CONTENTS
Flora index
Fauna index
guide to the mangroves of singapore
Crustacea
Peter K L Ng and N Sivasothi (editors)
  Barnacles
Barnacles are found in the more marine conditions of the mangrove, and occur in large numbers. The free-swimming larvae in the water attach themselves head-first to almost any surface (including hard-bodied/shelled animals), glue themselves with a strong cement, form calcareous plates around them and then feed by sticking out feathery legs to catch plankton when the tide rises!

Ships use extra fuel just to overcome the drag caused by accumulations of these animals on hulls (also called fouling). Combatting this problem is in fact a multi-million dollar industry for marine paint countries. Usage of heavy metal paints and synthetic compounds cause damage to the environment and it is hoped that a natural compound can be isolated from some animals which appear never to get settled on.
close-up of barnacles feeding in water
Balanus feeding
in water

close-up of barnacles out of water
Euraphia withersi
on a tree trunk
zonation of barnacles Zonation of barnacles
on a mangrove
tree trunk:
Euraphia forms a
distinctive zone
above Balanus
 On tree trunks, you will see a classic case of zonation. The lower and wetter parts of a tree trunk are inundated more frequently by the sea, and it gets drier up the tree until you reach the driest parts only splashed every two weeks by a spring tide.

In competition for space and thus feeding area, zonation occurs:
a cluster of barnacles on a tree trunk
Barnacle clusters often
consist of both dead
and living individuals
The larger Acorn barnacles (Balanus sp., Family Balanidae) are found on the lower, wetter parts of the tree. The smaller Star barnacles (Euraphia sp. formerly Chthamalus sp. Family Chthamalidae) are forced to survive by adapting to the less favourable drier zones further up the tree which Balanus is as yet unable to colonise.

<<Back to crustacea
What is mangrove?
Introduction

The Ecosystem
Abiotic
Biotic

Value
Intro
Products
Indirect uses
Potential uses

About Mangroves
in Singapore
History
Mangroves to visit
Conservation
 
From "A Guide to Mangroves of Singapore", Peter K. L. Ng and N. Sivasothi (editors)
Volume 1: The Ecosystem and Plant Diversity and Volume 2: Animal Diversity
Authors: Kelvin K. P. Lim, Dennis H. Murphy, T. Morgany, N. Sivasothi, Peter K. L. Ng,
B. C. Soong, Hugh T. W. Tan, K. S. Tan & T. K. Tan
BP Guide to Nature Series published by the Singapore Science Centre, sponsored by British Petroleum
© 2001 Raffles Museum of Biodiversity Research, The National University of Singapore & The Singapore Science Centre