Champ Connor, Wallis Guy, Vorobyev Misha, Siebeck Ulrike, Marshall Justin
Queensland Brain Institute, The University of Queensland, Brisbane, Qld., Australia.
Brain Behav Evol. 2014;83(1):31-42. doi: 10.1159/000356977. Epub 2014 Jan 3.
Coral reef fish present the human observer with an array of bold and contrasting patterns; however, the ability of such fish to perceive these patterns is largely unexamined. To understand this, the visual acuity of these animals - the degree to which they can resolve fine detail - must be ascertained. Behavioural studies are few in number and anatomical analysis has largely focused on estimates of ganglion cell density to predict the visual acuity in coral reef fish. Here, we report visual acuity measures for the triggerfish Rhinecanthus aculeatus. Acuity was first assessed using a series of behavioural paradigms and the figures were then contrasted with those obtained anatomically, based on photoreceptor and ganglion cell counts. Behavioural testing indicated an upper behavioural acuity of 1.75 cycles·degree(-1), which is approximately the same level of acuity as that of the goldfish (Carassiusauratus). Anatomical estimates were then calculated from wholemount analysis of the photoreceptor layer and Nissl staining of cells within the ganglion cell layer. Both of these anatomical measures gave estimates that were substantially larger (7.75 and 3.4 cycles·degree(-1) for the photoreceptor cells and ganglion cells, respectively) than the level of acuity indicated by the behavioural tests. This indicates that in this teleost species spatial resolution is poor compared to humans (30-70 cycles·degree(-1)) and it is also not well indicated by anatomical estimates.
珊瑚礁鱼类呈现给人类观察者一系列醒目的、对比鲜明的图案；然而，这类鱼感知这些图案的能力在很大程度上尚未得到研究。为了弄清楚这一点，必须确定这些动物的视敏度——即它们分辨精细细节的程度。行为学研究数量很少，解剖学分析主要集中在通过估计神经节细胞密度来预测珊瑚礁鱼类的视敏度。在此，我们报告了尖吻鲀（Rhinecanthus aculeatus）的视敏度测量结果。首先使用一系列行为范式评估视敏度，然后将这些数据与基于光感受器和神经节细胞计数通过解剖学方法获得的数据进行对比。行为测试表明其行为视敏度上限为1.75周/度，这与金鱼（Carassius auratus）的视敏度水平大致相同。然后通过对视感受器层的整装分析和神经节细胞层内细胞的尼氏染色来计算解剖学估计值。这两种解剖学测量方法得出的估计值（光感受器细胞和神经节细胞分别为7.75周/度和3.4周/度）都比行为测试所表明的视敏度水平高得多。这表明在这种硬骨鱼物种中，与人类（30 - 70周/度）相比，空间分辨率较差，而且解剖学估计值也不能很好地表明这一点。
