Spike Walker (2011) CIL:38808, Dytiscus marginalis. CIL. Dataset

This polarized photomicrograph shows the rows of suckers on the foreleg of a male Dytiscus marginalis, commonly known as the great diving beetle - the largest freshwater beetle in the UK. It has a large streamlined body that is dark brown in color, with a yellow abdomen and yellow legs. Great diving beetles spend the majority of their time underwater hunting for food, feeding on other insects, tadpoles and small fish. They also mate underwater, and to aid this, the males have developed plate-like proximal tarsal joints on their front legs, which are covered in suckers. These suckers allow the male to hold onto a female during mating. This image shows a portion of such a joint, detailing part of one of the two larger suckers and five rows of small ones. The vibrant colors were achieved by passing light through colored filters onto the specimen, a technique known as Rheinberg illumination.

此偏振光显微照片展示了雄性 Dytiscus marginalis（俗名：大潜水甲虫，英国最大的淡水甲虫）前腿上的吸盘排列。大潜水甲虫体型庞大，流线型，呈深棕色，腹部及腿部为黄色。此类甲虫大多数时间在水下觅食，以其他昆虫、蝌蚪及小鱼为食。它们亦在水下交配，为此，雄性甲虫在前腿上进化出了类似平板的近端跗节关节，其表面布满吸盘，有助于在交配过程中抓握雌性。该图像展示了一个此类关节的部分，详细描绘了两个较大吸盘之一的部分及五排较小的吸盘。通过将彩色滤光片之光透过标本，实现了鲜艳的色彩效果，此技术被称为莱茵贝格照明。