CORAL REPRODUCTION RESEARCH

Principle Investigator:

Dr. Peter Vize
Professor of Biological Science
University of Calgary
Alberta, Canada
pvize@ucalgary.ca

Research Assistants/Collaborators:

Sarah W. Davies (M.Sc. student), J. Daniel Hilton (M.Sc. student), Chris Jarabek (M.Sc. student)

Background:

Peter Vize is a molecular biologist who studies how genes control early embryonic development. When he became a professor at the University of Texas in Austin, he started working with researchers at the FGBNMS, training them to perform molecular biology techniques such as DNA cloning and sequencing. This evolved into a long standing interest in understanding the biology and ecology of how corals reproduce.

Peter and his students at the University of Calgary study all aspects of embryonic development, from the generation of gametes to how genes control embryonic morphogenesis. In corals, they are particularly interested in how broadcast spawning is regulated at the molecular level. They are working on elucidating pathways that corals use to sense environmental (solar and lunar light) and biological (other corals) factors that control spawn timing.

A second area of interest is understanding coral settlement and metamorphosis. In particular, they want to know how community interactions impact coral metamorphosis and survival.

Fertilization studies have explored the importance of spawn timing in attaining high fertilization rates and minimizing cross-species wastage. Long term monitoring of coral spawning times have allowed Peter and his students to characterize precise spawning windows, reproducible to within 7 minutes from year to year. They also have preliminary evidence for a male derived signal that may trigger spawning in females.

Research Focus:

Coordination of Mass Spawning in Corals

Research Summary:

Peter Vize has been observing mass coral spawning events for years to try and understand what influences the corals' timing. As mentioned above, he and a team of graduate students are investigating behavioral, chemical, molecular and cellular components of this event.

A colony of blushing star coral (S. intersepta) in the sanctuary. Photo: Joyce & Frank Burek

For the past three (3) years, Peter has focused on one particular species at the Flower Garden Banks--Stephanocoenia intersepta, also known as blushing star coral. This particular species of coral is gonochoric, meaning that there are separate male and female colonies.

During coral spawning events, it has been noted that the female colonies of S. intersepta always spawn later than the male colonies. What is uncertain, though, is whether the release of sperm by the male colonies is actually what triggers the female colonies to release their eggs. This is one of the mysteries Peter hopes to solve.

At East Flower Garden Bank, Peter has tagged several male and female colonies of S. intersepta. Each year he returns during the mass spawning to observe and record the exact spawning time and collect female spawn so that he can genetically identify the sperm donors. In 2007, all of the study colonies spawned on the expected schedule.

A close up view of the polyps in a colony of blushing star coral. Photo: Joyce & Frank Burek

Additional experiments are being conducted by some of Peter's graduate students.
Dan Hilton is trying to identify chemical triggers for the spawning while Sarah Davies is investigating the effects of herbivores on coral recruitment. To learn more about Dan or Sarah's work, click on their names above.

To learn more about Peter's work at the University of Calgary, you can visit the Vize Lab web page.