Blue-spotted Grouper

Those beautiful, bright, blue spots on the Peacock Hind will be the last thing most fish or eels see!  Yet this behemoth has a sweet side, eventually eating out of it’s owners hands!

The Peacock Hind is a large, deep bodied fish, covered with small, bright, blue spots edged in black.  The front of the body can be a solid greenish brown, maroon or brown on the front half of the body, with those colors forming 5 to 6 vertical bars at the back half of the body, over a whitish or yellowish background.  There is a small area of the chest that is pale, located in front of the pectoral fin, and this area is absent of spots.  Their fins each have a wide, bright blue margin.  The tailfin is rounded, and their pelvic fins are short.  Peacock Hinds have small eyes that are mounted near the top of the head, which is typical for predatorial fish.  They can reach 17” (44 cm) and groupers are known to live from 9 to 37 in the wild, possibly longer in captivity with proper care.   They are a great beginner’s fish with the correct tank size.

Peacock Hinds were introduced in the 1950‘s to the Hawaiian Islands as a possible food source, although today, most carry ciguatera poisoning (causes neurological disease) and they are off the menu in this area.  The Cephalopholis genus, commonly referred to as “Hinds,” contain smaller species of groupers which are more appropriate for home aquariums.  They range in size from around 9” to 22.5,” and at least 8 of these species range from 9 to 11.8.”  The Peacock Hind, sometimes referred to as the Bluespotted Grouper, can be confused with the Bluespotted Hind, mainly due to the fact that both have bright blue spots.  Upon closer examination, the Peacock Hind has a wide, bright, blue edging on the fins.  The Starry Hind (C. polyspila) is also similar, yet has smaller and more numerous white or light blue spots, has spots on the chest area, and does not have the blue margins on the fins.  The coolest behavior observed by the Peacock Hind is how it will follow octopuses and Gray Morays who are foraging for food.  If one of them flushes out a prey fish, the Peacock Hind will get a free dinner!  Peacock Hinds will also hide within large schools of Parrotfish which enables them to get very close to their pray without being seen.  When the Parrotfish descend to feed on algae, the Peacock Hind will pop up and rush out to feed on those inattentive fish and crustaceans!  

The first challenge that prevents an aquarist from keeping this fish is their tank size, since a very large tank is necessary for their size.  The second challenge would be filtration, since groupers are big eaters, and produce copious amounts of waste, requiring a good quality oversized skimmer and two canister filters like Eheim or Fluval, cleaned twice as often as the directions suggest to keep them working effectively.  The third and final challenge are the tank mates that can be kept with this large fish.  A slender fish and even eels that are the same length as your Peacock Hind will be consumed.  How, you ask?  As the Peacock Grouper ingests a long and narrow tank mate, the prey fish/eel coils up in it’s belly.  Think….spaghetti!  Even the Gray Moray Eel, which the Peacock Hind hunts with in the wild can become dinner if they are not careful!           

The Peacock Hind can be kept with other hinds and groupers, but only one Peacock Hind per tank.  They will eat any fish they can get in their mouths.  At times they will try to eat a fish they can’t quite get down their throat, and the aquarist will have to lend a hand to extract the unfortunate tank mate.  Other tank mates are safest if they are deep bodied and of similar size or larger.  Large angelfish that are at least 14 to 15” or more as adults are good choices.   Soapfish, larger triggerfish, large butterflyfish, pufferfish, adult Lionfish or other similarly sized and similarly aggressive tank mates are okay.  If attempting to keep with cleaner shrimp from the Lysmata or Stenopus genus, add them first.  Groupers may still possibly eat these shrimp if they are not well fed.  Peacock Hinds need to be the last fish added to an aggressive community tank.  

The aquarium should be at least 180 gallons, though 250 gallons is probably more reasonable.  The configuration of the tank can be shallow or deep.  Provide at least two areas in which the Peacock Hind can hide at night, more if there are other groupers, since each will defend their hiding places.  Well arranged live rock work will help them to adjust and will help provide the biological filtration (along with a strong skimmer) that is needed for these large fish.  Water movement and light are not as important as offering them a varied diet of crustacean flesh when young, and larger diets of fish flesh when they are adults.  Feed them several times a day as very small juveniles, then once a day as adolescents, and only 2 to 3 times a week to satiety as adults.  They prefer to hide under ledges and in caves, but will sit at the bottom of the tank near their hideout as they become more comfortable.  

