1) They absorb food particles through small tentacles that capture floating food. These tentacles can be retracted for protection against predators, like starfish, or sometimes they protrude venomous tentacles to hinder the growth of competing coral species.
2) The primary way they eat is through photosynthesis! Corals have a special relationship with algae called zooxanthellae - try saying that three times fast! The relationship between corals and the algae are called a symbiotic relationship. This means that corals provide a safe habitat for the algae, and in return, the algae provide food to the coral.
Why do corals turn white?
Under heat stress, the algae produce toxins that harm the coral, which then ejects the algae. Since algae give coral their color, what’s left behind is the coral’s clear tissue, revealing its white skeleton, this is what’s known as bleaching. If corals don’t get their algae back or find a new algae partner, they may starve and die. Bleaching is often caused by heat from rising sea temperatures, and you can monitor coral health on NOAA’s Coral Reef Watch webpage (here’s the link for Curaçao! - https://coralreefwatch.noaa.gov/product/vs/gauges/abc_islands.php). Currently, Curaçao is at Alert Level 2 for elevated stress, and this is expected to last for two more months.
Wait, why are some corals neon colored?
Some corals in addition to excreting their algae, turn a neon blue or green. Like me, corals put sunscreen on as well! This neon color is another last defense to rising temperatures and protects them from UV light when the algae have been ejected.
