Ocean Motion

Scientists say pulsing

corals make their motion to bring in needed nutrients

 The corals called the xeniids open and close all day and night with very rare short breaks. The Hebrew University's Maya Kremien says that these look like "amazing pulsating  carpets.

 "Kremien and coworkers were wondering WHY these corals move nonstop. And now a clue is found: The motion they make mixes up the water. This helps in two different ways. First of all it brings up nutrient-rich water and also flushes excess oxygen.

 Many corals survive with photosynthesis. Photosynthesis uses light  to turn CO2 (carbon dioxide) and water into their breakfast, lunch and dinner. The corals do not do the photosynthesis process the algae living inside them do it. The algae inside them share the foods they  create with the coral it is inside of. Team Kremien says that the pulsing corals get ALL of their food from the algae that lives inside it. The type of algae that live inside pulsing corals are the ones that have single celled organisms. This type of algae works like a very green plant.

 Also photosynthesis produces oxygen. In previous studies - not on pulsing corals-scientists found out that too much oxygen can slow down photosynthesis  There is a maximum amount of CO2 a coral can hold which the algae need to use for photosynthesis. Team Kremien used to suspect that the xeniid corals is pushing some of the oxygen . This process bring in extra rich water in carbon dioxide. It would help the xeniids if a buildup of more oxygen was another one of their problems.

 The experiment used to find it out was to keep xeniids in EXTRA high levels of oxygen- the scientists compared it with the corals in a perfect level. As hypothesized photosynthesis was slowed down. And so the swishing water does help remove oxygen. The motion may also bring food to the coral.

 Xeniids are the only corals that do swish.