Coral Found Living In Caves In Indo-Pacific
October 13, 2012

Coral Named Leptoseris Troglodyta Sheds Light On Coral-Algal Symbiosis

Alan McStravick for - Your Universe Online

Troglodyte, noun:

1) a member of any of various peoples (as in antiquity) who lived or were reputed to live chiefly in caves;

2) a person characterized by reclusive habits or outmoded or reactionary attitudes;

3) your crazy uncle who, over Thanksgiving dinner, just feels he has to tell you why it´s your political leanings responsible for all that is wrong in this country;

Merriam-Webster is going to have to add a fourth entry for the definition.

Coral specialist Dr. Bert W. Hoeksema of Naturalis Biodiversity Center in Leiden, The Netherlands, published a description of a new coral species that lives on the ceilings of caves in Indo-Pacific coral reefs. Its scientific name, Leptoseris troglodyta, is derived from the ancient Greek, meaning “one who dwells in holes”, or a cave dweller.

This new species of coral differs from its closest relatives by the size of its smaller polyps and by the absence of symbiotic algae, so called zooxanthellae. The troglodyta distribution overlaps with the Coral Triangle. The triangle is famous for its high marine species richness. This makes it an especially favored locale for marine zoologists of Naturalis to visit.

The symbiotic algal relationship of reef corals, typically found in shallow tropical seas, is necessary for the coral´s survival and growth. If there were no algae, many coral reefs simply would not exist. As seawater temperature goes through periods of elevation, many coral reefs lose their algae. This accounts for a visible dramatic whitening of the reefs. This disease is known as bleaching.

Sunlight, a necessity for most coral, has difficulty piercing to depths of 40 meters or more. Leptoseris troglodyta, however, is believed to not only exist at these depths but also to thrive. In these greater depths, impenetrable to the sun´s light and warmth, seawater is typically colder and corals at this depth may be less susceptible to bleaching than corals at shallower depths. The newly discovered skeletal structures of the new species, despite its smaller size and lack of zooxanthellae, is believed to be related to the genus Leptoseris even though they have never been found below a depth of 35 meters.

The research team´s discovery of this new species will help to shed light on the nature of the relationship between reef corals and algae. The new species has adapted to a life without them. As a direct result, its growth rate may be severely limited, which would be convenient because space is limited on cave ceilings. The research team has provided a detailed description of the species which was published in the open access journal ZooKeys.

The authors of the study also recognized the invaluable research and fieldwork conducted by partner organizations, such as the Coral Reef Research Foundation of Palau, the University of San Carlos and The Nature Conservancy, among others.