Small, colorful fish are always a popular choice for marine aquariums, especially reef aquariums. Add in interesting behavior and a fish with a personality, and you come up with one of the most popular family of aquarium fish: the hawkfish.
These small, grouperlike fish get their popular name from their habit of perching on or within the branches of corals and other outcroppings and then swooping down to catch prey. One of their more endearing qualities is that they are very inquisitive and unafraid to swim up to your hand while you clean the tank, or even swim right next to your facemask in larger tanks. Quite a few aquarists report that it is not unusual for their hawkfish to sit on a perch in the tank where they can watch them as they move around the room.
Hawkfish belong to the family Cirrhitidae, and there are 12 recognized genera and one questionable one (Cirrhitoidea). Within these, there are 38 species, of which five are questionable. The dorsal spines have a small membrane at the tip, which contains a single cirrus, featherlike extension (genus Paracirrhites) or a tuft of many cirri (as seen in most of the other genera.
Black-sided hawkfish. Photo by Nick Hobgood/Wikipedia
The reason hawkfish spend so much time perched is that this conserves energy. This is essential because the fish in this family do not have swim bladders. In addition, the lower pectoral fin rays are thickened, which helps to wedge them among coral branches and hold them in place during a current surge (Randall, 2005). Hawkfish have fairly large mouths compared to their body size, along with a row of small, razor-sharp teeth, which help them capture their natural dietary items, crustaceans and small fish.
Hawkfish Distribution and Natural Habitat
Hawkfish are found on coral reefs throughout the tropics, extending from the tropical Atlantic to the eastern, central, western and southern Pacific, the Indian Ocean and into the Red Sea. They are found from water as shallow as a few feet to more than 300 feet deep (Myers, 1991).
As mentioned previously, hawkfish are found primarily among stony corals, but some, such as the longnose, are found predominantly living among black corals and gorgonians, and others enjoy sponges. The flame hawkfish is an exception; it is only found in small groups in stony corals in the genera Pocillipora and Stylophora (Myers, 1991).
Hardy and Easy to Feed
Hawkfish are among the most hardy of marine aquarium fish. They rarely display signs of disease; in fact, other fish in the system will display disease symptoms before the hawkfish will (Fenner, 1998). This family of fish is easy to feed and readily accepts a wide range of foods.
Hawkfish tend to get along with most larger fish species but are not to be trusted with smaller families such as gobies. There are, however, a few caveats that I will detail a little later.
Hawkfish are not sensitive to water quality, and the normally accepted ranges for marine aquariums of ammonia, nitrate, temperature and pH are fine. Myers (1991) does mention that for one species, the flame hawkfish, the water should be well-oxygenated but offers no reasoning behind his recommendation.
Spotted hawkfish. Photo by Jens Petersen/Wikipedia
Given that this species tends to live in coral heads, such as Pocillopora meandrina, a species that is commonly found along reef crests where wave action is strong, the need for well-oxygenated water may have been surmised.
A tank that will house hawkfish does not need to be designed in any particular fashion. However, a larger tank of approximately 100 gallons or greater offers the possibility of keeping more than one hawkfish. These fish tend to be jumpers, so the tank should have a cover or hood with small external openings, or you may find your fish on the ground one morning.
Offer plenty of places to perch, such as rock outcroppings, branching corals or gorgonians. If the fish can’t find a perch suitable to its liking, they will often make do and you might find them perched on in-tank water returns or pumps, or even on window-cleaning magnets left on the upper sides of the tank.
In the wild, hawkfish feed on crustaceans of various sizes and small fish, depending on the species of hawkfish. In the home aquarium, feed them a variety of meaty foods, such as chopped prawn, crab meat, squid and frozen mysis. They will also feed readily on live blackworms, pellet diets and even flake food.
As mentioned previously, feeding them is not an issue but the foods should be varied to maximize the nutritional diversity and minimize the chances of developing fatty livers.
Hawkfish tend to be aggressive feeders, so they do well in tanks with larger fish, but may outcompete smaller fish for food. Feed food that your hawkfish will eat so that it is satiated before feeding food for the smaller fish.
Colorful species, particularly those with a lot of red, tend to lose some of their color intensity over time. This is usually due to diet and is best combated by offering a variety of foods, including items that contain color-enhancing pigments, such as astaxanthin and canthaxanthin, which are natural carotenoid pigments found in some prey items, such as crustaceans. Various flake and pellet foods will provide these pigments.
