Posted on | December 10, 2010 | Comments Off
Researchers at the Hawaiʻi Institute of Marine Biology have made a remarkable new discovery. In 2009, 83 rare corals were petitioned to be listed under the United States Endangered Species Act. If the listing is granted, it will afford higher protection and designate critical habitat for these corals but are all the species on this list really species?
A challenge to the evaluation is that coral “species” definitions are presently based on the coral skeleton, which can be so variable that it is often difficult to distinguish between groups. All 83 species on the petition can be found in the United States with 9 corals found in Hawai‘i. Identifying which of the corals on this list are endemic, rare, or at risk of extinction, may prove difficult because it is not clear which corals interbreed.
Scientists examined the genetic and structural features of all the Hawaiian species from the common genus Montipora. Of these corals, three are under evaluation for listing under the Endangered Species Act—M. dilatata, M. flabellata, M. patula, more commonly known as Hawaiian Reef Coral, Blue Rice Coral and Sandpaper Rice Coral. Surprisingly, researchers found that colony shape, color and growth form can vary wildly, and may be misleading as to their species identity.
Seven Hawaiian coral species were found to belong to one of only four closely related genetic groups. According to the genes and surface texture, this study revealed two previously unknown species complexes in Hawaiʻi; showing that corals previously thought to be very rare may interbreed with more common species.
Zac Forsman of HIMB led the investigation, “The scale of variation that corresponds to the species-level is not well understood in a lot of stony corals; this is a big problem for taxonomy and conservation,” says Forsman. “We need to determine if these species complexes contain species that are in the early process of forming, or if they just represent variation within a species. Either way, it could change our understanding of coral biodiversity.”
“This study builds on previous work by Forsman and colleagues showing that species designations in the coral genus Porites were not well-defined, either,” says co-author and Associate Researcher Rob Toonen. “As more studies like this are coming out, we are getting a clear picture that we don’t really know which coral species names are valid and which are just different growth forms of common species.”