铜绿丽金龟对圆偏振光的行为和视网膜电位反应

圆偏振光在地球环境中是很少见的， 来自珠宝金龟甲体壁反射圆偏振光是稀有的自然资源之一。铜绿丽金龟Anomala corpulenta Motschulsky与其他珠宝金龟甲一样其体壁能够反射左旋圆偏振光。为了解铜绿丽金龟对圆偏振光的感知能力， 本研究利用室内行为、 田间诱集与视网膜电位(electroretinogram, ERG)等方法研究了铜绿丽金龟对圆偏振光的响应。室内行为研究结果表明， 铜绿丽金龟对左旋圆偏振光与右旋圆偏振光的趋光反应明显低于非偏振光， 避光反应明显大于非偏振光， 且对左旋圆偏振光的趋、 避光反应均大于右旋圆偏振光。田间选择试验结果显示， 铜绿丽金龟对左旋和右旋圆偏振光的选择明显低于非偏振光， 且右旋大于左旋圆偏振光。电生理学研究结果表明， 左旋和右旋圆偏振光与非偏振光一样， 均能引发铜绿丽金龟的ERG反应， 且无明显差异。这些研究结果表明铜绿丽金龟体壁能够反射产生左旋圆偏振光， 且能够感知和区分左旋和右旋圆偏振光， 说明铜绿丽金龟存在偏振视觉， 具有圆偏振光敏感性。

Behavioral and electroretinogram (ERG) responses of Anomala corpulenta (Coleoptera: Rutelidae) to circularly polarized light

Circularly polarized light is rare in the terrestrial environment, and cuticular reflection from scarab beetles is one of the few natural sources. The scarab beetle Anomala corpulenta Motschulsky possesses a brilliant metallic appearance, and selectively reflects left circularly polarized light as other jewel beetles. To clarify the capacity of responses of A. corpulenta to circularly polarized light, indoor behavior, field selection and electroretinogram (ERG) responses of A. corpulenta to circularly polarized light were studied in this experiment. The indoor behavior research showed that the phototaxis responses of A. corpulenta to left and right circularly polarized light were significantly lower than those to unpolarized light, while the photophobism responses were significantly greater than the phototaxis responses to unpolarized light, and both the phototaxis and photophobism responses of A. corpulenta to left circularly polarized were greater than those to right circularly polarized light. The field selection test results showed that the selection of A. corpulenta to left and right circularly polarized light was obviously lower than that to unpolarized light, and the responses selecting to right circularly polarized light were stronger than that to left circularly polarized light. Electrophysiological studies showed that left and right circularly polarized could trigger ERG responses of A. corpulenta compound eyes as unpolarized light, and had no obvious difference among them. These results indicate that A. corpulenta is a metallic iridescent species that selectively reflects left circularly polarized light and possesses a brilliant metallic appearance. It can perceive and distinguish left and right circularly polarized light, and circularly polarized light can trigger ERG responses of A. corpulenta compound eyes as unpolarized light. These results support the hypothesis that A. corpulenta has polarization vision and sensitivity to circularly polarized light.