Department of Biological Sciences, Wright State University, Dayton, Ohio 45435.
Mycologia. 2004 May-Jun;96(3):463-9.
Ulkenia sp. zoospores are attracted to 492 nm wavelength light produced by the marine bacterium Vibrio fischeri. Zoospores are positively photoresponsive to wavelengths of 440, 460 and 480 nm and contain a pigment that absorbs blue light. The average velocity of the zoospores is 0.47 m h(-1). Stimulatory intensities of these wavelengths ranged from 0.5 to 3.5 μEm(-2) s(-1) in both laboratory and field studies. The response of this protist to bioluminescence produced by Vibrio fischeri may direct zoospores to a nutrient rich environment colonized by these bacteria. In addition, the greatest responses were found at intensities associated with the light regime found near the bottom of naturally turbid estuaries or at greater depths of nonturbid, offshore waters. Positive phototaxis was not seen in zones of high light intensity either in field or laboratory studies, and there is some indication that zoospores may swim away from high light intensities.
Ulkenia sp. 游动孢子被海洋细菌 Vibrio fischeri 产生的 492nm 波长的光吸引。游动孢子对 440、460 和 480nm 波长的光具有正光响应性，并且含有吸收蓝光的色素。游动孢子的平均速度为 0.47 m h(-1)。在实验室和野外研究中，这些波长的刺激强度范围在 0.5 到 3.5 μEm(-2) s(-1)之间。这种原生动物对 Vibrio fischeri 产生的生物发光的反应可能会引导游动孢子进入这些细菌定植的营养丰富的环境。此外，在自然浑浊河口底部或非浑浊、近海水域较深的地方发现的与光照条件相关的强度下，产生了最大的反应。在野外或实验室研究中，都没有观察到强光区的正趋光性，并且有一些迹象表明游动孢子可能会远离强光强度。