Hawkfish can be kept with most other fish species, but this can vary with the species.
Generally, any fish too large to fit into the mouth of the hawkfish should be safe (Fenner, 1998). However, some species can be particularly aggressive, and they will be noted in the species descriptions.
Some hawkfish can become territorial over time, and this can be addressed by moving around the contents of the tank to make it seem like a different environment (Fenner, 1998).
Keeping more than one species of hawkfish can be problematic; they can become aggressive toward each other. Keeping pairs is possible, provided they are a mated pair. Most species are believed to be haremic, but it is often difficult to determine sex, as there is no sexual dimorphism in color (Myers, 1991; Randall, 2005).
However, some believe there can be morphological differences in body shape between the sexes (J. Sprung, personal communication). Also, the males of haremic species are more aggressive because they usually defend a territory against invading males while maintaining a harem of females, so this may explain some of the aggression seen in aquariums when attempting to add more than one hawkfish.
When looking to establish a pair, choose two fish that differ significantly in size; in most species, the males are larger than the females (Michael, 2004). For species that are particularly aggressive, it is often best that they are the last fish added to a tank of already-established, more-peaceful species. Adding smaller, peaceful fish to a tank that already contains an aggressive hawkfish species is usually unwise; the fish will have already set up its territory and will defend it vigorously.
While it is possible to keep two hawkfish together for extended periods, especially if they are of different sizes, this does not always remain so. Hawkfish can change sex. If the smaller fish of a pair changes to a male, this might then inspire the larger male specimen to attack it in an attempt to chase it out of its territory (Michael, 2004). If you see this happen with your previously happy pair, you must remove the smaller one as quickly as possible, or it will be killed.
For the most part, hawkfish cannot be trusted around crustaceans such as shrimp, small crabs and hermit crabs. Even snails will be preyed on by the larger species. Crustaceans are particularly vulnerable after they have molted because the chemicals they release in the water during this period serve has cues for predators like hawkfish.
While hawkfish will not bother corals or giant clams, their habit of sitting on them may cause damage to more delicate corals or prevent them from fully opening. In the case of giant clams, they will eventually habituate to the fish sitting on them, but there is also danger of the fish being trapped by the clam if it closes rapidly. I have seen photographic evidence of this, and the fish was eventually let go and was unhurt. If I had not seen the photo and heard the account of the person who saw it happen, I would not have believed it.
As mentioned, most hawkfish species are believed to be haremic. This means that they live in small groups of one male and several females (Myers, 1991). However, resource limitations can result in their forming only pairs, as was shown with both flame and longnose hawkfish, a situation known as facultative monogamy (Donaldson, 1989). Therefore, reports of pairs of these fish in home aquariums are factual.
Hawkfish are protogynous hermaphrodites, beginning their mature life as females and later in life changing to males (Randall, 1996, 2005; Sadovy and Donaldson, 1995). Hawkfish are also believed to be broadcast spawners, with a male/female pair making a rapid ascent up and away from the reef and then releasing their eggs and sperm at the apex of the ascent. Although there have been reports of longnose hawkfish laying egg masses, those reports have been dismissed because it is generally accepted that all hawkfish species are pelagic spawners (Thresher, 1984).
Once fertilized, the eggs are then pelagic, and once hatched, the larvae can take up to several weeks to settle (Myers, 1991). Donaldson (1986) reports on the spawning behavior of the dwarf hawkfish in Japan, and Donaldson and Colin (1989) report on longnose hawkfish in Papua, New Guinea, if you are interested in reading more about the courtship behavior of these species.
Now that we have discussed some of the basics of hawkfish ecology and care, let’s look at some of the more popular and commonly imported species.
Spotted Hawkfish (Cirrhitichthys aprinus)
Spotted hawkfish. Photo by Charles DelBeek
The spotted hawkfish is commonly found throughout the western Pacific from southern Japan to the Great Barrier Reef, extending eastward to Tahiti and westward to the east coast of Africa. Males are larger than females, ranging from 2.3 to 3.9 inches, while females are smaller, ranging from 1.6 to 3.3 inches (Michael, 2004). They are found from 16 to 130 feet in areas rich with corals and sponges (Michael, 2004).