• For more information on keeping this fish see: Guide to a Happy, Healthy Marine Aquarium

Habitat: Distribution / Background

The Peacock Hind, Cephalopholis argus, was first described by Schneider in 1801.  The common names this fish are known by are Peacock Grouper, Peacock Hind, Bluespotted Grouper, Blue Spot Grouper, Argus Grouper, Black Rock-Cod, Grouper, Peacock Cod, Peacock Coral Cod, Peacock Rock Cod, Seabass,  and World-wide Peacock-Rockcod.  The names describe the coloring or species name.  The name World-wide Peacock Rockcod indicates the far flung distribution of this fish.  Though the Australians refer to them as “cods” or “rock-cods,” they have no relation to cold water cods that are commonly eaten from the Gadidae family that we find in our local grocery stores.  So far, there are 22 species in the Cephalopholis genus, and this particular genus is referred to as the “Hinds” by some.

Distribution – Habitat:

The Peacock Hind was originally found in the Indo-Pacific from the Red Sea to Durban, South Africa then east to the French Polynesia and Pitcairn Island Groups, north to the Ryukyu and Ogasawara Islands then sound to the northern parts of Australia and Lord Howe Islands.  As of the 1950‘s, they are found around the Hawaiian Islands.  These groupers prefer shallow water that is clear, within exposed reef crests and reef faces with plenty of coral growth.  They are also found in tide pools and prefer reef zones from depths of 3 to 33 feet (1 to 10 m), yet can be found at depths down to 131 feet (40 m).  Juveniles are most often found in shallow waters hiding deep within dense coral thickets.  

In the Red Sea, Peacock Hinds feed in the early mornings and late afternoons, whereas, in Madagascar, they feed at night.  Juveniles typically eat more crustaceans than adults, who prefer fish.  Other creatures they have been known to consume, according to the region are Dusky Tangs (Acanthurus nigrofuscus), Convict Tangs (A. triostegus), Purple Tangs (Zebrasoma Xanthurum), Sailfin Tangs (Z. desjardinii), Orange Bristletooth Tangs (Ctenochaetus striatus), Iridescent Cardinal Fish (Apogon kallopterus), Orange Lined Triggerfish (Balistapus undulatus), Red Speckled Blennies (Cirripectes variolosus), Arc Eye Hawkfish (Paracirrhites arcatus), Six-line Wrasses (Pseudocheilinus hexataenia),  Pterocaesio Tilefish, Hawaiian Squirrelfish (Sargocentron xantherythrus), Belted Wrasses (Stethojulis balteata), Lyretail Anthias (Pseudanthias squamipinnis), Kluzinger’s Wrasse (Thalassoma klunzingeri), Sweepers, Blue Green Chromis (Chromis viridis),  Pseudogrammas, Mackerels, Gobies, Gray Morays (Siderea grisea), Damselfish, crabs, decapod shrimp, mantis shrimp, and spiny lobsters.  Basically, they will eat whatever they can fit in their mouths!  Peacock Hinds can eat fish as long as they are if they are narrow.  Those long prey fish/eels will coil up in the stomach of the Peacock Hind until digested.  

As adults, Peacock Hinds are found alone, or in harems that consist of one male with as many as six females.  These males occupy some of the largest territories compared to other groupers.  The territory size is determined by the number of females and their territories.  For example, a male with 2 females would have a smaller territory than a male with six females.  Males will viciously defend their territory.  They will first perform lateral displays and open their huge mouths to intimidate their opponent.  Next, they will start to chase and nip until the other fish is driven out of their territory.  If a rival grouper wants to fight, both fish will face each other and lock jaws for up to 5 minutes!  The loser, typically the weaker fish, will then swim off, leaving the harem of females for the victor. 

The Peacock Hind is listed as Least Concerned on the IUCN Red List for Endangered Species, with a stable population trend. 

