Corals primarily use oxygen for respiration.
The Role of Oxygen in Coral Respiration
Like most animals, coral polyps require oxygen to survive. This vital gas is essential for the process of cellular respiration. Respiration is how coral cells convert energy stored in food (such as carbohydrates received from their symbiotic algae or captured prey) into a usable form of energy called adenosine triphosphate (ATP). This energy powers all of the coral's life functions, including growth, reproduction, and maintaining its structure.
Based on the provided reference:
The coral uses the oxygen for respiration, and the carbohydrates for much of its daily energy supply.
This highlights that oxygen is directly consumed by the coral organism for its metabolic needs.
Oxygen Source and Symbiosis
A significant source of oxygen for many reef-building corals comes from their remarkable symbiotic relationship with tiny algae called zooxanthellae (a type of dinoflagellate) that live within their tissues.
The reference states:
The coral host layer provides carbon dioxide and nutrients that the zooxanthellae use in photosynthesis, the light-driven energy process in which plants use carbon dioxide and water to produce carbohydrates and oxygen.
During the day, when sunlight is available, these zooxanthellae perform photosynthesis. Photosynthesis uses carbon dioxide and water to produce carbohydrates and oxygen. The oxygen produced by the algae is then readily available for the coral polyp to use for its own respiration. This symbiotic exchange is crucial: the algae get CO2 and nutrients from the coral, and the coral gets oxygen and carbohydrates from the algae.
At night, or in conditions with low light, the algae's photosynthesis stops, and the coral must obtain oxygen from the surrounding seawater through diffusion.
Respiration Overview
Coral respiration is the reverse process of photosynthesis in terms of gas exchange.
Here's a simplified look at the process:
| Process | Reactants (Used) | Products (Produced) |
|---|---|---|
| Coral Respiration | Oxygen + Carbohydrates | Carbon Dioxide + Water + Energy (ATP) |
| Zooxanthellae Photosynthesis (Day) | Carbon Dioxide + Water + Light | Carbohydrates + Oxygen |
In summary, corals are constantly respiring to fuel their life processes, and they rely on oxygen for this critical function, often getting a significant supply directly from their symbiotic algal partners during the day.