This species is often confused with C. falco and C. oxycephalus, but it can be distinguished from them by having three short bars below the eyes and a series of small dots on the forehead. The spots on the body are less distinct than C. oxycephalus and often merge into one another to form bands. There are at least two color forms of this species: brown and red varieties. The red is by far the more attractive.
Although a small species, spotted hawkfish can be aggressive to smaller fish and crustaceans and should not be kept with them. This is a species that can be kept in male-female pairs, and if not available as a pair, select two that are disparate in size.
Dwarf Hawkfish (Cirrhitichthys falco)
Dwarf hawkfish. Photo by Charles DelBeek
The dwarf hawkfish, as its name implies, is one of the smaller hawkfish species. Males can reach between 2 and 3 inches while female range from 1.5 to 2.3 inches (Michael, 2004). As with other species in this genus, there are multiple cirri present on the majority of the dorsal spine flaps, giving fish in this genus a rather tufted appearance.
This widespread species is found throughout the western Pacific and as far west as the Maldives, north to Japan and south to the southern Great Barrier Reef. It is found along reef slopes of 13 to 150 feet among and at the bases of corals (Myers, 1991; Randall, 2005).
This species is a great first choice for hawkfish keepers because it less aggressive and stays smaller than some of the larger species. However, it still should not be trusted around smaller, less-aggressive species, such as gobies, flasher and other smaller, less-aggressive wrasses (Michael, 2004).
Pixy Hawkfish (Cirrhitichthys oxycephalus)
Pixie hawkfish. Photo by Charles DelBeek
The pixy hawkfish is another widespread species extending from the Red Sea in the west to Panama in the east and throughout much of Micronesia and the Marquesas (Myers, 1991). It is found among areas of rich coral growth in all zones of the reef, from surge-zone depths down to 130 feet (Myers, 1991).
It is another small species, with males ranging in size from 1.8 to 2.1 inches and females from 1.4 to 2 inches, but don’t let the small size fool you. While its common name may conjure up images of delicate fairies, you may recall that Tinker Bell could be particularly aggressive at times, and so it is with this little fish. They are not to be trusted with smaller species, such as gobies, small dottybacks, grammas, pygmy angelfish and butterflyfish, dartfish and sand perches (Michael, 2004). This is definitely a fish that should be added last.
Flame Hawkfish (Neocirrhites armatus)
Flame hawkfish. Photo by Charles DelBeek
Probably no other hawkfish elicits as much passion as the flame hawkfish. Its brilliant, deep red color combined with black markings around the eyes and dorsal surface makes for a striking contrast. The degree of black can vary, especially around the eyes and on the face.
Randall (2005) reports this species reaching a maximum length of 3.5 inches with a range as far east as Pitcairn Island in the eastern Pacific, west to the Great Barrier reef and north to the Ryukyu Islands. It is a facultative, monogamous species, and some believe that the males have a larger, more-robust forehead than females. This difference in appearance has been used to successfully form pairs more often than not.
Males can range in size from 1.8 to 2.8 inches, and females range from 1.4 to 2.4 inches (Michael, 2004). This species is an obligate coral-dwelling species in the wild, where it hides within the branches of Pocillopora spp. coral, but it does quite well in captivity without them.
Flame hawkfish can be aggressive toward other, smaller fish and should be closely observed when adding new fish to a tank containing them. Unless you can get a pair or a group of one male to two or three females, one fish per tank is the usual rule. They will also go after small shrimp, snails, hermit crabs and crabs as likely targets. There is a chance they will eat small fanworms, as well.
Longnose Hawkfish (Oxycirrhites typus)
Longnose hawkfish. Photo by Charles DelBeek
Along with the flame hawkfish, this is one of the most popular species kept in aquariums. Its unusual shape, with its greatly elongated snout and crisscross of red lines on a white-to-translucent background, make it very distinct from the other species, so much so that it is the only species in its genus.
Commonly found living on black corals and large gorgonians, such as Melithaea and Muricella, this species is typically not seen till at least 80 feet and can be found as deep as 300 feet (Myers, 1991). The Steinhart Aquarium in San Francisco currently displays a pair collected at 250 feet by their rebreather deep-diving team.
