Coralline algae are a type of red algae. They belong to the order Corallinales. These algae are hard because they have calcareous deposits in their cell walls.
The colors of these algae are mostly pink or some shade of red. But, some can be purple, yellow, blue, white, or gray-green.
They are found in marine waters all over the world. Only one kind lives in freshwater.
Where Can You Find Coralline Algae?
If you look closely at almost any rocky shore or coral reef, you will see lots of pink to pinkish-grey patches. These patches are actually living crustose coralline red algae.
There are over 1600 kinds of nongeniculate coralline algae. They are found everywhere in the world’s oceans. Often, they cover almost all of the rocky areas.
The only exception is one species, Pneophyllum cetinaensis, which is found in freshwater.
What Role Do Coralline Algae Play in The Environment?
Coralline algae play a big role in the ecology of coral reefs. Sea urchins, parrot fish, and some types of mollusks feed on coralline algae.
In the Mediterranean Sea, coralline algae are the main builders of a typical algal reef, called the Coralligène.
Despite their importance, many people who study algae don’t know much about them.
What Do Coralline Algae Look Like?
Coralline algae have been divided into two groups. The geniculate corallines are branching and tree-like. They attach to the bottom by crustose or calcified, root-like holdfasts.
Nongeniculate corallines form crusts that are a few micrometers to several centimeters thick.
They grow very slowly and are found on rock, coral skeletons, shells, other algae, or seagrasses.
Where Do Coralline Algae Live?
Corallines live in varying depths of water, from the intertidal zone to 270 m deep. Some species can live in brackish or hypersaline waters.
Only one strictly freshwater coralline species exists. It can tolerate a wide range of turbidities and nutrient concentrations.
How Do Coralline Algae Grow?
Corallines, especially encrusting forms, are slow growers. They expand by 0.1–80 mm every year. All corallines start with a crustose stage. Some later become frondose.
They also have ways to avoid being overgrown by other ‘fouling’ algae. They rely on waves to disturb their thalli or wait for herbivores to eat the potential encrusters.
What Is the Evolutionary History of Coralline Algae?
The corallines have a good fossil record from the Early Cretaceous onwards. This matches with molecular clocks that show the divergence of the modern species beginning in this period.
However, non-mineralizing coralline algae are known from the Silurian period, showing that the lineage has a much longer history than molecular clocks would show.
What Is the Taxonomy of Coralline Algae?
The group’s internal taxonomy is in a state of change. Molecular studies are proving more reliable than morphological methods in approximating relationships within the group.
Crystal morphology within the calcified cell wall of coralline algae was found to have a high correspondence with molecular studies.
What Is the Economic Importance of Coralline Algae?
Because of their calcified structure, coralline algae have a number of economic uses.
They are used as soil conditioners, in the preparation of dental bone implants, as a food additive for cattle and pigs, and in the filtration of acidic drinking water.
They are also a colorful component of live rock sold in the marine aquarium trade.
Coralline algae Characteristics
| Care Level: | Moderate |
| Growth Rate: | Slow |
| Nutrient Uptake: | None |
| Required Lighting: | Moderate High |
| Required Water Flow: | Moderate High |
| Is Palatable? | No |
| Maximum Size: | 10 in (25.4 cm) |
Scientific Classification
| Kingdom: | Plantae |
| Order: | Corallinales |
| Scientific Name: | Coralline algae |
| Conservation Status: | Unknown |