Broad
zoanthid
Palythoa mutuki
Family
Zonathidae
updated
Dec 2019
if you
learn only 3 things about them ...
They look like tiny sea anemones with long bodies.
Some may be highly toxic. Don't touch them!
They
are small and may retract at low tide. Don't step on them! |
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Where
seen? Like a cluster of little brown anemones, this animal is often seen
on many of our shores. On coral rubble and among seagrasses in large
seagrass meadows.
Features: Colonies generally 5-10cm,
each polyp about 1-2cm in diameter with a wide oral disk on a long
stout body column. This zoanthid incorporates sand in its body so
the body column feels rough to the touch. The wide oral disk has furrows
that radiate from the mouth to the edge of the disk. Sometimes with
one white furrow so the disk appears to have one split. Relatively
short tapered tentacles.
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Labrador, Jul
05 |
Oral disk
has furrows.
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Long body column that is
rough to the touch.
Labrador, Jun 08 |
The polyps are not embedded in a thick common tissue but are joined
to one another at the base by underground stems (called stolons).The
long body column raises the oral disk above the common tissue. Broad
zoanthids can multiply by budding. They are found in small clumps
of a few to many individuals. Body column usually beige or brown,
oral disk usually brown, sometimes shades of green or bright blue.
Some species of broad zoanthids have been recorded to contain the
highly toxic palytoxin.
Compared
to button zoanthids (Zoanthus sp.),
broad zoanthids are generally found in smaller clusters with fewer
individuals, although large mounds of them are sometimes seen.
Sometimes confused with sponges, ascidians and other
blob-like animals. Here's more on how
to tell apart blob-like animals.
What does it eat? Some species
are said to capture and eat large prey, rapidly enclosing and swallowing
them the way sea anemones do. But this has not been observed in our
zoanthids. |
At low tide with their tentacles retracted
they look like a clump of sausages.
Chek Jawa, Aug 05 |
Sisters Island,
Jul 06
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Kusu Island,
Mar 05
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Tuas, Aug 09
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Pulau Semakau,
Aug 11
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*Species
are difficult to positively identify without close examination.
On this website, they are grouped by external
features for convenience of display.
Broad
zoanthids on Singapore shores |
Other sightings on Singapore shores |
Pulau Pawai,
Dec 09 |
Pulau Sudong,
Dec 09 |
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Pulau Salu,
Jun 10 |
Pulau Salu,
Jun 10 |
Pulau Salu,
Aug 10 |
Pulau Salu,
Aug 10 |
Terumbu Berkas,
Jan 10 |
Pulau Berkas,
May 10 |
Pulau Senang,
Jun 10 |
Pulau Biola,
Dec 09 |
Pulau Biola,
Dec 09 |
Acknowlegement
With grateful thanks to Dr James Reimer of JAMSTEC (Japan Agency for
Marine-Earth Science and Technology) for identification of the zoanthids.
References
- Borneman,
Eric H. 2001. Aquarium
Corals: Selection, Husbandry and Natural History
T.F. H Publications. 464 pp
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