Coral: What Does it Eat?

Summary

Coral reefs are vibrant ecosystems, home to coral polyps that form the foundation of the reef structure. These tiny animals build their skeletons by depositing calcium carbonate, creating vast, living reefs. The polyps rely on a symbiotic relationship with algae, which provide up to 95% of their food through photosynthesis. At night, polyps extend their tentacles to catch zooplankton and other particles. They also use mucus to trap dissolved nutrients. Coral colonies share nutrients through interconnected stomachs, allowing polyps to function like a single organism. Together, these processes make corals some of the most resourceful creatures on Earth.

Takeaways

• 😀 Coral reefs are among the liveliest ecosystems on Earth, supporting complex interactions beyond what is visible.
• 😀 Corals are made up of tiny animals called coral polyps, which are cousins of jellyfish.
• 😀 A single coral is made up of hundreds or even thousands of polyps, and together they build the reef, millimeter by millimeter.
• 😀 Each polyp has a stomach-like structure with a mouth at the top and is surrounded by a hard skeleton that forms part of the reef.
• 😀 Coral polyps build their skeletons from calcium carbonate, also known as limestone, which contributes to the reef's growth.
• 😀 Coral polyps derive energy for building from a symbiotic relationship with tiny algae called zooxanthellae, which photosynthesize and provide food for the polyps.
• 😀 Zooxanthellae produce up to 95% of the food corals need, including oxygen, sugars, and fats, while corals provide the algae with carbon dioxide, nitrogen, and phosphorus.
• 😀 This symbiotic relationship between the algae and corals is mutually beneficial, with algae also contributing to the coral’s vibrant colors.
• 😀 At night, coral polyps use long tentacles to capture zooplankton and other food particles, using stinging cells to pierce and paralyze their prey.
• 😀 Coral polyps also secrete mucus, which helps trap dissolved nutrients from the water and sediment, aiding in their feeding.
• 😀 In coral colonies, polyps share nutrients via a tissue called coenosarc, allowing them to function as a unified organism.

Q & A

What are coral polyps and how do they contribute to a coral reef?

Coral polyps are tiny animals that form the building blocks of coral reefs. They secrete calcium carbonate to build their own skeletons, which, over time, creates the structure of the reef.

What is the relationship between coral polyps and zooxanthellae algae?

Coral polyps have a symbiotic relationship with zooxanthellae algae. The algae perform photosynthesis, producing up to 95% of the food that the corals need, while the corals provide a protected space and essential nutrients to the algae.

How do coral polyps obtain energy for building their skeletons?

Coral polyps obtain energy primarily from the zooxanthellae algae inside them, which photosynthesize and produce sugars, oxygen, and fats. The polyps also feed on zooplankton at night.

What role does calcium carbonate play in the coral reef?

Calcium carbonate, also known as limestone, is secreted by coral polyps to form their skeletons. This process contributes to the growth and development of the coral reef.

What are nematocysts and how do they help coral polyps capture food?

Nematocysts are stinging cells found on the tentacles of coral polyps. These cells release toxins to paralyze prey, allowing the polyps to capture and consume zooplankton and other food particles.

How do coral polyps feed at night?

At night, coral polyps extend their tentacles to catch passing zooplankton and other food particles. The tentacles, equipped with nematocysts, paralyze the prey and bring it to the polyps' mouths.

What is the function of the mucus layer produced by coral polyps?

The mucus layer produced by coral polyps acts like flypaper, trapping dissolved nutrients from the surrounding water and sediment. The polyps then draw these nutrients into their stomachs using hair-like projections called cilia.

What is coenosarc and how does it benefit coral polyps?

Coenosarc is a tissue that connects the stomachs of individual polyps in a coral colony. It allows polyps to share nutrients, enabling them to work together as a single organism, increasing their overall efficiency in feeding and growth.

What percentage of the coral's food is produced by the zooxanthellae algae?

Zooxanthellae algae produce up to 95% of the food that coral polyps need through photosynthesis.

Why are coral reefs considered one of the liveliest places on Earth?

Coral reefs are teeming with life and are formed by the collaboration of many organisms, including coral polyps, algae, fish, and invertebrates. The complex relationships and diverse species make coral reefs incredibly vibrant and dynamic ecosystems.