Live coral

Types of live corals

Live coral is a marine invertebrate with a hard exoskeleton. It forms the foundation of coral reefs and is classified into two main types: hard and soft corals.

• Hard corals

  Also called stony corals, hard corals are responsible for building reefs. They have a calcium carbonate skeleton, which is deposited within their tissue. The skeletons form the structural framework of coral reefs. Hard corals are mainly classified into:

  • Branching corals: Corals like Acropora and Madrepores have a branching structure that looks like trees or shrubs. They provide a large surface area for other marine animals to live in and help the reef grow vertically.
  • Encrusting corals: These spread across the reef base and cover rocks and other corals. They have a flat, crust-like appearance and include corals like Porites.
  • Columnar or massive corals: Corals like Orbicella have rounded mounds or ball-like structures. They are thick and provide strong reef foundations.
  • Plate corals: These look like horizontal slabs or dishes and include coral genera such as Acropora and Agaricia.
  • Cup or Stalked corals: Corals like Montastraea have a tubular or cup-like structure, and they can be grouped or solitary.

• Soft Corals

  As their name suggests, soft corals do not have a hard skeleton. Instead, they have a flexible internal structure called a gorgonin. They are important for reef biodiversity and provide habitat and shelter. Soft corals are mainly classified into:

  • Gorgonians: Also known as sea fans and sea whips, they have a branching structure and a skeleton made of gorgonin. Examples include Gorgonia and Pseudopterogorgia.
  • Leather corals: They have a thick, fleshy body wall with a gorgonin and calcium carbonate mixture. They can be solitary or colonial. Examples include Sarcophyton and Lobophytum.
  • Black corals: These have a chitinous and protein-based skeleton. They can be solitary or colonial and include Antipathes.
  • Sea pens: They have a feathery appearance and a calcium carbonate and chitin-based internal skeleton. They can be solitary or colonial and include Pennatula.

Design of live corals

• Brain Coral (Meandrina spp.)

  Live brain corals are large, round, or dome-shaped. They have deep ridges and valleys, like a brain. They come in many colors, including brown, yellow, and green. Their surface is smooth or bumpy.

• Elkhorn Coral (Acropora palmata)

  This coral looks like the antlers of an elk or deer. It has thick branches that fork outward. The branches can be light brown, yellow, or gray. The tips of the branches are usually rounded and smooth.

• Staghorn Coral (Acropora cervicornis)

  Staghorn coral has many straight, branching structures. It looks like the horns of a stag animal. The branches are light brown or tan. They are usually smooth and can be quite delicate.

• Table Coral (Acropora spp.)

  Table coral has broad, flat, horizontal branches that spread out. They look like a round table. The edges may be irregular, and the surface can be smooth or bumpy. They come in various colors, including blue, green, and purple.

• Brain Coral (Diploria spp.)

  These corals have large, round, dome-shaped structures with complex ridges and grooves. They appear gray, brown, or greenish. Their surface is smooth or bumpy. They can grow several feet across and provide a solid base for other corals to build upon.

• Foliose Coral (Montipora spp.)

  These corals look like leaves or layers. They have thin, flat, overlapping plates or sheets. The plates can be smooth or textured and come in many colors, including red, orange, and green. Foliose corals are flexible and can bend with water movement.

Usage scenarios of live coral

Live corals are essential for maintaining the health and diversity of marine ecosystems. Their usage scenarios include:

• Coral reefs provide marine biodiversity. They are home to over one million species, including fish, crustaceans, mollusks, sea turtles, and marine mammals. Live corals are vital for fisheries. They support commercial and recreational fishing industries, providing species like snapper, grouper, lobster, and shellfish.
• Coral reefs protect coastlines. They act as natural barriers, reducing wave energy and protecting shorelines from erosion and storm damage. Live corals preserve water quality. Their structures filter sediments and pollutants, maintaining clean and clear water essential for marine life.
• Live corals provide tourism and recreation. They attract tourists for snorkeling, scuba diving, and marine ecotourism. Coral reefs have cultural and historical significance. They are integral to the traditions, livelihoods, and history of many coastal communities. Live corals support scientific research and education.
• They study marine biology, ecology, and climate change. Coral reefs contribute to global biodiversity and ecosystem health. Live corals are crucial for conservation and sustainability efforts. They are threatened by climate change, overfishing, and pollution. Preserving them is vital for environmental protection and climate resilience.

How to choose a live coral

Picking live corals for an aquarium requires careful consideration. They are not just beautiful; they are the foundation of coral reefs. They provide habitat and protection to many marine animals. Here are some key things to consider when choosing live coral for a reef tank:

• Tank conditions

  Corals are sensitive to water quality. Ensure the pH is between 7.8 and 8.4. Maintain salinity between 1.023 and 1.025, with nitrate levels below 5 ppm. Keep phosphate levels low, ideally below 0.03 ppm. Regular testing is crucial to maintain these parameters.

• Aquarium size

  Some corals grow large and need space. SPS corals can spread. They often need space between them to avoid aggression. LPS corals can also grow large. They need room. Soft corals usually don't need as much space but can overcrowd if not managed.

• Lighting

  Corals have different lighting needs. SPS corals usually need strong lighting. They often require T5, LED, or metal halide lights. LPS corals need moderate lighting. Soft corals usually do well in moderate to strong lighting but can also thrive in lower lighting conditions.

• Water movement

  Corals need good water movement for food and waste removal. SPS corals usually need strong water movement. LPS corals need moderate water movement, and soft corals do well in various water movements.

• Compatibility

  Some corals can harm each other. SPS corals can sting neighboring corals and compete for space. LPS corals are often large and can overshadow their neighbors. Soft corals can release chemicals that affect neighboring corals. Keep aggressive species apart.

• Feeding

  Many corals get their energy from sunlight through their zooxanthellae algae. But some, like LPS corals, need to be fed. They can eat frozen foods like brine shrimp or specialized coral foods.

• Source

  Choose sustainably sourced corals. Avoid damaging natural reefs. Some stores have aquacultured corals. They are grown in tanks instead of taken from the wild. Aquacultured corals are usually hardier and better for the environment.

Q&A

Q1. Is it okay to touch live coral?

A1. No, it's not appropriate to touch live corals. Their mucous membrane can be easily damaged, which can lead to stress and disease. Also, human skin oils can harm them. Moreover, many corals are fragile and can break or be harmed by people.

Q2. Can live corals be kept in freshwater?

A2. Live corals cannot be kept in freshwater. They need saltwater, which has a specific salinity, to survive. The freshwater would be harmful to them, just as it would be to most marine fish and other saltwater organisms.

Q3. How often should coral be fed?

A3. Feeding corals usually takes place every few days to once a week. The exact frequency can depend on the coral species and the food used. Some corals can filter feed from the water column, while others need to be directly fed.

Q4. Why is the color of live coral essential?

A4. Coral color indicates its health and the algae living in it. A vibrant color means a healthy coral with a lot of algae, which helps the coral grow. A dull or brown color can mean the coral is stressed or has lost its algae, which can harm it.

Q5. What are the signs of healthy live coral?