Rhiel E, Hader D P, Wehrmeyer W
Fachbereich Biologie-Botanik, Karl-von-Frisch-Str., Federal Republic of Germany.
Plant Cell Physiol. 1988 Jul;29(5):755-60.
Phototaxis and gravitaxis are characterized in a freshwater species of the flagellate Cryptomonas. The phototactic orientation in this limnetic species is unusual and differs from all other Cryptomonas species studied so far: At both low (< or = 1O W m-2) and higher fluence rates it orients perpendicular to the light beam (diaphototaxis) while another freshwater Cryptomonas species (strain CR-1) is restricted to positive phototaxis and the marine species, C. maculata, shows both a positive and a more pronounced negative phototaxis. The mechanism of light direction detection seems to depend on a periodic shading or irradiation mechanism as confirmed by the disturbance of phototaxis in the presence of high viscosity media. In addition, this freshwater species possesses a rather pronounced negative gravitaxis which is only partially modified by phototaxis. The ecological consequences of this behavior are discussed.
对一种淡水鞭毛虫隐滴虫属物种的趋光性和趋地性进行了研究。这种淡水物种的趋光性取向不同寻常，与迄今研究的所有其他隐滴虫属物种都不同：在低（≤10 W m-2）和较高光通量率下，它都垂直于光束定向（横向趋光性），而另一种淡水隐滴虫属物种（CR-1菌株）仅表现为正向趋光性，海洋物种黄斑隐滴虫则同时表现出正向趋光性和更明显的负向趋光性。光方向检测机制似乎取决于周期性遮光或照射机制，这在高粘度介质存在下趋光性受到干扰时得到了证实。此外，这种淡水物种具有相当明显的负向趋地性，仅部分受趋光性影响。文中讨论了这种行为的生态后果。
