Flower coral, part of the vibrant reef community, is a fascinating hard coral also known as smooth flower coral. Belonging to the family Meandrinidae, its name comes from the Greek word “maiandros,” meaning “meandering,” due to the wavy ridges between its polyps’ cups.
This coral, scientifically named Eusmilia fastigiata, is unique because it’s the only species in its genus. During the day, it hides in its hard skeleton, but at night, it extends its polyps, creating a beautiful display. Let’s explore the world of flower coral and discover its role in the reef ecosystem.
Appearance
Flower corals are a colonial species characterized by its distinct appearance, with intricate and delicate-looking hemispherical mounds and large smooth-edged ridges that somewhat resemble the petals of a flower.
It forms colonies of closely packed cylindrical or column-shaped cups known as corallites.
Each of these cup-shaped corallites houses a single polyp that remains retracted during daylight hours, but when night falls, they extend translucent white tentacles with stings to capture passing prey.
During the daytime, when their tentacles are retracted, interesting ridges known as septa can be seen between each polyp cup. The tentacles of these corals are white or translucent, and when extended, make it clear as to why smooth flower coral is so closely related to jellyfish and anemones.
Flower coral can be found in various colors, often depending on the depth and water consistency, but their colors generally range from yellow-brown to brown or grey.
That said, it’s not uncommon to see a blue-green hue that changes color as light reflects off it differently.
Habitat
Like most reef-building coral, smooth flower coral prefers warmer waters and can be found scattered along the coasts of the tropical and subtropical waters of the Atlantic Ocean.
Although somewhat rare, these corals can be found natively in Trinidad and Tobago and scattered throughout the Caribbean Sea, Brazil, Bermuda, the Bahamas, the Gulf of Mexico, and Florida.
As they require photosynthesis to provide the necessary carbohydrates, flower corals require adequate light and are therefore common on the continental shelf, at depths of between 1 and 200 ft (61 meters), where they are sometimes towered by larger corals.
They are most common in the 30 – 80 feet range, predominantly found on the back and the front edges of reefs. Because of their specific habitat requirements, flower coral has been confined to the warmer waters of the Atlantic.
Diet
As with other coral species, Eusmilia fastigiata is a sessile organism (permanently fixed to a substrate). This means it cannot venture out to hunt for food but instead relies on “passive suspension feeding.”
When night falls, the coral’s polyps reach out of their daytime hiding places and extend tentacles covered in tiny hairs known as nematocysts.
These tiny nematocysts contain stinging cells that are used to paralyze and capture small invertebrates and passing microorganisms such as plankton.
Apart from this semi-active feeding, flower corals gain the majority of their energy from their symbiotic zooxanthellae algae. Like most coral, this algae is essential to the survival of the coral and sometimes provides up to 90% of the coral’s energy.
Reproduction
Reproduction of flower coral is similar to that of other cnidaria species, as it reproduces sexually, although this is a brooder species, meaning when it releases its gametes, they are already fertilized zygotes. That said, flower coral can also reproduce asexually through budding, where new polyps are formed from preexisting ones.
Once released, they develop into planula larvae, a type of zooplankton that then drift in the ocean currents.
The zooplankton develop into larvae, which move through various stages, including a medusae phase, until they settle on a suitable sea bed. From here, it goes through a metamorphosis and develops into a polyp, then begins secreting its calcium carbonate skeleton and forming a new colony. If conditions are favorable, the colony will continue to develop until maturity, when it will release its own gametes and continue the cycle.
Threats
Apart from retracting its tentacles during the day, flower coral doesn’t have much in the means of defense and is registered as critically endangered by the IUCN Red List.
Although it doesn’t have many natural predators, the biggest contributors that threaten flower coral, along with other coral faces, are humans.
Corals symbiotic algae are extremely sensitive to light intensity and water temperature. When there is a change in the water conditions, these algae become toxic to the host coral.
The flower coral then expells the algae, which leaves it with only its white calcium carbonate skeleton.
This process is known as coral bleaching and is a major concern to the ecology of the ocean, if the algae do not return to the coral promptly, it will be starved of nutrients, which can lead to their demise.
There are a variety of factors that can lead to these bleaching events, but most of them are related to the change in oceanic water temperature, which has been directly attributed to global warming through drastic climate change.
That said, changing water temperatures is not the only factor threatening this beautiful coral. Water pollution from agricultural runoff can lead to algal blooms, which can suffocate the coral.
Chemical waste leaked from industrial processes stresses the coral and its algae, while habitat destruction through unsustainable fishing practices and a lack of sustainable tourism further put this species at risk.
Although a mass global effort is implemented to protect this coral and their surrounding reefs, the rate at which they grow is slow, and recovery will take a long time.
5 More Amazing Facts about Flower Coral
- Flower coral’s intricate patterns provide shelter for tiny marine creatures.
- It’s known for its resilience in various reef environments.
- The coral’s polyps capture plankton, contributing to the ocean’s food web.
- Its hard skeleton helps form the structure of coral reefs.
- Flower coral can thrive in both shallow and deeper waters.
FAQs
How can we protect Smooth Flower Coral and other coral species?
Conservation efforts are essential, including reducing greenhouse gas emissions, practicing sustainable fishing, minimizing pollution, establishing marine protected areas, and raising awareness about the importance of coral reefs.
How fast does Flower Coral grow?
The growth rate of Smooth Flower Coral can vary based on environmental conditions, water quality, and other factors. Generally, these corals are considered to have a slow growth rate, often adding only a few millimeters to a single cm of growth each year.
Can Smooth Flower Coral recover from bleaching events?
Smooth Flower Coral, like many corals, can recover from minor bleaching events if the stress is short-lived and conditions improve. These corals are sensitive and slow to recover, making severe bleaching events catastrophic for the species.
Is there a potential medicinal or commercial use for corals like Smooth Flower Coral?
Corals, including Eusmilia fastigiata, contain chemical compounds that have shown promise in medical and scientific research, including potential anti-inflammatory and anti-cancer properties.
That said, it is a delicate process that needs to be carefully regulated in order to conserve the natural coral populations.
