Fun Soft Coral Facts For Kids

Moumita Dutta
Jan 19, 2023 By Moumita Dutta
Originally Published on Aug 06, 2021
Edited by Isobel Murphy
Fun Soft Coral Facts For Kids

Soft corals are members of the order Alcyonacea. As well as including true soft corals, this order also includes gorgonians. Soft corals are called ahermatypic since they do not take part in reef-building. However, these animals can be found in reef habitats.

Soft corals often have a fleshy or leather-like appearance. The polyps of soft corals lack a hard skeleton and instead are provided with sclerites, which are spiny and calcareous.

Each polyp has an eight-fold symmetric structure with eight tentacles. Soft corals live in association with algae called zooxanthellae. They rely on these algae for nutrition, besides using their tentacles to collect food.

Some soft corals do not require a lot of light, and in the oceans, they can be found in depths greater than their stony counterparts. As pets, these animals are quite hardy and easy to keep. As long as their reef tank fulfills all their needs, they can be a wonderful addition to any aquarium.

They can also be given brine shrimps as food in captivity. The ecological importance of these animals should not be ignored and care should be taken to maintain their populations.

To learn more about soft corals, continue reading! You can also check out some facts about the seahorse and the flatworm here.

Soft Coral Interesting Facts

What type of animal is a soft coral?

A soft coral is a kind of cnidaria belonging to the subclass Octocorallia. This subclass also includes gorgonians like sea fans, which are now considered to be soft corals as well. Soft coral polyps form giant colonies which are found in oceans throughout the world.

What class of animal does a soft coral belong to?

Soft corals belong to the class Anthozoa. They are divided into several suborders and families.

How many soft corals are there in the world?

Though the exact populations of different soft corals are not known, they are pretty commonly found in oceans and coral reefs. According to the International Union for Conservation of Nature (IUCN)Red List, the soft coral Clavularia crassa has a stable population, with an occurrence of 21528 sq ft (2000 sq m) off the Italian coast.

On the other hand, the species Spinimuricea klavereni has a decreasing trend in population with very rare sightings in its natural range.

Where does a soft coral live?

Soft corals are marine creatures found throughout the world. For example, pink sea fans occur in the Atlantic Ocean and the Mediterranean Sea. In the Red Sea, rough leather coral is very common.  Dendronephthya hemprichi can also be seen from the Red Sea to the Western Pacific Ocean.

What is a soft coral's habitat?

Soft corals can be found living in the tropical and sub-tropical waters of various oceans and seas. They also inhabit polar waters and the deep sea. They can be found in the inner reef. Since these corals do not require a lot of light, they inhabit caverns or rocky outcrops.

Who do soft corals live with?

The polyps of soft corals together form a large colony and hence, individual polyps live together. The colony also provides a home to the marine animal called the pygmy seahorse.

How long does a soft coral live?

Many soft corals display a very long lifespan, while some live comparatively shorter lives. For most gorgonians and soft corals, their life span remains unknown. However, some colonies of the genus Sinularia are estimated to live to be several hundred years old.

How do they reproduce?

Soft corals can reproduce by both asexual and sexual methods. Asexual reproduction occurs through budding in the polyps which leads to the overall growth of the colony.

In sexual reproduction, broadcaster species of polyps release eggs and sperm, which are externally fertilized, giving rise to planulae, which eventually settle down and form colonies. On the other hand, in brooder species, only male polyps release sperm, which are fertilized within the mother colony.

The new colony detaches from the parent colony and settles down nearby. Several thousand coral larvae or planulae form each year.

What is their conservation status?

The conservation statuses of some soft coral species have been listed by the International Union for Conservation of Nature (IUCN) Red List. The soft coral (Clavularia crassa) has been marked as Least Concern, while the pink sea fan and the organ pipe coral are marked as Vulnerable and Near Threatened, respectively.

Some species, like Spinimuricea klavereni and Paramuricea macrospina, are marked as Data Deficient.

The main threat faced by these corals is the destruction of their habitat and over-exploitation by humans. Declining coral reef habitats and climate change also cause significant damage to their populations.

Soft Coral Fun Facts

What do soft corals look like?

Soft corals usually have a fleshy or leathery appearance. Individual polyps in a colony are very small in size. Each polyp has eight-fold symmetry with eight tentacles which are feathery in nature.

Unlike stony corals which have a skeleton made out of calcium carbonate, soft corals are hollow and are held together by a shared tissue. This tissue has spiny spicules called sclerites.

Soft coral identification is usually based on these sclerites, which are made up of calcium carbonate. Sclerites help in providing some rigidity to the structure of soft corals. The inner core of soft corals is made up of a protein known as gorgonin.

Due to the flexible nature of soft corals, they often appear like plants swaying underwater. Soft corals are sessile in nature, meaning they are attached to a base.

Most colonies display an erect and branched appearance, while some might be bushy or whip-like. Several soft coral species have a wide range of colors. Some of the most common colors are yellow, red, orange, rust, and purple.

A soft coral polyp has eight tentacles.

How cute are they?

More than cute, soft corals appear very beautiful and give a vibrant appearance to any underwater habitat. The different species of soft corals all have certain distinct characters which make them stand out. Some soft coral species who are especially known for their beautiful appearance are members of the family Neptheidae.

