; rotifers (zooplankton) are their primary food for only about the first four days. They metamorphose from larvae to juveniles early as well, sometimes completing metamorphosis in as little as six days after hatching.

Ocellaris juveniles reach marketable size in about five months. Inquisitive by nature, juveniles of this species will often swim to the surface of their tank when approached, and even push an eye above the water, seemingly for a better view. If there is a downside to raising Ocellaris Clowns, it is only that they are too difficult to part with.

No clownfish species schools in nature, but as small juveniles in home aquariums, Ocellaris school in a tightly packed mass at night or when frightened, a defensive behavior designed to give the illusion of a single large organism and thus dissuade predators from attacking. Other explanations offered for such schooling suggest that it reduces the chances of any single fish being eaten (dilution effect) and/or that predators have a hard time targeting a single individual in a tight group (confusion effect). I’ve seen upwards of 200 A. ocellaris in a single clump smaller than my fist when I’ve sneaked to their tanks at night just to look at their peculiar array. The clump resembled a drifting blob of orange gelatin.

It seems fitting that A. ocellaris, perhaps the most popular of all marine fishes, was the species reared by Martin A. Moe, Jr. in the early 1970s, signalling the possibility of commercially culturing ornamental marine fishes.

Amphiprion percula, Percula Clownfish

Amphiprion percula clownfish are also very poor swimmers and seldom venture outside of their small territory to scout around the tank. I have one pair that, as far as I have seen, has not ventured more than 6 inches from their homesite in years. They are stuck in their comfortable rut.

Insecure Perculas may hide and remain hidden for a day or two, or even a week. Many times I’ve torn down rock pile homes to find a sulking Percula holed up. Increased security presumably comes with size.

Percula Clown males can be hopeless female-chasers, preferring to pursue their mates rather than tend to their eggs. For one Percula pair that I keep, I routinely take and artificially incubate their eggs within a few days of their being laid because the male is too distracted to keep the eggs aerated. If a Percula male is tending his eggs properly, leave them to his care, but if you notice a substantial number of eggs disappearing from the clutch each day, suspect that the male’s allegiance to his mate is overwhelming his paternal behavior and take the eggs away early.

Percula Clowns are similar in appearance, keeping, and culture to A. ocellaris, except that Perculas seem to need better water quality and grow slower, taking up to a year to reach marketable coloration. During that time, they grow into their stripes, but even at a year old, the white tail stripe may remain incomplete. They are the smallest of all the clowns, reaching only 2 inches (64 millimeters), and a 10-gallon (38-liter) tank is adequate for them.

Due to selective breeding of hatchery stocks, tank-reared Percula Clownfish are readily available in several color variations, including tangerine, bittersweet (or dark orange), and nearly black. A striking bright red strain and a black strain have been set in Perculas at the C-Quest Hatchery in Puerto Rico.

Physically, there is little difference between Ocellaris and Percula Clownfishes. Generally, Ocellaris Clowns have 11 dorsal spines while Perculas have just 9 or 10, but this is not always true, and believe me, it is very difficult (impossible for most of us) to count them on a live fish in an aquarium. Ocellaris Clownfish commonly have 17 pectoral rays while Perculas usually have 16, but they can range from 16 to 18 on Ocellaris Clowns and from 15 to 17 on Perculas. According to Fautin and Allen, the anterior part of the dorsal fin ray is taller on Ocellaris than on Percula, but the difference is scant.

These two species also act differently: Ocellaris Clowns usually live in the middle third (vertically) of an aquarium, while Perculas live near the surface. It can be challenging to make either one of these species settle into a territory away from the surface. I’ve sometimes had to suspend conch shells and rocks from glass bars placed across the top of the tank to encourage them to give up their itinerant lifestyle.

In nature, according to Fautin and Allen, Perculas occupy a smaller geographic region than do Ocellaris. Between these two, specimens caught from the wild are more likely to be Ocellaris, which is found widely in Indonesia and the Philippines, the two leading marine fish exporting countries.

