Diatom, Gomphonema
This is from a mat of dead Cladophora algae removed from the Columbia River in northern
Washington State. The Cladophora can be seen in the background.
Transmitted Phase Contrast Illumination
Definition/Function:
Gomphonema is a form of algae that can produce a undesirable slime in water. It is also used as an indicator
of industrial wastes and sewage in water (see ALGAE AND WATER POLLUTION by the US Environmental Protection Agency). A
description of Gomphonema is given in THE FRESHWATER ALGAE by G. W. Prescott in the "HOW TO KNOW" series.
Significance in the Environment:
Its presence in a fresh water stream or river can indicate industial or sewage pollution.
Characteristic Features:
Gomphonema is transversely unsymmetrical. There is a bulb at each end with an enlarged midregion. The striae are
relatively coarse.
Associated Particles:
References:
Prescott, G. W., HOW TO KNOW THE FRESHWATER ALGAE, Wm. C. Brown Company, p. 308, 1970
U.S. EPA, ALGAE AND WATER POLLUTION, EPA-600/9-77-036, p. 43, Plate II, 1977.
Vinyard, William C., DIATOMS OF NORTH AMERICA, Mad River Press, Inc., p.62, 1979. (ISBN 0-916-422-15-1)
Round, F.E., R. M. Crawford, D.G. Mann, THE DIATOMS:BIOLOGY & MORPHOLOGY OF THE GENERA, Cambridge University Press, pp.
148-9, 1990. (ISBN 978-0-521-71469-3)
Stoermer, Eugene F. and John P. Smol (eds), THE DIATOMS:APPLICATIONS FOR THE ENVIRONMENTAL AND EARTH SCIENCES, Cambridge
University Press, 2001 (ISBN 0521004128)