Similar Species:

• Bluespotted Hind (Cephalopholis cyanostigma) – This fish lacks the wide, bright blue margins on the fins like the Peacock Hind.  The Bluespotted Hind is not a solid color near the front half of the fish, but has mottling and irregular pale bars.  
  
• Starry Hind (Cephalopholis polyspila) – This fish has smaller and more numerous white or light blue spots, has spots on the chest area and does not have the blue margins on the fins.
• Scientific Name: Cephalopholis argus
• Social Grouping: Solitary – Although they can be found in harems in the wild, only one Peacock Hind per aquarium.
• IUCN Red List: LC – Least Concern – Least Concerned

Description

Peacock Hinds are easy to care for as long as their needs are met.  Provide them with a tank that is at least 180 gallons and several hiding places within the live rock.  Some websites suggest the tank needs to be 250 gallons, and this is not out of the question, especially if you are considering more than one grouper, since these large fish produce a lot of waste and higher water volume will help keep up the water quality.  A 15” grouper is a much bigger fish and needs more water volume than a 15” wrasse.   Once full grown, they will require at least 2 hiding places, which they will defend.  The tank should have a heavy duty skimmer due to the large amount of waste this fish produces.  Although some individuals may need live foods to elicit a feeding response, aquarists can easily switch them over to prepared foods.  Feeding groupers fresh water fish will cause health issues if continued for too long.  Do not house them with other Peacock Hinds, although they will be fine with other groupers as long as the tank is large enough.

• Size of fish – inches: 17.0 inches (43.18 cm) – 17” (44 cm)
• Lifespan: 37 years – Groupers are known to live from 9 to 37 in the wild, possibly longer in captivity with proper care.

Fish Keeping Difficulty

Peacock Hinds are easy to care for as long as their needs are met.  Provide them with a tank that is at least 180 gallons and several hiding places within the live rock.  Some websites suggest the tank needs to be 250 gallons, and this is not out of the question, since these large fish produce a lot of waste and higher water volume will help keep up the water quality.  A 15” grouper is a much bigger fish and needs more water volume than a 15” wrasse.   Once full grown, they will require at least 2 hiding places, which they will defend.  The tank should have a heavy duty skimmer due to the large amount of waste this fish produces.  Although some individuals may need live foods to elicit a feeding response, aquarists can easily switch them over to prepared foods.  Feeding groupers fresh water fish will cause health issues if continued for too long.  Do not house them with other Peacock Hinds, although they will be fine with other groupers as long as the tank is large enough.

• Aquarium Hardiness: Very Hardy
• Aquarist Experience Level: Beginner – Aquarist needs a tank that is 180 to 250 gallons.

Foods and Feeding

The Peacock Hind is a carnivore.  As juveniles they will even eat flake food.  If an individual will not eat, offer feeder fish or ghost shrimp.  Once they are eating, quickly switch over to prepared foods such as freeze dried or frozen krill, mysid shrimp and pellets for carnivores.  Also offer a varied diet of raw crustacean and fish flesh which can be obtained from the grocery store.  Feed very small juveniles several times a day, average sized juveniles twice a day, adolescents once a day and eventually feed adults 2 to 3 times a week until full.  Higher temperatures will make for a hungrier grouper.

• Diet Type: Carnivore
• Flake Food: Yes – Will take flake as small juveniles.
• Tablet / Pellet: Occasionally – Sinking pellets for carnivores.
• Live foods (fishes, shrimps, worms): Some of Diet – Live ghost shrimp or feeder shrimp to get a new grouper to start feeding or condition for breeding.
• Meaty Food: All of Diet – Offer a varied diet of different crustacean and fish flesh.
• Feeding Frequency: Several feedings per day – Juveniles several times a day, adolescents once a day and adults 2 to 3 times a week until full.

Aquarium Care

Groupers are hardy and fairly easy to keep, although they do need good filtration.  Live rock and a strong skimmer are a start.  Two good canister filters like Eheim that can be cleaned regularly, not every 3 or 4 months but bi-weekly to monthly to stay effective. They do well when provided good water conditions and a well-maintained tank. Guidelines for water changes with different types and sizes of aquariums are:

• Fish only tanks:

• • 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:

• • Large Tanks 100 gallons and over, once water is aged and stable can be changed 10% bi-weekly to 20% monthly, depending on bioload.

