Ultrastructural observations on the marine fouling diatomAmphora

Abstract

Ecological and Scanning electron microscope (S. E. M.) studies indicated that the diatom Amphora was an important constituent in the initial colonization of test panels coated with a copper antifouling composition. Amphora was also found as the dominant fouling diatom species on paint samples from "in-service" supertankers and yachts. Associated with the diatom was copious amounts of mucilaginous material, which often encapsulated the cells. Histochemical analysis of the mucilage indicates that it is predominantly polysaccharide in nature. Using the Transmission electron microscope (T. E. M.) and electron microscope cytochemistry the intracellular origin of the adhesive was investigated. T. E. M. and S. E. M. observations of acid-cleaned-cells indicate that the mucilage may be secreted through specialized regions of the frustule. Material isolated from antifouling panels was compared with laboratory cultured Amphora spp. for copper resistance and internal accumulation using TEMSCAN -X ray analytical equipment.

Influence of initial substratum surface tension on marine micro- and macro-fouling in the Gulf of Thailand

“…Diatom glues are predominantly composed of polysaccharides (Chamberlain, 1976;Daniel et al, 1980;Cooksey & Cooksey, 1986;Hoagland et al, 1993), but it has been shown that proteinous material is involved in attachment processes as well (Webster et al, 1985). Like bacteria, diatoms are able to sense different surface conditions (Wigglesworth-Cooksey & Cooksey, 1992).…”

Cytochemical and electron microscopical observations on the adhesive materials of marine fouling diatoms

“…Methods of preparation were similar to those described in Daniel et al (1980). Final examination took place in a Jeol 100B TEM using an accelerating voltage of 80 kV or a Jeol T20 SEM.…”

“…was given in Daniel et al (1980). A complementary series of cytochemical tests have been applied during this study to two further species of Amphora, A. coffeaeformis (Ag.)…”

“…This is important both ecologically (Round, 1971) and economically where the diatoms constitute at least part of a community of fouling organisms (Callow, Evans & Christie, 1976;Daniel, Chamberlain & Jones, 1980;Daniel & Chamberlain, 1981;Terry & Edyvean, 1981;Edyvean & Terry, 1983). Attachment is invariably associated with the extracellular secretion of mucilaginous substances which may either remain as a simple layer interposed between the diatom and its substrate or, through continued secretion, develop into one of several morphologically distinct structures.…”

“…However, stains of known specificity have only been utilized on fouling, benthic diatoms within the last 10 years. A limited cytochemical investigation was conducted by Chamberlain (1976) but more recently, Daniel et al (1980) and Blunn & Evans (1981) have used a wider range of specific cytochemical reactions in studies of Amphora and Achnanthes subsessilis Kfitzing, respec-tively. Cytochemistry has also been used to distinguish between internal components of the diatom cell envelope (Crawford, 1973;Schnepf & Drebes, 1977;Stosch & Reimann, 1976;Daniel, 1983).…”