A mysterious coral species that was overshadowed by another, more well-known type may finally be getting its due.
The rare Caribbean Pillar Coral Dendrogyra cylindrus is among just a few Caribbean corals that form large branches, which offer key fish species refuge and help blunt the energy of storm surge as it approaches shore. Small Pillar juveniles have evaded human eyes for more than three decades-worth of surveys in the Caribbean.
In this case, timing may really be everything.
"Strangely enough, pillar corals happen to spawn just half an hour before another threatened coral that is far better studied--the Elkhorn corals," says coral reef ecologist Kristen Marhaver, PhD, CARMABI Foundation, Curaçao.
"So the reason why for so many years we've never witnessed spawning Pillar corals is that, while they were spawning, virtually all coral spawning researchers and photographers in the Caribbean were on their boats doing final preparations on their dive gear for Elkhorn coral spawning," she says. "It was literally right under our noses for years."
Now, for the first time, the species has been successfully bred and raised in the lab, according to research published in the open access journal BMC Ecology, which boasts photos of the juveniles. Marhaver, the study's lead author and TED senior fellow, recently presented these findings in a talk at the annual TED Conference in Vancouver.
The long, leggy corals form a unusual smokestack-like shape. Their mating behavior differs from that of most spawning coral species (which, as hermaphrodites, release large bundles of eggs and sperm). Pillar corals--which only spawn on a few specific nights of the year, say the researchers--build colonies that are either all-male or all-female. The males first release sperm into the seawater, shortly followed by the females releasing their individual eggs.
The process makes collection and breeding research quite the undertaking. However, Marhaver and her team have successfully reared juvenile Pillar corals in the lab. The researchers aim to learn what may may be threatening the species' survival in the wild, and plan to out-plant a small number back to the reef. This could make a difference in the species' genetic diversity, allowing their populations to adapt and become more resilient to the changing environment in the oceans, Marhaver says.
The article is "Reproductive natural history and successful juvenile propagation of the threatened Caribbean Pillar Coral Dendrogyra cylindrus."