While Ocellaris Clowns are usually mild-mannered, I have found that wild Perculas can be gangsters that attack tankmates and keepers. Tank-reared Perculas, however, are amiable towards their custodians, bobbing about the water’s surface when greeting their owner, but they remain hard-hearted towards tankmates. Even Maroon Clownfish, known for being intolerant of other clowns, can be held at bay by a tank-reared Percula, an odd tournament to witness, since Perculas are the smallest clownfish while Maroons are one of the largest.

One interesting Percula quirk: the juveniles keep their top fins oriented towards the strongest light. You can confuse them by moving the overhead tank lights to the side, causing them to “stand on their heads” to keep their top fins oriented toward the light source.

The Tomato Complex

The adults of the Tomato Complex are large, oval-profiled or deep-bodied, and powerfully built.

Amphiprion melanopus, Red and Black (Cinnamon) Clownfish and A. frenatus, Tomato Clownfish

Red and Black and Tomato Clownfish are excellent beginners’ fishes, physically robust, hardy, and readily available. Both species have healthy appetites and feed well, avidly accepting aquarium foods. Female Red and Black Clowns reach 3 inches (90 millimeters), and Tomato Clowns can be over 4 inches long (110 millimeters). The females are large, so give them a roomy tank—over 40 gallons. Males of both species are much smaller, reaching only about half the length of their mates. (For every clownfish generality, it seems, there are nonconformist individuals. I have seen more than one spawning pair of Tomato Clowns where the male was as large as its mate.)

Tomato Clownfish range in color from burnt orange to tomato red. As females mature, they turn dark brown from the eye to the tail, but their faces remain bright orange or red, and all of their fins retain their bright hues as well. Male Tomato Clowns keep their youthful bright red coloring throughout life. Two strains of Tomato Clownfish are available: blue-striped and white-striped. It may take a little studying to detect the blue in the stripes of the young ones, however. Very young specimens have three stripes. Sometimes you can find them with their juvenile striping, but all clowns from the Tomato Complex grow out of their stripes—their tail and midbody band white stripes recede until only the white head band remains.

Juvenile Tomato Clowns fight each other more tenaciously than most Amphiprion clowns, and placing more than two in one aquarium invites harm to weaker individuals. As adults, female Tomato Clowns are vicious, more so to people than to other fishes. They are quick to bite the hobbyist intent on tank maintenance. On the other hand, they are not too picky about mates and will spawn with other members of the Tomato Complex.

Red and Black Clownfish are a burnt orange color as juveniles. Adults have just one stripe at the head, but juveniles of this species (like all Tomato Complex juveniles) have three. Mature Tomato Clowns possess red pelvic and anal fins, whereas mature Red and Blacks usually have black pelvic and anal fins. (Localized patches of Red and Black Clownfish are distinctly colored, sometimes revealing their origin. Specimens of A. melanopus from Polynesia, Fiji, and Tonga have red pelvic and anal fins, not black. Coral Sea adults lack head bands. These are less frequently seen in the aquarium trade.) Either blue-striped or white-striped Red and Black strains are available.

Both Tomato and Red and Black Clownfish are species I would include on an easy-to-rear list. Their larvae quickly become skilled hunters, and juveniles readily accept numerous foods. Juveniles are fleet little fishes that get excited at feeding times and avidly attack their prey. They also tolerate inferior water conditions.

A. rubrocinctus, Australian Clownfish

There are three similar, less commonly available species in the Tomato Complex. One is the Australian Clownfish, A. rubrocinctus, which is burnt orange with a white head band stripe that lacks a pronounced black margin in adults, in contrast to the black border around the white stripe on both Tomato and Red and Black Clowns. The fins, nose, and belly are red in the Australian Clownfish. In my experience, these are not as hardy as the more popular Tomato, Red and Black, or Red Saddleback Clowns.