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

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

• Water Changes: Bi-weekly – Bi-weekly

Aquarium Setup

In a 180 gallon tank (681 liters), arrange live rock, forming several places for the Peacock Hind to hide, especially if the fish is a juvenile.  As the fish grows, resize their hiding places, and as an adult, provide at least two places for them to hide.  Each grouper in the tank will need 2 places to hide to help tone down aggression.  Also, arrange live rock so the two groupers cannot see each other.  The Peacock Hind is not picky about substrate or lighting, and the area they hang out in during the day should not have swift water movement, since they prefer calmer waters.  Keep the water at a stable temperature, which can be 72˚F to 81˚F (22˚ to 27˚C) .  Normal seawater salinity around 1.023 and normal pH between 8.0 to 8.4 is preferred.  Groupers have spawned in captivity in very large outdoor saltwater ponds.  They may be induced to spawn indoors if they are conditioned with more feedings, then the temperature is raised 2˚F, and there is a longer daylight period.  Of course, the tank would probably need to be hundreds of gallons.  Peacock Hinds prefer the bottom of the tank near their hideout.

• Minimum Tank Size: 180 gal (681 L) – 180 gallons (681 liters), though some websites suggest 250 gallon tanks.

• Suitable for Nano Tank: No
• Live Rock Requirement: Typical Plus Hiding Places
• Substrate Type: Any
• Lighting Needs: Any
• Temperature: 72.0 to 81.0° F (22.2 to 27.2&deg C) – 72˚ F (22˚ C) 81˚ F (27˚ C)
• Breeding Temperature: 0.0° F – Raise temperature 2˚F and feed heavily to induce spawning.
• Specific gravity: 1.023-1.025 SG – 1.023 1.025
• Range ph: 8.0-8.4 – 8.0 8.4
• Brackish: No
• Water Movement: Any
• Water Region: Bottom

Social Behaviors

Peacock Hinds, although found in harems in the wild, are best kept singly in a captive environment.  In very large 500 to 1000 gallon systems, outside saltwater ponds or public aquariums, a few females can be kept with a male.  Other groupers can be kept with the Peacock Hind, as long as they are a different coloring and there are 2 places to hide for each grouper.  With more than one grouper, the aquarium should be 250 gallons or more since they are very territorial. Also, arrange the live rock to provide barriers where their vision of each other is blocked from their normal hangout.

Most other fish will be eaten.  Long thin fish or even eels that are the same 17” length as the Peacock Hind will be easily consumed, since the prey fish coils up in the stomach of the grouper!   Even larger wrasses are usually consumed due to their more narrow bodies.  Keep Peacock Hinds with fish of similar size if they are not as deep bodied, such as tangs and triggerfish who should be at least 13” long and fish who are deep bodied like butterflyfish and angelfish who are at least 7” long.  Full grown large lionfish, soapfish, large angelfish, large butterflyfish, large adult tangs and triggerfish are usually ignored.  The only time the Peacock Hind becomes a threat, is if it is full grown and these other fish are not, and they fit in their mouth!  Keeping your grouper well fed will keep them from attempting to eat other larger fish.  It has been noted that a zealous grouper may attempt to eat a larger fish if it is very hungry, causing the fish to be stuck in the mouth of the grouper, which will need assistance from the aquarist.  Add the Peacock Hind as the last fish into an aggressive reef or fish only tank.

Peacock Hinds will not bother corals, and juveniles will hide within their branches.  Due to their size, they may knock a coral over, so secure any corals firmly to the rock.  If the coral needs very clean water, you may not want to buy it, since these large fish foul up the water rather quickly.  Figure out what kind of water quality you can maintain and only buy corals that are not picky.

Starfish are safe, but snails, shrimp, and crabs will be eaten.  If you want to keep the cleaner shrimp that are often found cleaning the grouper, such as the Lysmata species or the Stenopus species, add the shrimp first and make sure the fish is well fed.  A hungry Peacock Hind may eat the shrimp! 

