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Index of flora
Index of fauna
Kingdom Animale | Phylum Arthropoda | Subphylum Crustacea | Class Cirripedia
 
Photo by Kang Nee
Acorn Barnacle
Balanus
Barnacles

These common littoral animals are actually highly modified crustaceans, not molluscs or shells.

In fact, the main ingredient of the popular fried oyster dish, "Oh Luak" or "Oh Chien" has sometimes been incorrectly attributed to barnacles instead of oysters.
The mature free-swimming larvae, which resemble mussel shrimps, attach onto rocks head first, glueing themselves by means of a strong protein cement, and forming calcareous plates around themselves. During high tide their modified legs protrude to catch planktonic life forms.

They are important as fouling organisms, their presence often serious enough to considerably slow ships down. Scraping them off is an expensive and laborious task. Recently, barnacles have become important in dentistry since their strong protein cement has been found to be useful in fitting dentures.

The flat and small Chthamalus, the star barnacle (Family Chthalmalidae), occupies the highest tide levels while the volcano barnacle, Tetraclita (Family Balanidae) is the largest, its lateral valves being indistinct. They are more common in open areas, in the upper parts of the littoral zone. The less common stalked goose barnacles (Family Lepidae) are sometimes seen on driftwood or flotsam.


Tetraclita

Photo by Kang Nee
Chthamalus

Photo by Johari
Balanus
on pneumatophore
Barnacles also attach themselves to other animals like crabs.
Some barnacles have become tiny parasites.
Introduction
Shore environment
 
From A Guide to Seashore Life by Dr Leo W H Tan and Peter K L Ng
Published by the Singapore Science Centre and sponsored by BP

@Raffles Museum of Biodiversity Research and Singapore Science Centre