A. ephippium, Red Saddleback Clownfish

The second similar species is the Red Saddleback Clown, A. ephippium, which is the only clownfish that usually lacks any striping as an adult. They do, however, have a white head band stripe that persists throughout their juvenile lives. Red Saddlebacks are yellowish orange, with a mahogany-colored dot that develops on the fish’s flank as it matures. Initially about the size of its eye, this dot grows and eventually covers nearly half the fish’s body. The tail and rear dorsal fin may become mahogany-tinted as the fish matures.

Red Saddlebacks are bold and hardy fish, but they are unique among clowns in their nearly complete intolerance to being treated with copper. Copper medications cause high mortality as well as skin lesions. (If copper must be used, limit its application to two days and follow the treatment with an antibiotic.) For this reason, they are probably not a good species choice for a novice aquarist.

A. mccullochi, McCulloch’s Clownfish

The last member of the Tomato Complex is McCulloch’s Clownfish, A. mccullochi. These clownfish are dark brown or black with a white face, irregularly shaped white “sideburns,” and a white tail fin. They are extremely rare, and information is scarce on their hardiness. They are indigenous to a few islands off eastern Australia (Lord Howe Island Group and Norfolk Island), which are part of the most southerly coral reef in the world. If a hobbyist happens upon one of these specimens and decides to purchase it, a relatively low tank temperature would be appropriate, befitting its subtropical origins. Interestingly, the other dark brown (almost black) and white clownfish, A. latezonatus, is also indigenous to the Lord Howe Island Group.

The Skunk Complex

Skunk clowns are streamlined, like Ocellaris and Percula Clowns, with a body length two to two-and-a-half times longer than their maximum body height.

The three skunk clowns are all hardy but tend to be nervous and edgy. If they are to be part of a community of fishes, add them to the aquarium early and give them a chance to claim an area before introducing other territorial fishes. Once they have settled, they become bolder and may defend their territory. If added to a tank already containing harassing fishes, they will remain apprehensive wanderers and never settle. They are vigorous—suitable for beginning aquarists but not the best choice for beginning breeders, as they are difficult and unreliable spawners. Habitually, they spawn a few small hatches, then stop spawning for months or even years. Like Ocellaris and Percula Clowns, their clutches contain only a few hundred eggs. I have not seen any of them spawn in a tank smaller than 40 gallons.

The easiest of these three to identify is the Pink Skunk, A. perideraion, which has a narrow white head band and a white dorsal stripe on a pale pink to peach or pinkish yellow body. Males and females of this species are similar in size. Males retain pink borders on their tails and soft dorsal fins but females have whiter fins. The tail fin on A. akallopisos is generally white, but on A. sandaracinos, it is apricot-colored, like its body. Pink Skunks are the smallest skunk clownfish, reaching only 3 inches (75 millimeters) in length. The Skunk Clown, A. akallopisos, reaches 3 inches (85 millimeters); at maturity, A. sandaracinos may be over 4 inches long (110 millimeters).

Amphiprion akallopisos, the Skunk Clown, and A. sandaracinos, the Orange Skunk Clown, both have a distinguishing white dorsal stripe but no head bar. The Orange Skunk has a wide, white dorsal stripe that butts against its top lip on a gleaming apricot-colored body. The stripe begins bluntly on its mouth, as if it were wearing white lipstick, and runs boldly and broadly to its tail. On A. akallopisos, the stripe is narrow and ends in a point, short of the mouth, and the body color is similar to that of the Pink Skunk.

A. nigripes, Maldives (Black-footed) Clownfish

Amphiprion nigripes is a species similar to the skunk clowns. It lacks a white dorsal stripe, but has a white head band with black margins on a body colored dandelion yellow to burnt orange. Uniquely, it has black pelvic and anal fins, making it look as if its lower body had been dipped in black paint. If you want this clownfish, you may have to ask your dealer to special-order it for you. A word of caution: these are intolerant of shipping stress and are one of the least hardy clowns. They are a bit small, with adult females reaching just over 3 inches (85 millimeters) long. Males are nearly as large as females. The larvae of A. nigripes are sensitive to strong light.

