Plankton
Plankton is a broad term used to describe the microscopic and small organisms that drift through the ocean's currents. These organisms form the foundation of marine food webs and play a critical role in supporting life on coral reefs.
While many hobbyists think of plankton as a single type of food, plankton actually includes a wide variety of organisms ranging from microscopic algae to tiny animals. Together, these organisms provide a constant source of nutrition for corals, fish, filter feeders, and many other reef inhabitants.
In natural reef environments, plankton is continuously transported through the water column, creating feeding opportunities throughout the day and night. This steady flow of nutrition is one of the reasons coral reefs are able to support such incredible biodiversity.
Why Is Plankton Important?
Plankton serves as the foundation of many marine food chains. It helps transfer energy and nutrients from the lowest levels of the ecosystem to larger organisms higher up the food web.
Within reef ecosystems, plankton helps support:
- Coral nutrition
- Fish nutrition
- Filter-feeding organisms
- Zooplankton populations
- Biodiversity
- Overall ecosystem health
Without plankton, many reef organisms would struggle to obtain the nutrition they need to survive.
What Types of Plankton Exist?
The two primary categories of plankton discussed in reef keeping are phytoplankton and zooplankton.
Phytoplankton
Phytoplankton are microscopic photosynthetic organisms that use sunlight to produce energy. They form the base of many marine food chains and provide nutrition for numerous reef inhabitants.
Zooplankton
Zooplankton are microscopic animals that feed on phytoplankton and other organic matter. Many corals and fish consume zooplankton directly as part of their natural diet.
Together, phytoplankton and zooplankton create the nutritional foundation of many reef ecosystems.
Do Corals Eat Plankton?
Yes.
Many corals are adapted to capture plankton drifting through the water column. Using specialized polyps and feeding structures, corals can trap plankton particles and digest them to obtain proteins, amino acids, fatty acids, vitamins, and other nutrients.
For many species, plankton represents one of the most natural and biologically appropriate food sources available.
Why Is Plankton Considered Natural Coral Food?
Corals have evolved for millions of years in environments where plankton is constantly available. As ocean currents move through reefs, plankton-rich water delivers a steady supply of nutrition that corals can capture and utilize.
Because of this natural relationship, many coral foods are designed to mimic the nutritional composition and particle sizes found in plankton.
The closer a food resembles natural plankton, the more likely it is to align with the feeding behaviors corals have evolved to use.
Common Misconception: Plankton Is One Specific Organism
One of the most common misunderstandings is that plankton refers to a single type of food.
In reality, plankton is a category that includes thousands of different organisms. Some are plant-like, some are animal-like, and each contributes differently to the reef ecosystem.
Understanding this distinction helps reef keepers better appreciate the diversity of nutrition available on natural reefs.
Plankton and Bioavailability
Many plankton-based foods are considered highly bioavailable because they closely resemble the natural foods corals encounter in the wild.
When nutrition is delivered in familiar forms and appropriate particle sizes, corals can often capture, digest, and utilize it more efficiently.
This makes plankton one of the most important concepts in understanding coral feeding and nutrition.
The Bottom Line
Plankton is a collective term for the microscopic organisms that drift through the water column and form the foundation of marine food webs. Consisting primarily of phytoplankton and zooplankton, plankton provides a natural source of proteins, amino acids, fatty acids, vitamins, and other nutrients that support coral growth, feeding, and overall reef health. Understanding plankton helps reef keepers better understand how corals feed and why natural reef nutrition is so important to long-term success.
