Home / Diatoms / Pennate / Colonies / Gomphonema
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Name derivation:
"Thread of clubs" -- club (-gompho) thread (-nema)
Classification:
Gomphonema Ehrenberg 1832; 307 of 1317 species descriptions are currently accepted taxonomically (Guiry and Guiry 2014). Order Cymbellales; Family Gomphonemataceae
Morphology:
Colonial cells that form on branched muscilage stalks that are attached to a subtrate. In girdle view the cells are wedge shaped with a an enlarged head at the opposite end of the stalk. Cells have one large plastid that lye mostly on one side of the girdle, but does extend partially onto the other side. Contains one central pyrenoid.
Similar genera:
Didymosphenia is similiar, but is larger than Gonphonema. Rhoicosphenia is also similiar, but has a definite bend mid-center of each cell.
Pheromone production:
The fresh water diatom Gomphonema parvulum (Bacillariophyceae) produces the algal pheromones hormosirene 2 (C11H16) and dictyopterene A 16 (C11H18) from highly unsaturated eicosanoic acids like 20:5 (ω−3) 21 and 20:4 (ω−6) 14. Pheromones used as a method of signaling to other freshwater diatoms (Pohnert and Boland, 1996)
Habitat:
Common in freshwater attached to the benthos. Gomphonema parvulum (Kützing) and Navicula cryptocephala (Kützing) were found in higher abundances in more humic streams (Kahlert and Gottschalk, 2014)
References:
Guiry, M.D. and G.M. Guiry 2014. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 30 May 2014. Round, F. E., Crawford, R. M., Mann, D. G. 1990. The Diatoms. Cambridge University Press. New York, NY. Pohnert, G. and W. Boland 1996. Biosynthesis of the algal pheromone hormosirene by the fresh-water diatom Gomphonema parvulum (Bacillariophyceae). Tetrahedron. 52(30):10073–10082. Kahlert, M. and S. Gottschalk 2014. Differences in benthic diatom assemblages between streams and lakes in Sweden and implications for ecological assessment. Freshwater Science 33(2):655-669. University of Chicago Press. http://www.jstor.org/stable/10.1086/675727.