One coral species is evolving to cope with climate change, a new paper reveals.

Pocillopora damicornis. Dampier Archipelago, western Australia.
Image credits coral.aims.gov.au

Researchers from the University of Miami (UM) found that the cauliflower coral (Pocillopora damicornis) evolved unique tricks against environmental change. Roughly one-third of its genome is unique among all reef-building corals — and many of these unique genes relate to immune functions, the team explains.

Unique adaptations

This wealth of genes, the team adds, may give P. damicornis a unique edge in survival amid today’s changing environments. As warmer temperatures and higher ocean acidity wreak havoc on reefs across the world, this coral — one of the most abundant and widespread reef-building corals in the world — may help us better understand how anthozoans deal with stress.

“This coral is traditionally thought of as a weed, and yet it may be one of the last corals to survive environmental changes such as climate change,” said Nikki Traylor-Knowles, an assistant professor of marine biology and ecology at the UM Rosenstiel School and senior author of the study.

For the study, the team analyzed the genetic sequences of two healthy fragments and two bleached fragments of P. damicornis. The genome was then compared to publicly available genomes of several coral and cnidarian (jellyfish) species. The results suggest that hard corals like P. damicornis rely heavily on their innate immune systems when adapting to changes in the environment.

Pocillopora damicornis. Photographed in a deep, very sheltered habitat on Houtman Abrolhos Islands, south-western Australia.
Image credits coral.aims.gov.au

That in itself isn’t very surprising. An animal’s immune system is a vital part of its survival strategy. Those with stronger immune systems are better equipped to deal with environmental changes, giving them an evolutionary edge. However, P. damicornis had way more genes related to immune functions than the team expected to find — suggesting it has a very robust immune system. As such, it would have a better shot at staying alive even under climate change scenarios, the team adds.

“The study shows that [P. damicornis] is an important coral with a very complex and unique immune system, which may explain why it is able to survive in so many different locations,” said the paper’s lead author Ross Cunning.

“This study helps us better understand how corals deal with stress,” said Traylor-Knowles. “Its complex immune system indicates that it may have the tools to deal with environmental change much more easily than other corals.”

The paper “Comparative analysis of the Pocillopora damicornis genome highlights role of immune system in coral evolution” has been published in the journal Scientific Reports.