Hammer Coral

Introduction

The hammer Coral is a very attractive and popular among the saltwater aquarium enthusiasts due to their beautiful coloration. It is a cnidarian’s large polyp coral which is also known as Euphyllia Hammer Coral, Anchor Coral, Sausage coral, Ridge coral, and Bubble honeycomb coral, etc. Its common names are derived from the appearance of its hammer, or anchor-shaped tentacles. It belongs to the family Euphylliidae under order Scleractinia of class Anthozoa. It is distributed in the waters of the northern Indian Ocean, the central Indo-Pacific, Australia, Southern Japan and East China Sea, and Papua New Guinea and the Solomon Islands with a large presence in Indonesia.

Overview

The hammer coral has unique tentacles with anchor, hammerhead or sausage-shaped tips. The tentacles move about which adds some motion to the reef aquarium. It inhabits in shallow turbid reef environments with gentle wave action where it forms large colonies that covers thousands of square yards. During feeding, the individual tentacle can extend 2 to 3 times their normal state. The color ranges from pink on pink, pink, and brown, yellowish-green, gray and a pinkish and bright green to neon green. In the wild the fleshy polyp of this coral feeds upon by many butterflyfish, triggers, puffers, angelfish, surgeonfish and rabbitfish. Some colonies of this coral can reach over 1 meter. At present it faces several threats due to water pollution and over exploitation for the aquarium trade.

Facts Sheet

Scientific name:Euphyllia ancora

Common name: Hammer coral, Anchor Coral, Sausage coral, Ridge coral, and Bubble honeycomb coral etc.

Origin:Australia, Indonesia, Solomon Islands

Care level: Moderate

Temperament: Aggressive

Placement: Bottom of the tank

Diet: Carnivore

Lighting: Moderate

Water flow: Medium

Feeding

The symbiotic algal zooxanthellae are hosted within the body of the hammer coral. The majority of the nutrition comes from the symbiotic algal zooxanthellae during the process of photosynthesis with proper lighting condition. For optimum growth, you try to give them small meaty foods, such as mysis, brine shrimp (Atemia spp.), newly chopped fish, mollusk, crustacean flesh etc. once or twice a week. To make good tank environment and for good health, you should add sufficient calcium, strontium, and other trace elements to the water.

Housing

The hammer coral is sensitive to water conditions and it can be kept in a reef aquarium with plenty of room between it and other neighboring corals. The tank should have moderate lighting with low or moderate levels of water movement. For sufficient lighting, T-5 fluorescents and metal halides do well. It is a very strong stinger and has long sweeper tentacles which can extend up to six inches in the reef aquarium and can sting any other corals or animals. It can also damage other stony coral that is placed near to it. To prevent any damage of other coral in your aquarium, you should keep a buffer zone of at least 5 or 6 inches around your coral. For successful colony and good tank environment, 20% water should be changed each month.

Propagation

The hammer coral can easily propagate in the captive condition with proper care. In the wild it takes 2 years for a colony to repopulate. It reproduces sexually by releasing an ovum and sperm through the process of gametogenesis. After fertilization, it then forms free-swimming larvae, called a planula. The planula larva settles down onto the substrate and then forms a tiny polyp which begins to excrete calcium carbonate and develops into a coral. It also reproduces asexually by producing daughter colonies at the base of the parent coral.

To propagate in captive condition, you need to choose a healthy coral. During captive propagation, coral frag is removed using an electric saw with hand gloves at least 1.5 to 2 inches away from the top. After removing coral frag from the colony, it should be attached with frag plug using underwater epoxy or cyanoacrylate gel superglue.The coral frag should be kept under ample water flow. Under optimum conditions, the frag forms a new coral within few days. Sometimes this process leads to some tissue damage and may result in bacterial infections.

Disease

Euphyllian coral is fairly hardy but sometimes it is susceptible to a few maladies such as brown jelly or protozoan infection due to poor water quality, tissue damage, a collection problem and intense lighting. To make a good tank environment, water change should be done on a regular basis. To treat, coral should be removed from the water and then brush or siphon off any visible brown jelly. The skeleton of hammer coral is also susceptible to boring green algae, which can eventually cause the demise of the polyp. Protozoan infections can also be treated with broad-spectrum antibiotics like Neomycin sulphite, Kanamycin etc.

Conclusion

The Hammer Coral is a favorite large polyp stony coral among the aquarium enthusiasts due to their brilliant and gorgeous color patterns. It has long tubular tentacles with tips that resemble the head of a hammer or an anchor which give its common name ‘hammer coral’ or ‘anchor coral’. It is available in local pet shops or online vendor with reasonable prices.

Photo: Hammer coral (Euphyllia ancora)

References Link