van der Meer H J, Bowmaker J K
Department of Organismal Zoology, University of Leiden, The Netherlands.
Brain Behav Evol. 1995;45(4):232-40. doi: 10.1159/000113552.
The photoreceptors of four co-existing haplochromine cichlids have been studied morphometrically and microspectrophotometrically, and the results were interpreted in terms of resolution and sensitivity. Among the three species, Haplochromis argens, H. piceatus and H. ishmaeli, the cone dimensions and the visual pigments differed only slightly, in spite of differences in vertical distribution and feeding behaviour between these species. The fourth species H. pyrrhocephalus showed distinctly different visual properties, with very large double cones at low densities, and its spectral sensitivity shifted to significantly longer wavelengths. To some degree, the photoreceptor morphometrics and visual pigments appeared to be attuned to the photic conditions of the specific habitats. The two species H. piceatus and H. pyrrhocephalus, occupying a dimmer habitat with less penetrating blue light, had reduced blue sensitive single cones, whereas the surface dwelling species H. argens had relatively small red/green sensitive double cones. Also an attempt has been made to relate the visual capacity of the cichlids to their behavioural patterns, focussing on prey detection. The greatest visual differences were observed in the two species H. argens and H. pyrrhocephalus, with resources coincidence and with the highest encounter frequency, which may indicate that visual segregation contributes towards reducing interference competition among co-existing species with a similar diet.
对四种共存的朴丽鱼属丽鱼科鱼类的光感受器进行了形态测量和显微分光光度测定，并根据分辨率和灵敏度对结果进行了解释。在这三个物种中，即银朴丽鱼、皮氏朴丽鱼和伊斯梅尔朴丽鱼，尽管它们在垂直分布和摄食行为上存在差异，但视锥尺寸和视觉色素仅有轻微不同。第四个物种红顶朴丽鱼表现出明显不同的视觉特性，其双视锥很大但密度较低，并且其光谱灵敏度向明显更长的波长偏移。在某种程度上，光感受器形态测量和视觉色素似乎与特定栖息地的光照条件相适应。皮氏朴丽鱼和红顶朴丽鱼这两个物种占据了较暗的栖息地，蓝光穿透较少，它们对蓝光敏感的单视锥减少，而栖息在水面的银朴丽鱼具有相对较小的对红/绿敏感的双视锥。此外，还尝试将丽鱼科鱼类的视觉能力与其行为模式联系起来，重点关注猎物检测。在银朴丽鱼和红顶朴丽鱼这两个物种中观察到最大的视觉差异，它们资源重合且相遇频率最高，这可能表明视觉隔离有助于减少具有相似食性的共存物种之间的干扰竞争。
