Coralline Algae
Rhodophyta Corallinales
The coralline algae color range includes pink, red, and purple. They are found around the world. Easily observable in tidepools, they are a critical building block for coral reefs. Coralline has existed since the Jurassic area and is being studied by paleobiologists to understand evolution and weather patterns among other applications through well-preserved coralline fossils.
SPECIES IN DETAIL
Coralline Algae
Rhodophyta Corallinales
CONSERVATION STATUS: Safe for Now
CLIMATE CHANGE: Laboratory Evidence
At the Aquarium
Just like how you can find coralline all over the world, you can find it all over the Aquarium. Look for purple and/or pink rocks in the following exhibits: Tropical Reef, Baja California, Northern Pacific .
Geographic Distribution
These algae are found worldwide.
Habitat
Coralline algae is found around the world and can be found as shallow as the tidal zone to a depth of 271 meters (890 feet). Branching coralline found in the tidal zone have a firm texture but are still flexible enough to withstand the tide without breaking. They are preyed upon by chitons, sea urchins and limpets.
Physical Characteristics
Coralline algae is often purple or pink, although it can vary in coloration. Coralline algae is made from magnesium calcite (calcium carbonate also known as limestone). There are two groups of coralline— encrusting and articulated (branching). Encrusting coralline generally cover rocks and other hard surfaces and can be very thin or up to several centimeters thick. Branching coralline can come in a variety of shapes such as fronds, twigs and spheres.
Size
Growth rates are fairly slow, but can range from 0.1 to 76 millimeters (0.004 to 3 inches) per year, with branching coralline growing faster as it has more surface area for increased photosynthesis. Faster growing coralline (both articulated and encrusting) may be an early colonizer for an area and may be replaced by a slower growing coralline later on.
Diet
They are photosynthetic, drawing their nutrients through radiant energy and sunlight.
Reproduction
When coralline algae is ready to reproduce, they create an external cavity on their crust that contains their reproductive material. They release this reproductive material into the water. Studies of Porolithon onkodes (an encrusting coralline) show that the algae reproduce about once a year and are able to start reproducing several months after settling.
Behavior
Some species of encrusting coralline can shed (slough off) their top layer to protect themselves from fouling algae or epiphytes (organisms that grow on other plants). Some species of coralline can also release a chemical to deter epiphytes (a nonparasitic organism that grows on the surface of a plant) and pests.
Adaptation
Coralline algae are able to withstand herbivore predators due to heavy calcification. This adaptation has also been observed to have a mutual plant protection strategy with sea grass; sea turtles were observed eating less sea grass when there was coralline present, and the coralline had stronger growth rates when growing alongside the sea grass.
Longevity
Some types of coralline display banding (like tree rings) that can help determine growth rate and age. Coralline has been shown to live for many years.
Conservation
While coralline algae is sensitive to ocean acidification, studies have shown that encrusting coralline algae can gain tolerance to ocean acidification after multiple generations. Coralline algae are a coral reef building block, providing a hard substrate for coral to grow on as well as acting as the cement between coral heads.
Special Notes
There is one species of freshwater coralline algae. Coralline algae has been traced to the Jurassic era. Certain species of coralline are so similar to human bone structure that they have been used for bone graft substitutes, notably for the spine and teeth.
SPECIES IN DETAIL | Print full entry
Coralline Algae
Rhodophyta Corallinales
CONSERVATION STATUS: Safe for Now
CLIMATE CHANGE: Laboratory Evidence
Just like how you can find coralline all over the world, you can find it all over the Aquarium. Look for purple and/or pink rocks in the following exhibits: Tropical Reef, Baja California, Northern Pacific .
These algae are found worldwide.
Coralline algae is found around the world and can be found as shallow as the tidal zone to a depth of 271 meters (890 feet). Branching coralline found in the tidal zone have a firm texture but are still flexible enough to withstand the tide without breaking. They are preyed upon by chitons, sea urchins and limpets.
Coralline algae is often purple or pink, although it can vary in coloration. Coralline algae is made from magnesium calcite (calcium carbonate also known as limestone). There are two groups of coralline— encrusting and articulated (branching). Encrusting coralline generally cover rocks and other hard surfaces and can be very thin or up to several centimeters thick. Branching coralline can come in a variety of shapes such as fronds, twigs and spheres.
Growth rates are fairly slow, but can range from 0.1 to 76 millimeters (0.004 to 3 inches) per year, with branching coralline growing faster as it has more surface area for increased photosynthesis. Faster growing coralline (both articulated and encrusting) may be an early colonizer for an area and may be replaced by a slower growing coralline later on.
They are photosynthetic, drawing their nutrients through radiant energy and sunlight.
When coralline algae is ready to reproduce, they create an external cavity on their crust that contains their reproductive material. They release this reproductive material into the water. Studies of Porolithon onkodes (an encrusting coralline) show that the algae reproduce about once a year and are able to start reproducing several months after settling.
Some species of encrusting coralline can shed (slough off) their top layer to protect themselves from fouling algae or epiphytes (organisms that grow on other plants). Some species of coralline can also release a chemical to deter epiphytes (a nonparasitic organism that grows on the surface of a plant) and pests.
Coralline algae are able to withstand herbivore predators due to heavy calcification. This adaptation has also been observed to have a mutual plant protection strategy with sea grass; sea turtles were observed eating less sea grass when there was coralline present, and the coralline had stronger growth rates when growing alongside the sea grass.
Some types of coralline display banding (like tree rings) that can help determine growth rate and age. Coralline has been shown to live for many years.
While coralline algae is sensitive to ocean acidification, studies have shown that encrusting coralline algae can gain tolerance to ocean acidification after multiple generations. Coralline algae are a coral reef building block, providing a hard substrate for coral to grow on as well as acting as the cement between coral heads.
There is one species of freshwater coralline algae. Coralline algae has been traced to the Jurassic era. Certain species of coralline are so similar to human bone structure that they have been used for bone graft substitutes, notably for the spine and teeth.