updated Oct 2016
learn only 3 things about them ...
are often seen near cerianthids. They are shy and hide
at the slightest sign of danger. Be quiet and wait for
them to emerge.
They look like fanworms but belong to a different animal
tubes are made of chitin, the same substance that insect
exoskeleton is made of.
overshadowed by their more glamorous hosts, this tiny fluffy worm
is commonly seen with cerianthids
on our northern shores. Often several can be seen near one cerianthid.
Very shy, the worms retract at the slightest sign of danger. There's
a better chance of seeing them at night.
What are phoronid worms? Phoronid
worms are unsegmented worms belonging to
Phylum Phoronida. This is a small phylum with less than 20 species. They build and live inside tubes made of chitin.
Phoronis australis is thus far, the only phoronid known to
be encountered with cerianthids and it is found in all warm temperate
to tropical coasts from the intertidal to deeper waters.
Features: Phoronis australis
has a pair of feathery spiralling tentacles (diameter about 2cm).
The body is long, unsegemented and worm-like. Those seen on our shores
are grey or pinkish black, but elsewhere white ones are also seen.
Most phoronids build a tube that is made of chitin (the same substance
that insect skeletons are made of). More about tubeworms
Sometimes confused with
worms. Fan worms are segmented worms belonging to Phylum Annelida,
Class Polychaeta. More
on how to tell apart animals
with a ring of feathery tentacles.
According to Gosliner, the body of Phoronis australis penetrates
the tissues of the cerianthid but the phoronid worm is not parasitic
and does not absorb nutrients from the cerianthid directly.
What do they eat? Phoronids are
filter feeders, creating a current of water through their spiral of
tentatcles. Edible bits are trapped in mucus on the tentacles.
Phoronid babies: Some phoronids
can reproduce by budding or splitting into half. They also reproduce
by producing eggs and sperm. It is believed that the lifespan of phoronids
is only about one year. Phoronis australis is a hermaphrodite.
Phoroneus the hero: In Greek mythology,
Phoroneus is often said to be the son of a river god and ocean nymph.
He is credited for being the first to unite the Greeks as one people.
Previously, they had lived in scattered groups.
Changi, Jun 03
the white stuff eggs?
Changi, Aug 05
Changi, Aug 05
The anus is at the top of the body
in between the two 'fans'.
identification. Species are difficult to positively identify without close
On this website, they are grouped by external features for convenience of
phoronid worms on Singapore shores
Tuas, Mar 15
shared by Marcus Ng on facebook.
Pulau Semakau, Sep 09
shared by Loh Kok Sheng on flickr.
shared by Toh Chay Hoon on flickr.
With grateful thanks to Leslie H. Harris of the Natural
History Museum of Los Angeles County for comments on the identity
of this worm.
- Edward E.
Ruppert, Richard S. Fox, Robert D. Barnes. 2004.Invertebrate
Brooks/Cole of Thomson Learning Inc., 7th Edition. pp. 963
Jan A., 2005. Biology
of the Invertebrates.
5th edition. McGraw-Hill Book Co., Singapore. 578 pp.
- Morton, Brian
& John Morton, 1983. The
Sea Shore Ecology of Hong Kong.
Hong Kong University Press. 350 pp.
- Allen, Gerald
R and Roger Steene. 2002. Indo-Pacific
Coral Reef Field Guide.
Tropical Reef Research. 378pp.
- Humann, Paul
and Ned Deloach. 2010. Reef
Creature Identification: Tropical Pacific New World Publications.
- Kuiter, Rudie
H and Helmut Debelius. 2009. World
Atlas of Marine Fauna. IKAN-Unterwasserachiv. 723pp.
Terrence M., David W. Behrens and Gary C. Williams. 1996. Coral
Reef Animals of the Indo-Pacific: Animal life from Africa to Hawaii exclusive of the vertebrates
Sea Challengers. 314pp.