Picture of a Hammer Coral, Euphyllia fimbriata
Euphyllia fimbriata

The Hammer Coral has a very beautiful form and color, and it likes to sway in the currents!

The attractive Hammer Coral Euphyllia fimbriata is a reef keepers favorite large polyp stony (LPS) coral. It is a Euphyllia spp. that is not found around Australia. Yet it does resemble its close relative, the Anchor coral Euphyllia ancora. At times the Hammer Coral is inaccurately called the Anchor coral, or even the Frogspawn Coral E. divisa, but with a close look, you can correctly identify it.

The Hammer Coral and the Anchor Coral are very similar except the Hammer coral polyps have hammer or “T” shaped tips. The Anchor corals lack the “T” shape, rather they have semi-circular or sausage shaped tips. Though the Hammer Coral has a straighter and flatter tip, there can be curvature in the tip. There are also very nice branching anchor corals in this genus such as Euphyllia parancora.

The identification of the E. fimbriata is determined more so by the shape of the polyp tip than their delicate skeletal structure. Both it and the Anchor Coral come in colors of green and brown, with green or cream tips. This is yet another variation of a beautiful genus of LPS that is moderately easy to keep and a great addition to any display!

The Hammer Coral can be easy to moderate to care for. Like others of its genus, it will be the first to warn you that the water quality in the tank is less than acceptable. Providing it with sufficient lighting, a moderate but turbid water flow, and the availability of passing food will contribute to their success.

The E. fimbriata has been propagated in captivity. These corals are not hermatypic, which means they do not contribute to reef structures. Yet in the wild it takes 2 years for a colony to repopulate, and there is concern about over collecting these corals. In some countries they have been outlawed for collection. Propagating these corals is very important in preserving the wild colonies.

Hammer Coral, Euphyllia fimbriata

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Green Branching Hammer Colony, Teal Purple LPS Corals For Aquariums

As you can see in this video, this Hammer Coral has the classic “T” shape for it’s tentacle tips. Unlike the Anchor Coral, which has very curved, even scroll looking or bean shaped tips, the Hammer Coral, E. fimbriata has a very straight or slightly curved tip that looks quite different. These corals should be put in a minimum of 50 gallons as a small juvenile or frag, yet it can grow to 3 feet, so make sure you frag it as it grows or “we’re gonna need a bigger tank.”

Scientific name

Family: Euphyllidae
Species: Euphyllia fimbriata

The family Euphyllidae, “… is a very large family of zooxanthellate scleractinans, that were previously grouped in the family Caryophylliidae (Mather, 1994). It includes such genera as Euphyllia, Catalyphyllia, Nemenzophyllia, Plerogyra, and Physogyra.” Source: Tropical Marine Biology II, Classification of Scleractinian (Stony) Corals, by Pierre Madl, University of Vienna, 2001, Revised in Nov. 2002

Distribution / Background

Euphyllia Coral Information: The Hammer Coral Euphyllia fimbriata was described by Spengler in 1799. Other names this coral is known for, though inaccurately, are Anchor Coral and Frogspawn Coral.

Where Euphyllia Corals Are Found: E. fimbriata are found in the Western Pacific in the Philippines.

Euphyllia Coral Habitat: The E. fimbriata live in colonies in waters that are turbid, yet gentle. They are found at depths down to 131 feet (40 m) and enjoy indirect bright light. They have stinging cells to help capture small prey and to defend themselves against predators.


The E. fimbriata is not on the IUCN Red List of Endangered Species.


What do Euphyllia Corals look like: The identification of the Hammer Coral E. fimbriata is determined more so by the shape of the polyp and not necessarily their delicate skeletal structure. They form large colonies with corallite walls forming on the outer edges with the polyps having the ability to completely retract into the skeleton. Polyps extend during the day and only partially at night.

The tentacles of the Hammer Coral have hammer or “T” shaped tips. Though it has a straighter and flatter tip than its cousin the Anchor Coral, whose tips are more “C” shaped or sausage shaped, there can be curvature in the tip. The colors of the tentacles can be brown or tan with green or cream tips. When feeding, the individual tentacles can elongate 2 to 3 times their normal state. Some colonies can reach over 3 feet (1 m). Lifespan is unknown.

Difficulty of Care

Euphyllia Coral Care: The E. fimbriata can be moderate to easy to care for. Provide sufficient lighting and good turbid water flow, that is neither too strong or too weak. The availability of passing food will also contribute to their success. Using trial and error, by placing coral specimens in different areas of the tank, will eventually result in locating a favorite spot. This will be evident by full polyp expansion and feeding.

Due to collection procedures, they are often broken from parent colonies in the wild. A specimen may have soft tissue damage, especially if the skeleton has splintered into the fleshy polyp area. When purchasing your coral, make sure it has been in the store for a week or so and doing well before bringing it home. This will help you avoid a potentially sick coral, since they may take a few days after shipping to show ailments.

Foods / Feeding

Euphyllia Coral Feeding: The Euphyllia corals, like other large polyp stony (LPS) corals, have developed several feeding strategies. Through a symbiotic relationship with a marine algae, known as zooxanthellae, they receive many of their nutrients. They also capture planktonic organisms, food particles from the water column, and can absorb dissolved organic matter.

In captivity, mysis, krill, brine shrimp and other smaller items can be fed. These corals can eat surprisingly much larger chunks of food as well. Chop up or dice whole fish or shrimp and feed the entire organism to the coral. Since different parts of the animal have varying nutritional qualities, this practice of feeding your Euphyllia in such a way will yield good results. These corals are hungry all the time, so feeding as needed with various foods is helpful.