Males are thought to be larger than females and can reach up to a little more than 5 inches in length. However, the size disparity between males and female is more subtle than that of other hawkfish species (Michael, 2004). They are found from the Gulf of California in the east all the way across to the Red Sea in the west, north to southern Japan and Hawaii, and south to Australia (Randall, 2005).
Longnose hawkfish can be good tankmates, but they are not to be trusted around small fish, shrimp or hermit crabs, which they will readily eat. While their forcepslike mouth may appear to be small, this is deceptive, and they can open their mouths much larger than one might suspect. This species is particularly prone to jumping, and an aquarium cover is a must. Due to the long snout, the movement of turning their heads slightly appears exaggerated, and you can get the impression that they are looking at you.
It is thought that in addition to being larger, males also have black edging on their caudal and anal fins. They form harems of one male to two or three females, with the males visiting the females on adjacent corals or meeting at a common perch, where they then ascend as a pair into the water column at dusk to release their eggs and sperm. This species has been bred in captivity, but to date, they have not been reared beyond a few days (Tanaka and Ohyama, 1991).
Arc-Eye Hawkfish (Paracirrhites arcatus)
Arc-eye hawkfish. Photo by Charles DelBeek
The arc-eye hawkfish is another popular species. It can reach a length of 5.5 inches, but this is not the norm. Adult females usually range from 1.6 to 2.7 inches long, and males can be 2 to 3.7 inches.
It has a distinct ringlet of orange, black and blue that extends out behind the eye. There are also typically three small orange bands at the base of the gill cover. There are two color morphs of this species. One has a light grayish to orangeish-brown body with a broad white to pale-pink band running along the rear part of the lateral line. The other is a dark brown without the whitish band (Randall, 1991). This species is wide ranging, being found from the east coast of Africa to the Hawaiian Islands, Japan and Australia (Myers, 1991). On the reef, this species is common down to 100 feet and often found perched on heads of Pocillopora, Acropora and Stylophora (Myers, 1991).
Arc-eye hawkfish should not be trusted around small crustaceans or fish like gobies or even small damsels. They do fine in tanks with larger fish and are best kept singly. However, when established, they might even harass larger fish when they are added (Michael, 2004).
Blackside Hawkfish (Paracirrhites forsteri)
The blackside hawkfish is named after a father and son team of naturalists, the Forsters, who accompanied Captain Cook on his second voyage to the Pacific from 1772 to 1775 (Hoover, 1993). This is another widespread species ranging from the Red Sea to the Hawaiian, Line and Marquesan and Ducie islands, and north to Japan (Myers, 1991). Like the arc-eye hawkfish, this species is found perched among Pocillopora eydouxi, Acropora and Millepora fire coral along outer reef slopes, down to at least 100 feet (Myers, 1991).
This larger species is an aggressive fish-eater and is best kept with larger fish species. Michael (2004) states that it can reach lengths up to 7 inches in the males and 5.7 inches in the females, but Randall (2005) lists the largest recorded size at 8.9 inches.
This fish should also not be trusted among crustaceans and snails, and is best suited to a larger system with larger tankmates. One of the reasons the blackside hawkfish is often encountered for sale is that juveniles are quite colorful, being all white along the dorsal surface with a brown band extending along the body above the white and then a yellow or orange band extending along the dorsal surface above the brown.
Once the fish becomes an adult, this pattern disappears and brown or red spots appear on the head, and the rest of the body can turn a chocolate, olive or maroon color, becoming yellow toward the rear of the body (Myers, 1991). So, beware of the juvenile, as it will not retain this color as it grows and will become much more aggressive.
These are just a few of the species that occur in this fascinating group of fish. For more information and descriptions of the other species seek out the references listed, particularly Scott Michael’s Reef Fishes, volume 2, dealing with this family of fish, which is the most complete aquarium reference available and enjoy keeping the raptors of the reef!
Charles Delbeek has cared for marine organisms in closed systems for more than 43 years and has lectured at more than 80 aquarium-related conferences and meetings, He has chaired several professional conference sessions and published more than 130 articles in the popular aquarium and scientific literature, including three popular aquarium books with Julian Sprung, The Reef Aquarium series, considered by many to be the definitive works in the field. Charles provides consulting services through his company, JCD Consulting (jcdaquariumdesign.com), to public and private aquarium projects around the world.