# How Some Animals Use Sunlight: The Surprising Truth of Animal Photosynthesis
Most people know plants make food through photosynthesis. But few realize a small number of animals can also use sunlight for energy. True animal photosynthesis does not happen in animal cells themselves. Instead, these creatures form close partnerships with tiny photosynthetic algae.
## What Is Animal Photosymbiosis
Animals cannot produce chlorophyll on their own. They host living algae inside their body tissues. The algae perform photosynthesis, turning sunlight, water and carbon dioxide into sugar. The animal gets part of this sugar as food. In return, the animal gives the algae a safe, stable home and access to sunlight. Scientists call this relationship photosymbiosis.
## Famous Examples
### Sea Slugs
Some sea slugs steal chloroplasts from the algae they eat. They keep these plant cell parts inside their cells for weeks. The stolen chloroplasts continue photosynthesis and supply sugar to the slug. This sea slug can survive for months only using sunlight after feeding once.
### Corals
Reef-building corals are the most well-known example. Tiny algae live inside coral polyps. The algae feed the coral with sugar, while the coral provides shelter. This partnership creates the colorful coral reefs. When water becomes too warm, corals expel the algae, turn white, and may die. This event is known as coral bleaching.
## Benefits of This Partnership
– Extra food source when regular food is scarce
– Helps animals survive in nutrient-poor ocean water
– Supports the growth of large coral reef ecosystems
## Limitations
This sunlight-based energy cannot fully replace hunting or filtering food. These animals still need to eat sometimes to get nutrients like nitrogen. The algae or stolen chloroplasts will break down over time and cannot last forever.
## Common Misconception
These animals do not have built-in photosynthesis genes. They cannot make chlorophyll. Without their algae partners, they lose the ability to harvest solar energy. No animal on Earth can perform photosynthesis completely on its own.
## Conclusion
Animal photosymbiosis shows amazing cooperation between different living things. These special partnerships help animals survive in tough ocean environments and create some of the richest ecosystems on our planet.