Visual capabilities in a crepuscular marsupial, the honey possum (Tarsipes rostratus):: a visual approach to ecology
Visual capabilities in a crepuscular marsupial, the honey possum (Tarsipes rostratus):: a visual approach to ecology
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DOI：
10.1017/s0952836902000183
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发表时间：
2002-02-01
影响因子：
2
通讯作者：
Beazley, LD
中科院分区：
文献类型：
--
作者：
Arrese, C;Archer, M;Beazley, LD
行为和解剖分析进行了确定视觉能力的小型负食澳大利亚有袋动物，蜜负鼠跗猴。有人提出，尽管蜜负鼠的生活方式是黄昏的，而且视力较低，但视觉对蜜负鼠对环境的感知有很大的影响。通过辨别任务确定的视敏度显示，在日光下的表现（0.63周期/度）略高于在月光和星光下的表现（0.60周期/度）。外视网膜的超微结构分析显示，视杆与视锥的比例与日间视网膜相当（中央视网膜20:1）。根据油滴的大小区分出两种油滴。神经收敛的程度也与白天的视网膜相似，12个光感受器：1个神经节细胞。出色的总视野，接近240度的视角，包括在水平面上80度的双目重叠，提供了有效的捕食者探测能力。讨论了蜂蜜负鼠的视觉能力与它的生活方式和相关的视觉要求。
Behavioural and anatomical analyses were undertaken to determine the visual capabilities of a small nectivorous Australian marsupial, the honey possum Tarsipes rostratus. It is proposed that, despite a crepuscular lifestyle and a low visual acuity, vision contributes substantially to the honey possum's perception of its environment. Visual acuity, determined using a discrimination task, revealed a slightly higher performance in daylight (0.63 cycles/degree) than in moonlight and starlight (0.60 cycles/degree). Ultrastructural analysis of the outer retina revealed a rod to cone ratio comparable to that found in diurnal retinae (20:1 in the central retina). Two types of oil droplets were distinguished on the basis of size. The degree of neural convergence was also similar to that found in a diurnal retina, with a ratio of 12 photoreceptors:1 ganglion cell. The remarkable total field of view, approaching 240degrees of visual angle and including a binocular overlap of 80degrees in the horizontal plane, provides an efficient predator detection capacity. The visual capabilities of the honey possum are discussed in relation to its lifestyle and the associated visual requirements.