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| Phylum Cnidaria > Class Anthozoa > Subclass Zoantharia/Hexacorallia > Order Ceriantharia |
| Peacock
anemones Order Ceriantharia updated Oct 08
Where seen? These elegant animals with long colourful tentacles are commonly encountered on many of our shores. They are often seen in soft, silty muddy areas, as well as in sandy areas near seagrasses. At low tide during a cool morning or evening, peacock anemones in a pool of water might continue to extend their tentacles. Otherwise, they are often overlooked because their long, colourful tentacles are retracted completely into their sand-coloured tubes. Do watch your step to avoid stepping on them. What are peacock anemones? Peacock anemones are Cnidarians that belong to the same Class Anthozoa as sea anemones. There are 50-75 known species of peacock anemones in three families. Features: Up to 30cm in diameter with tentacles expanded, those seen from 5-15cm in diameter. The peacock anemone is a large, solitary polyp that burrows in soft ground and lives permanently in a tube. So it is also sometimes called the tube anemone or the burrowing anemone. The peacock anemone has two types of tentacles. An outer ring of long graceful tentacles called the proximal tentacles. Some species have only one ring of proximal tentacles, others have several. These long tentacles gather food from the water. There is an inner ring of shorter tentacles that ring the central mouth, called the distal tentacles. These short tentacles tuck food into the mouth. Peacock anemones come in many different colours and patterns, hence their common name. The short tentacles may be a different colour from the long tentacles. The long tentacles may be banded or variegated. Sometimes, peacock anemones are encountered with their long tentacles coiled in spirals. A peacock anemone has stingers like other Cnidarians. A peacock anemone makes its tube using specialised stingers called ptychocysts. Only peacock anemones have ptychocysts. These stingers create adhesive strings that mat together with sand and slime and hardens to form a tube that has been described as leathery, felt-like and parchment-like. The tube can be more than 1m length in some peacock anemones! Only a short part of the tube sticks out above the ground. The rest is buried in the ground. Often, at low tide, all you will see of a peacock anemone is a short portion of its soft tube that sticks out of the ground. Please don't try to dig up a peacock anemone. You will hurt it and it may die if it is not properly anchored and gets washed away with the incoming tide. The peacock anemone doesn't have a 'door' to close the opening of its tube. To seal the tube and reduce water loss at low tide, the top part of the tube often flops over, with the animal hidden deeper in the ground. The peacock anemone's body column is long, narrow and smooth. It doesn't have verrucae like sea anemones. The body column comes in many colours from white to purple. Being adapted to live in soft sediments, its body column doesn't end in a flattened pedal disk. Instead, it has a smooth tip called the physa. This tip can be expanded into a bulbous shape and is used to burrow with and to anchor itself in the soft ground. Strong muscles along the length of the body column allows it to retract completely into its tube in a blink of an eye. The peacock anemone cannot tuck its tentacles into its body column like sea anemones do. Instead, it bundles its tentacles together and pulls everything into the protective tube. Sometimes confused with sea anemones. Here's more on how to tell apart animals with a ring of smooth tentacles. What do they eat? Peacock anemones do not harbour symbiotic algae (zooxanthallae). They feed on plankton and suspended food particles which they gather from the water. Peacock anemones have potent stingers that can even be released into the water. These floating stingers can seriously affect creatures such as fishes and corals. (more about stingers on the Cnidria page) Peacock Babies: They reproduce by releasing eggs and sperm into the water. The larvae are tiny and drift with other plankton before settling down to become a new peacock anemone. Here is a photo of a tube anemone larva on Image Quest 3-D Marine Library Peacock anemones are also known to reproduce asexually. Some can also reproduce by budding. Peacock friends: Various animals may live with a peacock anemone. Small black feathery fanworm-like creatures called Phoronid worms may be found near peacock anemones. Is it said some small crabs (Lissocarcinus laevis) also live inside the tube with the anemone and some shrimps (Periclimenes sp.) are associated with the peacock anemone. Human uses: Peacock anemones are sometimes taken for the live aquarium trade. However, they do not make good tank mates as their floating stingers affect other creatures in the tank. Their burrowing habit and long body columns means they require deep tank beds. They also only take suspended food. This makes them difficult to keep alive in a home aquarium. Status and threats: Peacock anemones are not listed among the threatened animals of Singapore. However, like other animals harvested for the live aquarium trade, most die before they can reach the retailers. Without professional care, most die soon after they are sold. Those that do survive are unlikely to breed successfully. Like other creatures of the intertidal zone, they are affected by human activities such as reclamation and pollution. Trampling by careless visitors, and over-collection also have an impact on local populations. |
 Peacock anemones can be quite commonly seen on our Northern shores. Chek Jawa, Oct 03  The common peacock anemone is seen quite frequently on our Northern shores. Chek Jawa, Mar 05  An inner ring of shorter tentacles identifies this as a peacock anemone. Chek Jawa, Mar 05  Some common peacock anemones have variegated outer tentacles. Changi, Apr 04  Long body column that slips into an even longer tube. Changi, Jun 03  At low tide, bundles its tentacles together. Pasir Ris Park, Jul 08  Tiny black Phoronid worms are often seen with peacock anemones. |
They are animals and not plants!
Unlike other anemones, they have two types of tentacles:
long outer tentacles and short inner tentacles.
| Order
Ceriantharia recorded for Singapore from Wee Y.C. and Peter K. L. Ng. 1994. A First Look at Biodiversity in Singapore.
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Links
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Brooks/Cole of Thomson Learning Inc., 7th Edition. pp. 963 |
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