Porites lobata

Lobe Coral

Lobe Coral (Porites lobata) Credit: Photo courtesy of the National Oceanic & Atmospheric Administration

Habitat

Porites lobata, a lobe coral, is one of the four most prominent reef-building coral species in Hawaii. Found throughout the Indo-Pacific region, this surge-tolerant coral can be found is a variety of habitats, from tidepools to depths of 150 feet (45 m). It is most common, however, on wave-exposed reef slopes between 10 and 45 feet (3 to 14 m) deep, in a zone below the cauliflower coral.

Biology

Depending upon environmental conditions, lobe coral can be found in a variety of growth forms, from thin, bottom-hugging crusts to huge solid domes more than 20 feet (6 m) across. This massive coral grows more slowly than branching forms, adding a fraction of an inch (about 1 cm) per year to its dimensions. But, colonies may live for many years and can grow to immense sizes. Despite the massive size of some colonies, however, only the outermost four one-hundredth of an inch (1 mm) is actually living coral tissue.

Individual coral organisms, called polyps, are simple vase-shaped creatures. Each has a central mouth, surrounded by a ring of tentacles. Lobe colonies consist of thousands of polyps, all descendants of one original founding individual. Colony polyps are connected to one another by both their skin like layer and sac like gut cavities.

Many corals can function as carnivores, using their tentacles to capture small planktonic animals drifting over the reef. Special stinging cells that line the surfaces of the polyps' tentacles entangle and paralyze their prey. Other corals are suspension feeders, using hair-like structures called cilia to collect particles of organic matter that drift down from above. The polyps of lobe coral are so small that researchers question if they are actually capable of capturing prey.

But, corals also act as primary producers. Single-celled algae called zooxanthellae live within the tissues of reef-building corals in a symbiotic relationship. Using sunlight and nutrients from the water and their coral hosts, zooxanthellae generate energy-rich compounds through photosynthesis. These carbon-rich products may be particularly important in the energy budget of lobe coral.

-- From the Waikiki Aquarium

Sequencing Plan

This organism was sent to The Genome Institute for survey sequencing (13,824 whole genome shotgun reads) to attempt to make an initial assessment of the genomic landscape as an aid in determining which coral genome would be sequenced. The survey sequence is complete, and the report was sent to the NHGRI for review. It was not approved for sequencing in the September 2005 review cycle. The National Human Genome Research Institute (NHGRI), National Institutes of Health (NIH), provided the funding for the Porites lobata genome survey sequence.

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Contacts

Name	Affiliation
Patrick Minx	The Genome Institute, Washington University School of Medicine
Gary Ostrander	Department of Biology, Johns Hopkins University

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