2Author for correspondence: e-mail email@example.com.
MOVEMENT MODALITIES AND RESPONSES TO ENVIRONMENTAL CHANGES OF THE MUDFLAT DIATOM CYLINDROTHECA CLOSTERIUM (BACILLARIOPHYCEAE)1
Article first published online: 13 MAR 2006
Journal of Phycology
Volume 42, Issue 2, pages 379–390, April 2006
How to Cite
Apoya-Horton, M. D., Yin, L., Underwood, G. J. C. and Gretz, M. R. (2006), MOVEMENT MODALITIES AND RESPONSES TO ENVIRONMENTAL CHANGES OF THE MUDFLAT DIATOM CYLINDROTHECA CLOSTERIUM (BACILLARIOPHYCEAE). Journal of Phycology, 42: 379–390. doi: 10.1111/j.1529-8817.2006.00194.x
1Received 29 July 2005. Accepted 22 December 2005.
- Issue published online: 13 MAR 2006
- Article first published online: 13 MAR 2006
- corkscrew gliding;
- Cylindrotheca closterium;
- environmental effects;
- movement modality;
- video microscopy
Cylindrotheca closterium (Ehrenberg) Reiman et Lewin is a raphid diatom widely distributed in mudflat assemblages. Video microscopy showed various movement modalities defined as smooth and corkscrew gliding, pirouette, pivot, rock and roll, rollover, and simultaneous pirouette and gliding. Z-axis projection analysis of images revealed a unique gliding motif with corkscrew motions, which may have important ecological implications for C. closterium movement in muds. The general response to salinity alteration was a decrease in gliding movements with a concomitant increase in other modalities listed above. Short-term responses to salinity change include dramatic alteration in modalities in hypo-saline conditions and cessation of motility in extreme hyper-saline environments. Modality changes were rapid and occurred within 5 s in response to hyper-saline conditions. Hypo- or hyper-saline conditions resulted in decreased gliding speed in standard media. Five- and 15-day acclimation to salinity changes resulted in a progressive reduction in gliding movement, increased non-gliding modalities and increased cell aggregation. Aggregation in hypo-saline conditions was accompanied by a large increase in the polymer extracted by hot bicarbonate- and ethylenediamine tetraaceticacid- fractions of extracellular polymeric substance (EPS), the polymers of which have been implicated in cell attachment/motility phenomena. The monosaccharide profiles of these fractions were altered in response to hypo-saline conditions. In general, monosaccharide profiles showed increased diversity upon cessation of motility and aggregation of cultures. The movement responses of C. closterium in response to environmental changes, accompanied by modifications in EPS, may form part of an adaptive strategy to survive in mudflats and could be useful as bioindicators of environmental changes.