Plasticity of the neural network in the compound eye of the Ligia exotica, Roux.

的眼睛Ligia新奇的原生类型的,rhabdoms开放。面是六角形的，屈光装置由一个平的角膜和一个放置在两个大锥细胞中心的球形晶体锥组成。每个小眼网膜有7个规则细胞和1个偏心细胞；基底膜形成视网膜的近端边界。当晶体尺寸从0.6 cm增加到接近4.0 cm（或更大）时，晶面数和圆径分别从800 μm增加到1500 μm和35 μm增加到100 μm；眼长和眼宽分别从1.2 mm和0.9 mm增加到3.2 mm和2.5 mm；屈光器的长度和视网膜层的宽度从70 μm变化到180 μm，从70 μm变化到120 μm左右。位于中心位置的小眼的视角和眼间角保持不变，分别为30°和6.9°左右。将眼长与眼眼直径的平方根之积作比较，发现眼长与眼眼数与眼眼直径之间存在着近乎完美的线性关系。男性和女性在任何关系中都没有观察到差异。小眼虫的数量是如何增加的？我们试着观察异叶橐吾复眼的边缘区域。为了描述不同眼区边缘小眼的特征，我们详细描述了三种不同大小类别Laxotica边缘小眼的不同超微结构特征。在横切面和纵切面的基础上，我们得出结论，新的小眼是从月牙形的眼背-内-腹缘加入的，成熟的小眼经过一个序列，在这个序列中，最初的视锥细胞、色素细胞和视网膜细胞的细胞核排列在三个独立的层中。在微绒毛发育开始时，相应横纹肌的组织结构与构成成熟横纹肌的横纹肌组织结构仍有很大不同。边缘小眼的直径总是小于位于中心的小眼，视网膜筛选色素颗粒只有在第一个微绒毛出现后才在视网膜细胞中最明显。为了了解裸眼数量增加后视觉色素的数量，我们用肟法测量了几种不同眼睛大小等级的Ligia的发色团数量。体型较小的动物（体型小于2厘米）只有40 pmol，而体型较大的动物（约3.5厘米）在它们的两个无柄眼睛中含有100 pmol。除了视角外，我们测量的所有值都随着体型的增加而增加。这些结果表明，所有标本基本上具有相同的视觉世界，因为较大的标本与较小的标本具有几乎相同的视角。少

The eye of Ligia exotica is of the apposition type and has open rhabdoms. The facets are hexagonal, and the dioptric apparatus consist of a flat cornea and a spherical crystalline cone placed in the canter of two large cone cells. Each ommatidium has seven regular retinula cells and one eccentric cell ; basement membrane forms the proximal boundary of the retina. With increases in body size from 0.6 cm to almost 4.0 cm (or some are more), facet numbers and ommatidial diameters increased from 800 to 1500 and 35 μm to 100 μm, respectively ; eye length and width grew from 1.2 to 3.2 and 0.9 to 2.5 mm, respectively ; and length of dioptric apparatus and width of retinal layer changed from 70 μm to 180 μm and about 70 μm to 120 μm. Visual angles and interommatidial angles of centrally located ommatidia remained constant at about 30 and 6.9 degrees, respectively. An almost perfect linear relationship was found when eye length was plotted against the product between the square root of the tot … More al number of ommatidia and the ommatuaal diameter. No diference between males and females was observed in any of the relationships.How does the number of the ommatidia increase? We tried to observe the marginal region of the compound eye of L. exotica. In order to characterize the marginal ommatidia from different eye regions, we made a detailed description of their distinct ultrastrtictural features in three different size-classes of Laxotica. On the bases of transverse as well as longitudinal sections we concluded that new ommatidia are added from a crescentic dorso-snterio-ventral edge of the eye and that maturing ommatidia go through a sequence in which originally the nuclei of cone-, pigment-, and retinula cells are arranged in three separate layers. At the beginning of the microvillar development, the organization of the corresponding rhabdomeres is still quite different from that of those rhabdomeres that make up the mature rhabdom. Marginal ommatidia always possess smaller diameters than more centrally located ones and retinal screening pigment granules are most apparent in the retinula cells only after the first micovilli have appeared.In order to know the amount of the visual pigments following the increase of the number of ommatidia, we measured the amount of chromophores using the several different eye size-classes of Ligia by the oxime method. The smaller animals (smaller than 2cm in body size) possessed only 40 pmol, whereas, the larger ones (ca.3.5 cm) possessed 100 pmol in their two sessile eyes.All of the value which we measure showed the increase following the increase of the body size, except the visual angle. Those results suggest that all specimens possess the same visual worlds basically because the larger specimens possess the almost same visual angles compared with the smaller ones. Less