NUTRIENTS DO NOT INFLUENCE SWIMMING BEHAVIOR OR SETTLEMENT RATES OF ECTOCARPUS SILICULOSUS (PHAEOPHYCEAE) SPORES |
| |
Authors: | Charles D Amsler Kisha L Shelton Christopher J Britton Netanya Y Spencer Stephen P Greer |
| |
Institution: | Department of Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294-1170 |
| |
Abstract: | Spores newly released from plurilocular sporangia of Ectocarpus siliculosus (Dillw.) Lyngb. sporophytes were assayed for chemotaxis to nutrients and for settlement stimulation by nutrients. To enable these measurements with relatively small volumes and numbers of released spores, we developed a computer-assisted motion-analysis assay for spore chemotaxis and verified the results with a more standard, capillary tube chemotaxis assay. The presence of a nutrient gradient did not influence the swimming behavior of E. siliculosus spores in the motion-analysis assay, and likewise no chemotactic effect was measured in the capillary tube assay. Microplate settlement assays previously utilized with bacteria and invertebrates were adapted for use with algal spores. E. siliculosus spores settled at higher rates on a hydrophobic plastic surface than on surfaces with either positively or negatively charged hydrophilic coatings. Nutrient mixtures had no effect on the rate of spore settlement on hydrophobic surfaces. |
| |
Keywords: | behavior chemotaxis dispersal Ectocarpus nutrients settlement spores |
|