Collin S P, Hoskins R V, Partridge J C
Department of Zoology, University of Western Australia, Nedlands, Australia.
Brain Behav Evol. 1997;50(6):335-57. doi: 10.1159/000113345.
The world's deep oceans are home to a number of teleosts with asymmetrical or tubular eyes. These immobile eyes possess large spherical lenses and subtend a large binocular visual field directed either dorsally or rostrally. Derived from a lateral non-tubular eye, the tubular eye is comprised of a thick main retina, subserving the rostrally or dorsally directed binocular visual field, and a thin accessory retina subserving, the lateral, monocular visual field. The main retina is thought to receive a focussed image, while the accessory retina is too close to the lens for a focussed image to be received. Several species also possess retinal diverticula, which are small evaginations of differentiated retina located in the rostrolateral wall of the eye and thought to increase the visual field. In order to investigate the spatial resolving power of these retinae (main, accessory and diverticulum), the distribution of cells within the ganglion cell layer was analysed from retinal wholemounts and sectioned material in ten species representing four genera. In all species, the main retina possesses a marked increase in cell density towards a specialised retinal region (area centralis), with a centro-peripheral gradient range between 7:1 and 60:1 and a peak density range of between 30 and 55 x 10(3) cells per mm2. The accessory retinae and the transitional zone between the main and accessory retinae possess relatively low cell densities (between 1 and 10 x 10(3) cells per mm2) and lack an area centralis. Retinal diverticula examined in four species possess mean ganglion cell densities of between 7.2 and 109.4 x 10(3) cells per mm2. Analyses of soma areas show that the ganglion cell layer of most species possesses cells with areas in a range of 8.0 to 15.4 microns2 in the main retina and between 15.1 and 17.4 microns2 in the accessory retina. The peak spatial resolving power of the main retina of the ten species varies from 4.1 to 9.1 cycles per degree. The positions of the retinal areae centrales relative to each species' binocular visual field are discussed in relation to what is known of feeding behaviour of these fishes in the deep-sea.
世界上的深海是许多具有不对称或管状眼睛的硬骨鱼的栖息地。这些不能活动的眼睛拥有大的球形晶状体，并具有一个朝背部或吻部方向的大双眼视野。管状眼由侧向非管状眼演化而来，它由一个厚的主视网膜和一个薄的附属视网膜组成，主视网膜用于服务朝吻部或背部方向的双眼视野，附属视网膜用于服务侧向的单眼视野。主视网膜被认为能接收聚焦图像，而附属视网膜离晶状体太近，无法接收聚焦图像。有几个物种还拥有视网膜憩室，它是位于眼吻侧壁的分化视网膜的小突起，被认为能扩大视野。为了研究这些视网膜（主视网膜、附属视网膜和憩室）的空间分辨能力，我们分析了代表四个属的十个物种的视网膜整体标本和切片材料中神经节细胞层内的细胞分布。在所有物种中，主视网膜朝着一个特化的视网膜区域（中央区）细胞密度显著增加，中心 - 外周梯度范围在7:1到60:1之间，峰值密度范围在每平方毫米30到55×10³个细胞之间。附属视网膜以及主视网膜和附属视网膜之间的过渡区细胞密度相对较低（每平方毫米1到10×10³个细胞之间），且没有中央区。在四个物种中检查的视网膜憩室，其神经节细胞平均密度在每平方毫米7.2到109.4×10³个细胞之间。对细胞体面积的分析表明，大多数物种的神经节细胞层在主视网膜中细胞面积范围为8.0到15.4微米²，在附属视网膜中为15.1到17.4微米²。这十个物种主视网膜的峰值空间分辨能力在每度4.1到9.1周期间变化。结合已知的这些鱼类在深海中的摄食行为，讨论了视网膜中央区相对于每个物种双眼视野的位置。