Aquarium Care

Typical water changes of 20% a month, 10% biweekly, or 5% weekly are needed. It has been noted that 5% weekly water changes replenish many of the needed additives and it is ultimately cheaper than purchasing additives for the water. With higher concentrations of coral with calcareous skeletons though, there may be a need put in additional additives to maintain proper levels for good growth.

The following water supplements are suggested for Euphyllia species:

  • Calcium: 400 to 450 ppm. If a large poly stony (LPS) coral does not have enough calcium, it will not grow. (Seachem makes a calcium additive that states 385 as sufficient)
  • Alkalinity: 3.2 TO 4.8 MEQ/L (8 to 11 dKh, 10 is recommended)
  • Phosphates: 0, zero. Phosphates are the worst of all and all corals hate them.
  • Magnesium: 1200 – 1350. Magnesium makes calcium available, so if your calcium is low, check your magnesium levels before adding any more calcium.
  • Strontium: 8 – 10

Aquarium Parameters

A well-feed live rock/reef environment is what is needed for your Hammer Coral, along with some fish for organic matter production. A mature tank is recommended.

Quick Reference Chart
Lighting:Prefers Low Lighting LevelsPrefers Medium Lighting LevelsPrefers High Lighting Levels
Water Flow:Prefers Low Water Flow LevelsPrefers Medium Water Flow LevelsPrefers High Water Flow Levels
Temperament:Peaceful TemperamentSemi-Aggressive TemperamentAggressive Temperament

Be sure to have proper water movement. Water flow that is too strong can cause the polyps to not extend properly thus inhabiting their ability to capture food. Provide sufficient lighting, they enjoy indirect bright light. Do not place directly under metal halides or its polyps can be damaged, which can lead to rapid tissue necrosis or RTN. Make sure that no other corals can come in contact with your Euphyllia. This coral can be aggressive, especially when hungry, then their sweeper tentacles can reach over 10″ (25 cm). Feeding them regularly will help alleviate this problem.

  • Minimum Tank Size / Length:50 gallons (190 L) or larger
  • Marine Lighting: Moderate to strong, yet diffused light, but no direct metal halides.
  • Temperature: 74° – 83° F (23° – 28° C)
  • Salinity / Specific Gravity: 1.023 – 1.025
  • Water Movement: Moderate / turbulent.
  • Water Region: All areas of the aquarium, depending on light and water movement.

Compatibility and Social Behaviors

Euphyllia corals can be aggressive if touching other corals and should be positioned away from all other corals. The Hammer Coral is peaceful to its own genus, but will attack other genera within its family. The E. fimbriata tend to be sensitive to aquariums that have large collections of soft corals, specifically, some Sinularia species. When hungry, their sweeper tentacles can reach over 10″ (25 cm) in large colonies, which poses a threat to nearby corals due to their strong sting. Feeding them regularly will help alleviate this problem.

Sex – Sexual differences


Breeding and Reproduction

The large polyp stony (LPS) corals are male and female and can reproduce both sexually and asexually. In the wild they reproduce sexually by releasing eggs and sperm at the same time, resulting in a fertilized egg which then forms into a free-swimming planula larva.Eventually the planula larvae settles onto the substrate, becoming plankters. This then forms a tiny polyp which begins to excrete calcium carbonate and develops into a coral. Planula larvae are extremely vulnerable to predation, and very few survive.

Euphyllia genus reproduce asexually as well. In captivity, the E. fimbriata will bud off small groups of polyps with little skeletons attached. They will also pinch off their own tentacles, which then floats off, and being sticky, will reattach and start a new colony.

To propagate you first you need to choose a healthy coral that is not showing any signs of distress. Propagation should be done with an electric saw at least 1 1/2″ to 2″ away from the top. Do not use a bone crusher or scissors, since they will splinter the skeleton and harm the polyp. Glue the frag to a plug or rock. You can use the 2-part epoxy or underwater putties.The slime that the coral will exude should not come in contact with any other corals and gloves are suggested. Give the frag ample water flow.

Potential Problems

The Euphyllia spp. are fairly hardy, but are susceptible to a few maladies. The E. fimbriata is susceptible to brown jelly or protozoan infections, collection problems, and intense lighting.

  • Brown Jelly
    Brown jelly or protozoan infections can infect the rest of the colony if not treated. This brown jelly looks exactly like it sounds, and can be caused by poor water quality and/or tissue damage. To treat, remove the coral to a container with water from the main display, then brush or siphon off any visible brown jelly. Give the coral a freshwater dip in water with the same pH and temperature as the main tank for several minutes to kill a lot of the microorganisms.
    Use an antibiotic paste on the infect areas and/or a Lugol’s dip. Cyanobacteria and brown jelly infections can be treated with Neomycin sulphite, Kanamycin and other broad-spectrum antibiotics. The pill can be pulverized into a fine powder, mixed with sea water to make a paste, and then applied to the wound, or affected site of the coral with a simple artists brush.
    Try to treat the coral with the least stressful method first. Place in a quarantine tank until coral recovers.
  • Metal Halides
    Do not place directly under Metal Halide, or the E. fimbriata’s polyps can be damaged and can lead to rapid tissue necrosis or RTN.
  • New Specimens
    Collections from the wild may have soft tissue damage, especially if the skeleton has splintered into the fleshy polyp area. When purchasing your coral, make sure it has been in the store for a week or so, since they may take a few days after shipping to show ailments.


Euphyllia Corals for Sale: The Hammer Coral E. fimbriata is very easy to find at pet shops and on line. Online they can run about $39.00 USD or more depending on size and/or color.


 Hammer Coral (Euphyllia ancora) (Image Credit: harum.koh, Wikimedia Commons CC BY-SA 2.0 Generic)