What Do Corals Eat?

To one extent or another, corals do require a certain amount of light to survive. Some corals, however, depend less on light than they do onnutrients extracted from the water for their nutrition.

Types of Coral Food

While many species of corals contain symbiont zooxanthellae algae that produce nutrients by photosynthesis from light, mostsoft corals, zoanthids, and gorgonians depend almost exclusively on ingesting浮游植物(小水性植物和藻类)for their nutritional needs, as well as floating detritus and slow-moving invertebrate larvae.

Anotherimportant source of food for corals is bacterioplankton, which consists of free-living bacteria and the bacteria associated with decaying materials in the water (onmucus, dead plants, and other particulate matter) thatare commonly called detritus or reef snow. Almost all corals feed heavily on bacterioplankton. Other food sources include floating eggs, zooplankton (free-swimming microorganisms) and non-swimming organismsknown as pseudoplankton.

The fourth category of food utilized by corals is Dissolved Organic Material (DOM), which is absorbed across cell membranes directly into the coralfrom the water.

Many of thecoralswith larger polyps (e.g.,CynarinaandCatalaphyllia) are capable of capturing and eating larger food items, including the occasional small fish. Some corals (particularly Gorgonians and soft corals) may select their food based more on the size of the plankton, rather than its composition. Some of the small polyp corals are also aggressive feeders, trapping and eating large food items.

Nutrition Supplements

If you have live corals in your aquarium, you are probably wondering what foods your corals eat to supplement the nutrition provided by their resident zooxanthellae algae. You could just make a slurry of a variety of different foods thatcover the entire spectrum (the "shotgun method" approach) and load it into your aquarium, allowing the corals to select what they want from the mix. But, the uneaten food in the mix is guaranteed to increase your nitrate level in a short period. Or you can fine-tune the supplement to the requirements of your specific corals and target feed them with a turkey baster or syringe that applies the food directly onto the coral's tentacles.

Many corals will benefit from the food that you feed the fish and invertebrates in your tank. When meaty foods float by or land on corals, they will be consumed if the food is digestible by the coral. Copepods, Amphipods,Brine Shrimpand Mysis Shrimp will also be consumed by many corals. Copepods and Amphipods are quiteeasy to cultivatein a refugium. Brine Shrimp eggs can be inexpensively hatched and grown in a simpleDIY Brine Shrimp Hatchery. It is difficult to generalize the food requirements for groups of corals (LPS, SPS or soft) as there are always a few renegades in each group thathave a more selective diet. We highly recommend obtaining a good reference book on corals to determine what your specific corals feed on. One book thatwe highly recommend isAquarium Corals - Selection, Husbandry and Natural Historyby Eric H. Borneman. The sections devoted to each coral provide detailed information on what thecorals feedon in the wild. There is also an excellent chapter on how tofeed corals in your aquarium.