Nilsson D E, Odselius R, Elofsson R
Cell Tissue Res. 1983;230(2):401-10. doi: 10.1007/BF00213813.
Each of the approximately 500 ommatidia in the compound eye of the cladoceran crustacean Leptodora kindtii has a crystalline cone consisting of five cells. Five retinula cells are also present, one of which contributes to the distal 1-2 micrometer of the rhabdom only; the other four retinula cells from a continuous rhabdom. Throughout the rhabdom its cross section displays two separate halves with the axis of the microvilli in one half perpendicular to that in the other (orthogonal pattern). Interferometric analysis of the refractive index of the crystalline cone revealed an inhomogeneous system with one distal and one proximal gradient. The gradient system was found to exclude rays entering from adjacent facets, thus maintaining the optical isolation. Consequently, these optics replace distal screening pigment, which is absent in the eye. The long and unscreened crystalline cones give rise to an almost transparent eye in conformity with the overall transparency of this plank-tonic animal. The morphological characteristics of the eye of this species deviate from other cladoceran eyes, but the optical design closely resembles that of some pelagic marine amphipod crustaceans.
枝角类甲壳动物金氏薄皮溞复眼中大约500个小眼，每个小眼都有一个由五个细胞组成的晶锥。也存在五个视小杆细胞，其中一个仅对视杆远端1 - 2微米有贡献；其他四个视小杆细胞形成一个连续的视杆。在整个视杆中，其横截面显示出两个分开的部分，其中一半微绒毛的轴与另一半垂直（正交模式）。对晶锥折射率的干涉测量分析揭示了一个不均匀系统，有一个远端梯度和一个近端梯度。发现该梯度系统可排除从相邻小眼面进入的光线，从而保持光学隔离。因此，这些光学结构替代了眼睛中不存在的远端屏蔽色素。长且无屏蔽的晶锥使得眼睛几乎透明，这与这种浮游动物的整体透明度一致。该物种眼睛的形态特征与其他枝角类动物的眼睛不同，但其光学设计与一些远洋海洋双足甲壳类动物的眼睛非常相似。
