Differences in swimming pattern between life cycle stages of the toxic dinoflagellate Alexandrium fundyense

• Published in: Harmful algae 2013-01, Vol.21-22, p.36-43
• Main Authors: Persson, Agneta, Smith, Barry C., Wikfors, Gary H., Alix, Jennifer H.
• Format: Article
• Language: English
• Subjects: Alexandrium; Alexandrium fundyense; Algae; Animal and plant ecology; Animal, plant and microbial ecology; Autoecology; Behavior; Biological and medical sciences; Bloom; computer software; culture media; developmental stages; Dinoflagellate; Earth and Related Environmental Sciences; encystment; Fundamental and applied biological sciences. Psychology; Gamete; Geovetenskap och miljövetenskap; germ cells; marine sediments; Mating; Motion; Plant cytology, morphology, systematics, chorology and evolution; Plants and fungi; Swimming; Thallophyta; toxicity; vegetative cells; Zygote
• ISSN: 1568-9883; 1878-1470
• DOI: 10.1016/j.hal.2012.11.005

► Quantitative measures of motility patterns of different life stages of Alexandrium fundyense. ► Gamete swimming behavior is optimized for achieving cell contact and fusion. ► Gamete behavior is induced in encystment medium also without a compatible strain. ► Zygotes swim slowly but continue to contact cells and other surfaces. Different life stages of Alexandrium fundyense have different swimming behavior; gametes often are said to “swarm” or “dance” before mating. This behavior was studied, and quantitative measures of these motility patterns in two-dimensions were generated using motion-analysis software applied to video records of individual-cell movements. Behavior, swimming patterns, and growth were studied in two strains of A. fundyense and compared in encystment medium and growth medium. Vegetative cells swam straight, rotating around the apical axis until they hit something and then swam straight in a different direction. Gamete swimming behavior was slower and characterized by frequent direction changes and circular motion. Gametes contacted other cells frequently (>5cellcontactsmin−1cell−1). Zygotes swam slowly when newly formed and later became nearly immobile; these cells continued to contact other cells and also surfaces. The results are in accordance with field observations of long swimming distances for vegetative cells, accumulation in thin layers of gametes, and sinking of developing resting cysts attached to marine snow for zygotes.