Associate professor Michael Hellberg and biological sciences graduate student Carlos Prada were recently published in a scientific journal for their studies over the last few years of the “sea fan” coral and how new coral species are developed.
Reproductive isolation occurs in nature when a physical barrier keeps two distinct things from interbreeding, Hellberg said. Just like lions and tigers don’t reproduce with one another in the wild, two different coral species do not often mix together.
Hellberg said scientists often worry how species form in the ocean. Tiny coral larvae float around in the water and are often hauled to different locations because of the water’s currents. This makes it easy for genes from one population to mix with another.
Prada said he began studying the survivorship of the species and how it adjusts to different environments in Puerto Rico in 2005. He noticed the species had different traits depending on the depth of the water it was located in.
While conducting experiments in Puerto Rico, Prada discovered the corals were plastics and would try to revert back to their original characteristics. Because the morphologies for the shallow and deep corals are different, the ancestor must have had both morphologies, he said.
He came to the University and had his research published in 2008, he said. Hellberg and Prada communicated with each other and decided to expand on Prada’s work.
The two men wanted to look at the differences between the shallow and deep coral in a wider geographic area. They went to the Bahamas, Curacao and Panama to conduct scuba dives to study the coral at different depths, Prada said.
“So then we found the pattern was consistent with the pattern that I found in Puerto Rico, so it’s like a widespread pattern for the species,” he said.
At different depths, the coral has different morphologies, Prada said. They transplanted shallow colonies to deeper areas and deep colonies to shallow areas. The natives survive more often than the transplanted colonies, he said.
Every six months to a year, Prada would collect pieces of the transplanted coral and treat it with Clorox to expose the fissures, he said. He then washed the pieces with alcohol and water and would observe them through a microscope.
Normally, a physical barrier separates the two populations so they cannot interbreed, Prada said. In the case of coral species, the barrier is the different habitats. It can take 50 years to make a large coral, so there is a big window of time in which ecology can wipe out the colony from the habitat, he said.
The coral takes a long time to become mature, often not reproducing until it is 35 years old, Hellberg said.
He said the next step is to look at the hybridization of the species.