A. leucokranos, White-bonnet Clownfish

Amphiprion leucokranos is another skunk clown kindred species. It rarely appears in the aquarium trade and is not hardy by clownfish standards. Although their “classic” design features a teardrop-shaped white dorsal splash near the head (the “bonnet”) and matching white splashes of color just behind the eyes on an apricot-colored body, their color and striping can be highly variable. They range in color from tan to brown to orange to pink. Siblings may have no white dorsal stripe, a full length dorsal stripe, or anything in between. The head stripe can be wide or narrow, partial or complete, white or blue.

These are the precious “mutts” of the clownfish family and are almost certainly hybrid offspring crosses between A. chrysopterus and one of the skunk clowns, probably A. sandaracinos. Maximum length for this fish is 3 inches (90 millimeters).

If you happen to see this fish and want it, you may need to make arrangements to buy it at once, as they are seldom available. Being rare, they should fetch a hefty sum for those who can supply the aquarium market, but remember that the offspring may not all look like their parents. Regardless, it should be fascinating to see what sort of variations you get from a pair of White-bonnets.

A. thiellei, Thielle’s Clownfish

Amphiprion thiellei, Thielle’s Clown, has been a provisional species since two were discovered in a New Jersey aquarium in 1981. This is almost certainly a naturally occurring hybrid or a variant of some other species. Their refined facial features remind me more of A. perideraion than of squarer-jawed A. sandaracinos. Traditionally, A. thiellei have a complete head stripe, whereas A. leucokranos have incomplete head bars. However, those who have raised A. leucokranos in captivity report offspring with similar color and striping to A. thiellei. As a rarity, Thielle’s Clowns should be left in the ocean or collected only on a restricted basis for scientific study, documentation, and breeding.

The Clarkii Complex

There are many species similar to the widespread Clark’s Clownfish. All of the impostors, and Clark’s as well, are included in the Clarkii Complex, a group that encompasses 11 of the 27 Amphiprion species. At this writing, many of these are still being incorrectly labeled “Sebae” Clownfish by distributors and retailers. (The true Sebae Clownfish is exceedingly hard to obtain. Amphiprionsebae is not even a member of the Clarkii Complex—it belongs to the Saddleback Complex, discussed below.) In fact, any yellow-and-white-striped clownfish might be sold as a “Sebae” Clown. True Sebae Clownfish, A. sebae, are easy to distinguish from Clark’s Clownfish: the upper portion of a Sebae Clownfish’s midbody band tilts diagonally back, while a Clark’s midbody band is more vertical. In addition, Sebae Clownfish have only a head and a midbody band.

Sebae Clownfish occur in the wild outside the usual collecting areas, and they are rarely available. In contrast, Clark’s Clowns are the most geographically widespread of all the clownfishes, occupying a vast area of the Indo-Pacific, perhaps because they are compatible with all of the ten clownfish-hosting sea anemones found there. For this reason, and because they are now tank-reared in quantity, Clark’s are far more available in the aquarium trade than Sebae Clowns, or any other yellow-and-white-striped clown, for that matter.

Amphiprion clarkii, Clark’s Clownfish

Amphiprion clarkii are big, bold, striking fish, and they are hardy, even by clownfish standards. Whoever started the rumor that male clownfish are always smaller than females apparently did not rear Clark’s Clowns, for both sexes of this species are nearly identical in size. Males and females can exceed 4 inches (100 millimeters) in length.

Being comparatively large, they need a spacious 40-to-50-gallon (150-to-200-liter) spawning tank. Clark’s Clowns adapt well to their glass oceans, are the fastest growing of all the clownfishes, and seem to fake constant hunger, begging for handouts from the aquarium keeper at every opportunity.

Clark’s Clowns are recommended for beginning hobbyists and breeders for several reasons. They are tough fish and can withstand some water quality abuse. Perhaps because they are strong swimmers by clownfish standards, they are more often out and about, rather than hovering in one small area, and easily gain control of their territory. They can hold their own and spawn successfully even when being harassed by the dogging damselfishes often used in aquarium startups. Clark’s Clownfish spawn regularly and produce large hatches. The eggs are not hidden away but are out in the open, often even on the front glass of the aquarium. Clark’s males fan their eggs vigorously during hatching. While Ocellaris eggs may take hours to hatch, Clark’s usually finish hatching within 30 minutes.

