CONTENTS
Flora index
Fauna index
guide to the mangroves of singapore
Algae
Peter K L Ng and N Sivasothi (editors)
 

The algae are similar to the plants in that they can also photosynthesise but are usually single-celled organisms, or grow at best in small colonies, as a chain of cells (filament) or simple structures (thallus). They have life cycles as well as cell wall structures, carbohydrate reserves and pigments that are unlike those of the plants. Indeed, some have no cell walls. Only the larger species (macroalgae) will be treated here.

Brown Algae
Phylum Phaeophycota


Brown algae are an almost exclusively marine group. They are multicellular, often with complex anatomy and morphology. The photosynthetic pigments include chlorophylls a and c, xanthophylls and carotenes. Most occur in cooler regions.

Dictyota sp. (Class Phaeophyceae, Family Dictyotaceae) are found in most of the larger and less disturbed mangrove areas locally. The thallus consists of flattened dichotomously branching structures which often overlap each other. At the mid intertidal zone, on mangrove tree roots. Rare.

wide shot of algae
Thallus of Dictyota sp.

close-up
Close-up of thallus
of Dictyota sp.
Green Algae
Phylum Chlorophycota


Green algae possess the photosynthetic pigments chlorophylls a and b, alpha-, beta- or gamma-carotenes and xanthophylls. For storage, starch is the main product. Members have very similar metabolism to the plants and are considered by most to be their ancestors.

Chaetomorpha gracilis (Class Chlorophyceae, Family Cladophoraceae) France, Mediterranean, Jamaica. Locally, in most areas. Forms loose balls of filaments on mangrove roots, on mud or as a surface on mud balls, dirty dark green when wet and bright grass green when dry; the multi-nucleate cells are cylindrical, joined together as filaments which bear no rhizoids (root-hair like cells); cell walls are glass-like. No known economic value. Common. Previously known as Lola gracilis.

close-up
Numerous filaments of Chaetomorpha gracilis, resembling green glass wool

wide-shot of 'lawn' under mangrove trees
Green algae forms
a lawn-like surface
Red Algae
Phylum Rhodophycota


Red algae usually consist of filamentous forms but unlike the other algae, never possess flagella (a tiny, whip-like organelle for locomotion) at any stage of their life cycle. Their red colour is due to the pigment phycoerythrin, but they may be brown, black or purple owing to another pigment, phycocyanin.

A common species, Catenella sp. (Class Rhodophyceae, Family Rhabdoniaceae), has a dark reddish branching thallus which is constricted into segments (resembling a prickly pear cactus). It grows on muddy substrates and is sometimes eaten in the Orient, e.g. C. impudica in Myanmar.
magnified close up of branching thallus
Thallus of Catenelia sp.

wide shot of red algae 'carpet' below mangrove trees
Habitat of Catenelia sp.
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