Compound Eye Adaptations for Diurnal and Nocturnal Lifestyle in the Intertidal Ant, Polyrhachis sokolova
Compound Eye Adaptations for Diurnal and Nocturnal Lifestyle in the Intertidal Ant, Polyrhachis sokolova
复制标题
潮间带多刺蚁的复眼对昼夜生活方式的适应
作者：
A. Narendra;A. Alkaladi;C. A. Raderschall;S. Robson;W. Ribi
澳大利亚潮间带蚂蚁，Polyrhachis sokolova生活在泥滩栖息地，并在红树林底部筑巢。它们是依靠视觉线索的独居觅食蚂蚁。蚂蚁在白天和晚上的低潮期间都很活跃，因此会经历各种各样的光照强度。我们在这里问在何种程度上的复眼P. sokolova反映的事实，他们在白天和黑夜的运作。复眼为典型的并列复眼，每眼有596个小眼，小眼内角为6.0°。我们发现蚂蚁已经发展出大的晶状体（直径33微米）和宽的横纹（直径5微米），使它们的眼睛对弱光条件高度敏感。为了在明亮的光线条件下保持活跃，蚂蚁已经发展出一种极端的瞳孔机制，在此过程中，初级色素细胞收缩晶体锥，形成一个0.5微米宽，16微米长的狭窄通道。这种瞳孔机制保护光感受器免受明亮光线的影响，使眼睛在白天不那么敏感。复眼的背缘区域有专门的感光器，可以帮助检测偏振天窗模式的方向，这将有助于动物确定在巢穴和食物来源之间导航时所需的罗盘方向。
The Australian intertidal ant, Polyrhachis sokolova lives in mudflat habitats and nests at the base of mangroves. They are solitary foraging ants that rely on visual cues. The ants are active during low tides at both day and night and thus experience a wide range of light intensities. We here ask the extent to which the compound eyes of P. sokolova reflect the fact that they operate during both day and night. The ants have typical apposition compound eyes with 596 ommatidia per eye and an interommatidial angle of 6.0°. We find the ants have developed large lenses (33 µm in diameter) and wide rhabdoms (5 µm in diameter) to make their eyes highly sensitive to low light conditions. To be active at bright light conditions, the ants have developed an extreme pupillary mechanism during which the primary pigment cells constrict the crystalline cone to form a narrow tract of 0.5 µm wide and 16 µm long. This pupillary mechanism protects the photoreceptors from bright light, making the eyes less sensitive during the day. The dorsal rim area of their compound eye has specialised photoreceptors that could aid in detecting the orientation of the pattern of polarised skylight, which would assist the animals to determine compass directions required while navigating between nest and food sources.