The coloring of Clark’s Clown adults is highly variable, ranging from yellow to brown to nearly black. Adults of this species may have either two or three white or gray bands (the tail band is missing on some). Often a female’s tail fin changes from yellow to white as she matures, but males retain at least some yellow in their tail fins, even if it is just a yellow edge.

Clark’s Clownfish larvae hatch with healthy appetites and, when properly fed, are not as prone to starving within the first 72 hours as are other clownfish larvae. In fact, Clark’s larvae have the opposite problem: they try to swallow food that is too big for their mouths. They may even choke on a few of the things they are bold enough to try to swallow. Mine seem to overeat if they are provided with newly hatched brine shrimp too soon. Because they are so voracious, getting them to 1 week old is not difficult. Shepherding them through metamorphosis, however, is difficult because of their need for near-perfect water quality at this stage. Once they metamorphose, they are hardy, easy to grow, and sibling fighting is not problematic. Juveniles are a little aloof and seem afraid you might harm them, but they become bolder as you gain their confidence. Food is the correct currency for buying their trust.

The marketability of Clark’s fluctuates. One month, the bright yellow Clark’s will be the rage, and the next month, the brown variety will be in demand. A single pair generally produces either all bright yellow juveniles or all dark yellow-to-brown juveniles. These fast-growing clowns can be marketed at 3 to 4 months of age. With one pair of Clark’s, you can easily produce enough clowns to flood a local market, because their clutches contain upward of 1,500 eggs. One or two successful hatches can keep you in the fish-peddling business for months.

A. akindynos, Barrier Reef Clownfish

Amphiprion akindynos is one of the seven Clark’s Clownfish look-alikes that have two white body bands as adults, one at the head, one at midbody, and none at the tail. (Juveniles may have three bands, but eventually grow out of their tail stripe.) These are a beautiful golden sienna color with thin white bars and a white or grayish tail fin. They are available if you are patient or if you special-order them, but they are not the hardiest clowns, so you may want to ask your dealer to hold them a couple of weeks before you bring them home. Barrier Reef Clowns, once settled in, adapt well to captivity. The males are as large as the females.

A. allardi, Allard’s Clownfish

Amphiprion allardi is from the East Coast of Africa and is very similar to Clark’s Clownfish. Allard’s Clowns may have nearly black bodies when they are adults, but they lack the black pigment in their yellow pelvic and anal fins. The midbody stripe on an Allard’s Clownfish is narrower than a Clark’s center stripe. Allard’s and the Orange-fin Clownfish (A. chrysopterus) look very similar, but the shape of the head stripe may help you distinguish between them: Allard’s head stripes are wide at the top and pointed at the bottom, while Orange-fins are widest not on top, but behind the eyes, and the stripe points forward at the bottom. Allard’s Clowns are rare but can be obtained with some diligence. Juveniles have brown or yellow tail fins capped in white.

A. bicinctus, Two-band Clownfish

Amphiprion bicinctus clowns vary in color from dandelion yellow to sienna. Their natural distribution range includes the Red Sea, the Gulf of Aden, and the Chagos Archipelago. Their head bands are wedge-shaped, with the widest part at the top of the head, projecting forward to their eyes, creating the appearance of white scarves worn on their heads. Females are larger than males. Two-band Clowns have been difficult to obtain, but are becoming more available with increased collection in the Red Sea.

In 1976, when H.W. Fricke was first discovering that male clowns could change into females, he removed a female A. bicinctus from an established pair. Within 26 days, the previous male laid eggs. Despite his apparent ease in spawning them, my experience with A. bicinctus is that they are reluctant spawners.

