Teyke T
Institut für Zoologie (III) Biophysik, Johannes Gutenberg-Universität, Mainz, BRD.
Brain Behav Evol. 1990;35(1):23-30. doi: 10.1159/000115853.
Vital staining and scanning electron microscopy were used to study the morphology of superficial neuromasts in the blind cave fish, Astyanax hubbsi, and its sighted congener, Astyanax mexicanus. In blind Astyanax the neuromasts are 80 X 50 microns in size and possess cupulae with an oval basal shape. The length of the cupula is correlated to the location of its neuromast. Head neuromasts were found to have the longest cupulae (up to 300 microns), and caudal neuromasts have the smallest. Cupulae of all lengths have been observed to be easily bent by water movements. The neuromasts are directionally sensitive in that the bending of their cupulae perpendicular to the longer axis of the cupulae provides maximal excitation. A comparison of superficial neuromasts in the blind A. hubbsi to those in sighted A. mexicanus revealed several structural differences. The neuromasts in the blind fish are twice as large. Their cupulae, in particular, are much longer and seem to have supporting attachments at their edges. The greater length of the cupulae in blind cave fish may be of particular importance for the functioning of the lateral line organ, since longer cupulae protrude beyond the boundary layer in faster water currents and thus can increase the sensitivity of the neuromast. The specific morphology of the neuromasts in the blind cave fish appears to reflect an evolutionary adaptation which can serve to improve the functioning of the lateral line system and thereby compensate for the lack of eyes.
利用活体染色和扫描电子显微镜研究了盲眼洞穴鱼阿氏盲脂鲤（Astyanax hubbsi）及其有视觉的同属物种墨西哥丽脂鲤（Astyanax mexicanus）体表神经丘的形态。在盲眼的阿氏盲脂鲤中，神经丘大小为80×50微米，拥有基部呈椭圆形的杯状器。杯状器的长度与其神经丘的位置相关。发现头部神经丘的杯状器最长（可达300微米），而尾部神经丘的杯状器最小。已观察到各种长度的杯状器都很容易因水流运动而弯曲。神经丘具有方向敏感性，即其杯状器垂直于杯状器较长轴的弯曲会产生最大兴奋。对盲眼的阿氏盲脂鲤和有视觉的墨西哥丽脂鲤的体表神经丘进行比较，发现了几个结构差异。盲眼鱼的神经丘大两倍。特别是它们的杯状器长得多，并且在边缘似乎有支撑附着物。盲眼洞穴鱼杯状器更长可能对侧线器官的功能尤为重要，因为更长的杯状器在更快的水流中会突出到边界层之外，从而可以提高神经丘的敏感性。盲眼洞穴鱼神经丘的特定形态似乎反映了一种进化适应，有助于改善侧线系统的功能，从而弥补眼睛的缺失。
