Ear and eye in subterranean mole-rats, Fukomys anselli (Bathyergidae) and Spalax ehrenbergi (Spalacidae):: progressive specialisation or regressive degeneration?
Ear and eye in subterranean mole-rats, Fukomys anselli (Bathyergidae) and Spalax ehrenbergi (Spalacidae):: progressive specialisation or regressive degeneration?
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DOI：
10.1163/157075606778967847
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发表时间：
2006-12-01
期刊：
影响因子：
1.2
通讯作者：
Burda, Hynek
中科院分区：
文献类型：
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作者：
Burda, Hynek
鼹鼠，Spalax ehrenbergi（Spalacidae）从以色列和Ansomys（原Cryptomys）anselli（Bathyergidae）从赞比亚，两个啮齿动物类群，独立地适应地下生活的听觉和视觉生态，进行了审查和比较epigeic同行，实验室大鼠和豚鼠。在洞穴中，低频（200-800 Hz）的空气传播声音衰减最小，甚至在短距离内加重。在这两种鼹鼠中，最佳听力的频率范围被转移到与隧道中最佳传播的频率相匹配：在较低频率范围（< 16 kHz）的听力灵敏度被保存或进一步提高。与大鼠相比，鼹鼠的听力范围（覆盖约8个倍频程）并不受限制，而只是向较低的频率移动。鼹鼠和豚鼠的中耳和内耳的形态在某些方面相似，并表明调谐到低频。鼹鼠的中车形态似乎不能解释听力的高频下限。中耳未缩小或退化。相反，砧骨和镫骨足板明显增大，导致敏感性降低。这些特征可以被认为是一种适应，以补偿当地的声音放大洞穴。耳蜗及其组成部分是高度专业化的敏感感知和低频率的高分辨率。尽管生活在相同的视觉环境中，Spalax和Spalomys显示出不同程度的退化和视觉系统的专业化。Spalax的眼睛严重退化，短波视蛋白锥缺失。Spalax是盲人，但视网膜保留了其光周期感知的作用。黑腹鼠的眼睛很小，但形态正常，视网膜上富含“蓝色”视锥细胞。它保留了基本的视觉能力;然而，光作为时代钟的作用并不确定。
The hearing and visual ecology of mole-rats, Spalax ehrenbergi (Spalacidae) from Israel and Fukomys (formerly Cryptomys) anselli (Bathyergidae) from Zambia, two rodent taxa that have independently adapted to subterranean life, are reviewed and compared with epigeic counterparts, the laboratory rat and the guinea pig. In burrows, airborne sounds of low frequencies (200-800 Hz) are least attenuated and even accentuated over short distances. In both mole-rat species the frequency range of the best hearing is shifted to match the frequencies best propagated in tunnels: hearing sensitivity in the lower frequency range (< 16 kHz) has been conserved or further improved. Compared to the rat, the hearing range (covering about eight octaves) in mole-rats is not restricted but only shifted towards lower frequencies.Morphologies of the middle and inner ears of mole-rats and the guinea pig are similar in some aspects and suggest tuning to low frequencies. The middle car morphology of mole-rats does not seem to explain the lower high-frequency limit of hearing. Middle ear is not reduced or degenerated. On the contrary, the incus and the stapedial footplate are markedly enlarged, resulting in reduced sensitivity. These features can be considered an adaptation to compensate for local sound amplification in burrows. The cochlea and its components are highly specialised for sensitive perception and high resolution of low frequencies.Despite living in the same optic environment, Spalax and Fukomys show different degrees of regression and specialisation of the visual system. The eye in Spalax is severely regressed and shortwave-opsin cones are missing. Spalax is blind but the retina has retained its role for photoperiodic perception. Fukomys has small, yet morphologically normal, eyes, with a retina rich in 'blue' cones. It has retained basic visual capabilities; however, the role of light as a zeitgeber is not conclusive.