A. chagosensis, Chagos Clownfish

A small, virtually unattainable species is the Chagos Clownfish, A. chagosensis, found only in the remote Chagos Archipelago in the middle of the Indian Ocean, with a recent report from the northern tip of the Red Sea.Its head band is thin or broken on top and it has a little black smudge on its belly just above its dark gray pelvic fins. Chagos Clownfish resemble pale A. nigripes (which occur north of the Chagos Archipelago) with an added thin center stripe similar to A. bicinctus. Could these possibly be yet another hybrid?

I have never seen a Chagos Clownfish offered for sale, and they are currently regarded as nearly impossible to acquire. If you want to special-order them, you may have to convince your dealer that they really do exist and even then he may not be able to locate a source.

A. chrysopterus, Orange-fin Clownfish

Blue bands, bright yellow dorsal fins, and boxy white tail fins are common attributes of the Orange-fin Clownfish (A. chrysopterus), the largest of the Amphiprion species, with mature females reaching 5 inches (125 millimeters) in length. In comparison, Clark’s Clownfish usually have white or gray bands, a tail band, and less contrasting dorsal fins than Orange-fin Clowns. The Clark’s Clowns are also hardier.

Amphiprion chrysopterus may cross with the Orange Skunk Clownfish, A. sandaracinos, to produce the White-bonnet Clownfish, A. leucokranos.

Amphiprion chrysopterus has a widespread distribution in the Western Pacific, from Taiwan to Polynesia.

A. omanensis, Oman Clownfish

The last of the Clark’s impostors with two bands is the Oman Clown, A. omanensis. It has a sweeping, forked tail fin and black or dark chocolate pelvic fins. This species has a small distribution at the tip of the Arabian Peninsula off the coast of Oman, near the Persian Gulf. I have never seen one offered for sale, and it is so rare as to be regarded by some as unattainable. Its distinctive appearance makes it an interesting prospect for the intrepid clownfish breeder able to obtain broodstock.

A. latifasciatus, Madagascar Clownfish

Another rarity is the Madagascar Clown (A. latifasciatus), which has yellow fins, nose, and belly and a slightly forked tail fin. As its common name indicates, it is found around Madagascar, off the east coast of Africa and is a species most hobbyists will never see, unless in a public aquarium or the product of captive breeding.

A. chrysogaster, Mauritian Clownfish

Three Clark’s Clown impostors always have three white stripes and dark, almost brown, tail fins. (Rarely do Clark’s have dark tail fins at the size usually offered for sale.) One of these is the rarely collected A. chrysogaster, which has a white border on the soft dorsal fin and on top of the caudal fin. Juvenile Clark’s can share these white streaks on the dorsal and caudal fins, but they will grow out of them at about a year old, while A. chrysogaster retains the white highlight as adults. A yellow belly is also typical of the Mauritian Clown, which hails from two small islands to the east of Madagascar: Mauritius and RÉunion.

A. fuscocaudatus, Seychelles Clownfish

Another three-stripe Clark’s look-alike is the Seychelles Clownfish, A. fuscocaudatus, which has wide, scarf-shaped head bands and can reach 5 inches (140 millimeters) in length. Its grayish brown body, gray dorsal and tail fins, bright yellow belly, and yellow pectoral fins are typical. The margins on the white stripes of Seychelles Clowns are more blue than black. The dark rays on its tail fin most readily identify it. True to its name, this species occurs in the Seychelles and Aldabra in the western Indian Ocean.

A. tricinctus, Three-band Clownfish

A fairly localized species from the Marshall Islands, the Three-band Clownfish, A. tricinctus, has a uniformly dark tail fin and narrow head stripes. Its color varies from golden yellow to black. Adult females reach 4 inches (100 millimeters) in length.

The Saddleback Complex

This small complex of relatively rare aquarium species includes the Saddleback Clownfish (Amphiprion polymnus), which ranges from Japan to Australia, east to the Solomon Islands, and west to Sumatra. Amphiprion latezonatus, the Wide-band or Lord Howe Clownfish, is found only in a limited range of the eastern Australian coast and Lord Howe Island, while A. sebae, the true Sebae Clown, is distributed from the Arabian Peninsula to Java but is collected only infrequently. Common names can cause confusion, as the Red Saddleback Clown (A. ephippium) is not grouped here, but with the Tomato Complex.

