Colpophyllia
Monotypic genus of boulder brain coral, a Caribbean reef-builder.
Colpophyllia is a genus of stony coral from the family Mussidae, and it contains just one species: Colpophyllia natans. You might know it as the boulder brain coral or large-grooved brain coral. This coral is a major reef-builder in the Caribbean, and it stands out for its big, dome-shaped colonies that can reach up to 2 meters across.
The colonies are usually broadly domed, and the older they get, the more curved they become. Younger ones can be flat-topped discs. Like other brain corals, the skeleton’s surface is a maze of winding valleys and ridges, which gives it a brain-like look. The ridges are brown with a single groove on top, while the valleys are tan, green, or white and are all about the same width—typically 2 centimeters. The polyps only come out to feed at night.
Because of its sturdy shape, size, and slow growth, boulder brain coral handles tough conditions better than smaller, more fragile corals like the plate-like lettuce coral. For example, it’s less likely to get smothered by algae blooms and survived Hurricane Allen off Jamaica in 1980. Caribbean corals can bleach from high water temperatures and sunlight. A 2005 study compared bleaching in *C. natans* and the finger-like *Porites porites*: both bleached about the same amount, but only 8% of the affected *C. natans* died, versus 56% of *P. porites*. However, bleaching also triggered White Plague Type II, which killed 42% of the *C. natans* over nine months—nearly as high as the death rate for *P. porites*.
You’ll find boulder brain corals on reefs in the Caribbean Sea and Gulf of Mexico, especially off Belize, the Yucatán Peninsula, southern Florida, Puerto Rico, the Virgin Islands, and Cuba. They’ve been in the fossil record since the early Pliocene. They’re common on shallow reef ledges and slopes, down to about 50 meters, but they’re usually closer to the surface.
*C. natans* is a hermaphroditic broadcast spawner: each polyp releases both eggs and sperm at the same time to boost fertilization. After fertilization, the zygote becomes a tiny larva called a planula, which swims to a good spot, anchors, and starts a new colony. This method often fails at several stages, so few new colonies survive.
This coral is hit by more diseases than most others in its area—seven in total, which puts it among only 22 coral species worldwide with more than three.
Quick Facts
- Taxon
- Colpophyllia natans
Facts from the source article.
Lore & Background
Colpophyllia natans forms large, broadly domed colonies that increase in curvature with age, occasionally flat-topped when younger. Its surface features a network of winding ridges and valleys, with brown ridges indented by a single groove and valleys that are tan, green, or white, uniform in width up to 2 centimetres. The polyps extend their tentacles only at night. The species is hermaphroditic and a broadcast spawner, releasing gametes synchronously; after fertilization, the planula larva settles on suitable substrate to form a new colony, though reproductive success is low. Colpophyllia natans is susceptible to more coral diseases than most corals in its habitat, including seven known diseases such as black band disease, yellow-band disease, white plague types I, II, and III, dark spot, and skeletal anomalies. It is long-lived, with specimens capable of living over two hundred years.
Reader's Guide
Colpophyllia natans is a significant reef-building coral in the Caribbean Sea and Gulf of Mexico, found off Belize, the Yucatán Peninsula, southern Florida, Puerto Rico, the Virgin Islands, and Cuba. Its robust shape and slow growth allow it to survive conditions that kill smaller, more fragile corals, such as the plate-like lettuce coral. It weathered Hurricane Allen off Jamaica in 1980 and showed lower mortality from bleaching compared to Porites porites in a 2005 study: only 8% of bleach-affected C. natans colonies died versus 56% of P. porites. However, bleaching triggered widespread White Plague Type II, causing 42% mortality in C. natans over nine months. The species is identifiable in fossil records since the early Pliocene. Its susceptibility to disease is notable, with seven afflictions documented, including a particularly aggressive white plague (WPL III) that attacks only very large colonies of C. natans and Montastraea annularis. Despite this, its longevity and dominance on shallow reef ledges and slopes underscore its ecological importance.
Did You Know?
- Colpophyllia natans is the only species in the genus Colpophyllia.
- Its colonies can live for more than two hundred years.
- The species is susceptible to seven different coral diseases, more than most corals in its habitat.
- It is one of the Caribbean corals most afflicted by black band disease.
More in Brain and Merulinid Corals 1-24
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