Hydroides elegans (Haswell) were common bio-foulers in Hong Kong waters. S. spirorbis and D.furaminosa were pioneers of bio-fouling communities and would be overwhelmed by other bio-foulers at later stage, such as H. elegans. In Hong Kong, the maximum recorded wet weight of H. elegans on submerged marine installations was 20.34kg/m². Although the worms were abundant in bio-fouling communities from tropical to temperate zones and was popular in the studies of bio-fouling organisms, the chemistry and ultrastructure of the calcareous tubes are still unknown. The objectives of this study were to identify and quantify the inorganic and organic tube components; and to examine the fine structure of the tubes. The inorganic tube components were identified by infra-red spectroscopy, X-ray diffra...[ Read more ]

Hydroides elegans (Haswell) were common bio-foulers in Hong Kong waters. S. spirorbis and D.furaminosa were pioneers of bio-fouling communities and would be overwhelmed by other bio-foulers at later stage, such as H. elegans. In Hong Kong, the maximum recorded wet weight of H. elegans on submerged marine installations was 20.34kg/m². Although the worms were abundant in bio-fouling communities from tropical to temperate zones and was popular in the studies of bio-fouling organisms, the chemistry and ultrastructure of the calcareous tubes are still unknown. The objectives of this study were to identify and quantify the inorganic and organic tube components; and to examine the fine structure of the tubes. The inorganic tube components were identified by infra-red spectroscopy, X-ray diffraction and microanalysis with transmission electron microscopy. Relative amount of different crystalline forms and the ratio of calcium to magnesium ions in the tubes were calculated. The insoluble organic matrix was identified and quantified by infra-red spectroscopy, spectrophotometric methods, CHN elemental analysis and microanalysis with scanning electron microscopy. It was a heterogeneous assemblage of polysaccharide, protein and lipid. Preliminary evidence was found to prove the organic matrix of H. elegans tube was the adhesive material for substratum attachment. Fine structures of both inorganic and organic tube components were examined by scanning electron microscopy on different surfaces of calcareous tube and decalcified tube. Architectural heterogeneity in the crystallites was observed in the tubes of all three species. The insoluble organic matrix was revealed to be a mesh-like material for binding the crystallites together; and was revealed to be a sheet-like material for crystal growth.