• Venomous: No
• Temperament: Large Aggressive – Predatory
• Compatible with:
  • Same species – conspecifics: No – They are too aggressive and have larger territories than most groupers.
  • Peaceful fish (gobies, dartfish, assessors, fairy wrasses): Threat
  • Semi-Aggressive (anthias, clownfish, dwarf angels): Threat
  • Threat
  • Large Semi-Aggressive (tangs, large angels, large wrasses): Monitor – Only tangs and triggerfish should be 13,” and large angelfish and butterfly fish should be 7″ No wrasses since they are narrow and will be consumed.
  • Large Aggressive, Predatory (lionfish, groupers, soapfish): Safe
  • Threat
  • Anemones: Monitor – Water quality must be kept up to keep these creatures healthy.
  • Mushroom Anemones – Corallimorphs: Monitor – Water quality must be kept up to keep these creatures healthy.
  • LPS corals: Monitor – Water quality must be kept up to keep these creatures healthy.
  • SPS corals: Threat – W Water quality must be excellent for these corals.
  • Gorgonians, Sea Fans: Monitor – Water quality must be kept up to keep these creatures healthy.
  • Leather Corals: Monitor – Water quality should be monitored.
  • Soft Corals (xenias, tree corals): Monitor – Water quality must be kept up to keep these creatures healthy.
  • Star Polyps, Organ Pipe Coral: Monitor – Water quality should be monitored.
  • Zoanthids – Button Polyps, Sea Mats: Monitor – Water quality should be monitored.
  • Sponges, Tunicates: Monitor – Water quality should be monitored.
  • Shrimps, Crabs, Snails: Threat – Lysmata and stenopus cleaner shrimp may be added first, but a hungry Peacock hind will eat them.
  • Starfish: Safe
  • Feather Dusters, Bristle Worms, Flatworms: Safe
  • Clams, Scallops, Oysters: Monitor – Water quality must be kept up to keep these creatures healthy.
  • Copepods, Amphipods, Mini Brittle Stars: Safe

Sexual differences

Males are 30 to 40% larger than females.

Breeding / Reproduction

The Peacock Hinds are born female and some become males.  This orientation is called protogynous hermaphrodites.  Unlike clownfish, hawkfish and many others, many females do not change to male just because the alpha male of the group dies or leaves.  Age, not size determines when sex change occurs.  They are found in harems of one male and up to six females, with the male’s territory encompassing all the territories of the females.  Peacock Hinds have a much larger territory than many other groupers, which on average, is over 16,000 square feet!  When spawning, the male and four or five females will darken the coloring of their bodies, and a white keyhole-shaped mark will appear on both sides of the body. This starts at dusk, with a peak in spawning happening at the new or full moon.  Males will spawn with each of the four or five females in the same night, with both releasing their gametes into the water column.  The eggs are spherical and can number from several thousand to over a million eggs depending on the size of the female.

Groupers have been known to spawn in captivity, although there is not much information as to whether they are being purposely aqua-cultured. 

• Ease of Breeding: Moderate

Fish Diseases

Typically groupers are extremely hardy, but do tend to come in with multiple parasites.  A culture was done on wild-caught groupers and there were 11 to 16 different species of parasites found on their bodies, including nematodes and cryptocaryon.  Quarantining a grouper is absolutely necessary.  Happily, the grouper will respond to treatments for any parasites they are carrying.   

The most easily cured parasite 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.  Then there is Brooklynella, which kills within 30 hours, however, an even nastier killer is Uronema, which will kill fish overnight!   Uronema is often contracted when the aquarist doesn’t lower their salinity to the proper level of 1.009.  The Uronema parasite thrives in mid-level brackish water salinity, which is a specific gravity of around 1.013 to 1.020.  Treat for any illness at a normal salinity with a specific gravity of about 1.023 if the fish cannot handle low salinity, otherwise, lower the salinity to exactly 1.009, no less, no more.  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.   

Anything you add to your tank from another system that has not been properly cleaned or quarantined, including live rock, corals, equipment and fish can introduce diseases.  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

Peacock Hinds are sometimes available online with lower-priced specimens from Indonesia and much higher-priced specimens from Hawaii, Sri Lanka and Sumatra.
 

Featured Image Credit: Bluespotted grouper (Cephalopholis cyanostigma) (Image Credit: Rickard Zerpe, Wikimedia Commons CC BY-SA 2.0 Generic)