All three fishes in the Saddleback Complex are large, reaching 4 to 5 inches (100 to 120 millimeters) in length. An aquarium of 40 gallons or more is advised for keeping any of these pairs.

These dark fishes are perhaps the clownfish group least suited to captivity. In general, clownfishes’ tanks can be kept in occupied areas of the home, but an exception must be made for the Saddleback Complex. While they are adapting to their new environment, night motions (like walking past their tank) can cause these fishes to panic and slam themselves into the sides and tops of their aquarium. Although calmer than most other clownfishes during the day and readily accepting of aquarium foods, they can still be “spooked” by a hobbyist just reaching into the tank. This produces a frenzy of destructive swimming and jumping. Do not assume that these fish have become acclimated until they have been in your tank for more than three months. After this period, there may still be episodes of panicky behavior. Even worse, they (particularly A. latezonatus) may die mysteriously two or three months after being confined. Use a fully covered top on their tanks and make sure the tank decor allows for a long, unobstructed raceway.

The Saddleback Complex fishes also suffer from collection and transportation stress and often arrive at retailers’ shops in poor condition. The highest clownfish respiration I’ve ever encountered—116 “breaths” per minute—was in an A. polymnus. A clownfish cannot sustain that rate for long. I’ve had fair success countering their stress by placing them in tanks with severely depressed specific gravity (1.012 to 1.014) for the first couple of weeks.

Once adapted (no small feat) these fishes do reasonably well and have spawned in captivity, although tank-raised adults are scarce, due to their fragility. In Italy, hatchery-raised A. sebae are more common. Selective breeding for hardiness and calmness could benefit this group, but it will take persistence and finesse.

Amphiprion polymnus, Saddleback Clownfish

The first classified clownfish species was A. polymnus, the Saddleback Clownfish, originally identified by the Swedish naturalist Carolus Linnaeus in 1758. Those were the days before scuba divers, of course, hence specimens for identification were dredged from the ocean and the relationship between the clownfishes and their host anemones would wait more than a century to be observed. Until then, the Saddleback Clownfish was just considered another small, colorful member of the damselfish family.

They can reach more than 4 inches (100 millimeters) in length. Two distinct strains, quite different in appearance, are available. Conventional Saddleback Clowns have a white head bar and a saddle-shaped midbody bar (wide at the top, missing at the bottom). The face, lower body, and pectoral fins are yellow or, occasionally, burnt orange. The upper body is black, with the black tail fin circled in white.

The black variant of A. polymnus, sold in my area as the “Black Percula,” is an attractive fish. Members are black-bodied with yellow faces, white-fringed tail fins, and bright yellow-outlined pectoral fins. They have conventional Saddleback striping on the head and tail only. The center stripe abandons the saddle shape for which the species is named.

A. latezonatus, Wide-band (Lord Howe) Clownfish and A. sebae, Sebae Clownfish

Wide-band Clownfish range in color from golden brown to black, with three white stripes. The middle bar is distinctively broad—wide enough at the bottom to extend from the pelvic fin to the anal fin. This species does best in a cooler aquarium (22 to 25 degrees C), and is not easily obtainable. The name “Sebae” is often misapplied to various members of the Clarkii Complex, but true Sebae Clownfish are far from commonplace in the aquarium trade. Sebae Clowns have two white bars, with the body stripe forming a rough S, tilting at the top toward the rear of the fish and into the dorsal fin. They also have yellow tail fins. Juveniles are yellow but turn dark brown as they mature.

Excerpted from the Clownfishes: A guide to Their Captive Care, Breeding, and Natural History ISBN 1-890087-04-1. ©T.F.H. Publications, Inc. Used with permission. Now available as an e-book exclusive for Amazon Kindle, Apple iDevices, Barnes & Noble Nook, and through other major e-book retailers.