How do they communicate?

In general, coral species are known to communicate by chemical means. It can be assumed that soft corals resort to a similar method in order to pass messages to one another.

How big is a soft coral?

The individual polyps in soft corals are very small and are only a few millimeters in diameter. In the pulsating xenid, the stalk of each polyp is only around 0.079 in (2 mm) long.

However, soft coral colonies are pretty big and can grow up to 11.8 in (30 cm) in size, almost twice as big as the average height of a crab. Pink sea fans and warty gorgonians have colonies measuring up to 20 in (50.8 cm).

Rough leather corals can grow to be 31.4 in (80 cm) tall.

Additionally, a soft coral colony can display a growth rate of 0.7-1.5 in (2-4 cm) every year. Stony corals, like the elkhorn coral species at 72 in (1823 cm) and the pillar coral species at 120 in (305 cm), are considerably taller than soft corals.

How fast can a soft coral move?

Soft corals do not tend to move if they have found an ideal environment. However, if they do have to move, they do so very slowly by extending the base of their colony.

How much does a soft coral weigh?

The exact weight of the different soft coral types is not known.

Research into the growth rate of rough leather corals (Sacrophyton glaucum) collected from the Red Sea revealed that the weight of this species of soft coral increased by a maximum of 1 oz (28.3 g) in six months during the summer and between 0.7-0.9 oz (20-26 g) in six months during the winter.

What are the male and female names of the species?

Male and female corals of the different soft coral species are known as male soft corals and female soft corals.

What would you call a baby soft coral?

A baby soft coral is known as a planula.

What do they eat?

Soft corals have an omnivorous diet and they mainly feed on zooplankton, phytoplankton, and bacterioplankton. Soft corals make use of their tentacles while feeding.

Many of the members of Alcyonacea form a symbiotic relationship with the algae zooxanthellae. Algae becomes the major source of nutrition in such soft corals. In the pulsating xenids, belonging to the family Xeniidae, the polyps are known to pulsate their tentacles, which is assumed to assist them in feeding.

Are they poisonous?

Some soft corals contain a very dangerous toxin known as palytoxin, which can cause severe reactions and even death in humans. Additionally, soft corals are known to produce organic compounds which make them unfit for consumption by predators.

Would they make a good pet?

Soft corals are very commonly seen in home aquariums. They are hardy in nature and can be relatively easily kept by beginners.

Soft coral tanks should have a reef environment, as this environment is ideal for these animals. A soft coral reef tank should constitute clean water and moderate light. Many soft corals are known to produce toxins, which can be gotten rid of by placing filters and activated carbon in the tank.

Planktons and brine shrimp can be given to these creatures as food. However, the species of soft corals which live in association with the algae zooxanthellae derive most of their nutrients from there.

Did you know...

Soft corals belonging to the genus Sacrophyton are known to have some really potent bioactive metabolites. These metabolites have a wide-ranging impact in health sciences and possess anti-diabetic, anti-viral, anti-tumor, and anti-inflammatory qualities. Rough leather corals (Acrophyton glaucum) produce Sacrophytol A, which shows cancer-preventive properties.

What is the difference between hard and soft coral?

There are ample differences between soft corals and hard or stony corals. As the name suggests, soft corals are much more flexible and softer than stony corals.

The main reason for this is that stony corals have a skeleton made up of calcium carbonate, which is absent in soft corals.

Instead, soft coral polyps share a common tissue that is covered with spiny structures called sclerites. The structure of both corals can be further differentiated by their tentacles, which are eight in number in the polyps of soft corals and six in the polyps of stony corals.

Hence, soft corals belong to the subclass Octocorallia, while stony corals belong to Hexacorallia.

Stony corals are primarily reef-building corals, whereas soft corals do not produce reefs, even though they live in coral reefs. A soft coral is also known to live in areas with a moderate intensity of light, unlike a stony coral.

What do soft corals do?

Some of the activities carried out by soft corals are feeding, reproducing, and defending themselves. These cnidarians are considered to be filter-feeders, as they use their tentacles to feed on planktons floating in the water.

They are capable of reproducing both via asexual and sexual methods.

As part of asexual reproduction, the polyps propagate by buds, and in sexual reproduction, they produce sperm and eggs. Soft corals are known to defend themselves by secreting certain compounds or toxins which not only alter their taste and deter predators, but also limit the growth of other corals near them.

Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! For more relatable content, check out these fire coral facts and harbor seal facts for kids.

You can even occupy yourself at home by coloring in one of our free printable soft coral coloring pages.

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Written by Moumita Dutta

Bachelor of Arts specializing in Journalism and Mass Communication, Postgraduate Diploma in Sports Management

Moumita Dutta picture

Moumita DuttaBachelor of Arts specializing in Journalism and Mass Communication, Postgraduate Diploma in Sports Management

A content writer and editor with a passion for sports, Moumita has honed her skills in producing compelling match reports and stories about sporting heroes. She holds a degree in Journalism and Mass Communication from the Indian Institute of Social Welfare and Business Management, Calcutta University, alongside a postgraduate diploma in Sports Management.

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