Department of Anatomy and Cell Biology, College of Veterinary Medicine, Seoul National University, Seoul, South Korea.
Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, Hanoi, Vietnam.
J Vet Med Sci. 2023 Jun 1;85(6):625-630. doi: 10.1292/jvms.23-0128. Epub 2023 Apr 28.
Among bats, rhinolophoids and yangochiropterans, but not pteropodids, exhibit laryngeal echolocation. Although Rousettus has been regarded as the only pteropodid capable of echolocation using tongue clicks, recent evidence suggests that other species of pteropodids are also capable of echolocation using wing clicks. Studies on laryngeal echolocators suggest that delicate ear movements are essential for the echolocation behavior of bats and that the cervicoauricularis muscles play a critical role in such ear movements. In this study, we observed the gross anatomy of cervicoauricularis muscles in three species of pteropodids (Cynopterus sphinx, Eonycteris spelaea, and Rousettus leschenaultii) to examine whether ear muscle anatomy varies among pteropodids with different echolocation types and between pteropodids and laryngeal echolocating bats. We found that M. cervicoauricularis profundus originates from the nuchal crest in tongue-click echolocators (R. leschenaultii) and from the midline in wing-click echolocators (C. sphinx and E. spelaea). In general, tongue-click echolocation using high click rates is considered to be more sophisticated in terms of sonar performance than wing-click echolocation. M. cervicoauricularis profundus originating from the nuchal crest (CPNC) is not common in non-bat laurasiatherian mammals, but can be found in laryngeal echolocating bats. As it pulls the ear pinna caudally in the horizontal plane and increases the access to sound, CPNC found in R. leschenaultii and laryngeal echolocating bats may be a key characteristic of the sophisticated active echolocation behavior of bats.
在蝙蝠中，有蹄蝠和大蝙蝠亚目，但没有菊头蝠，表现出喉内回波定位。虽然 Rousettus 被认为是唯一一种能够使用舌击进行回声定位的菊头蝠，但最近的证据表明，其他菊头蝠物种也能够使用翼击进行回声定位。对喉内回波定位器的研究表明，精细的耳朵运动对于蝙蝠的回声定位行为至关重要，颈肌在这种耳朵运动中起着关键作用。在这项研究中，我们观察了三种菊头蝠（Cynopterus sphinx、Eonycteris spelaea 和 Rousettus leschenaultii）的颈肌大体解剖结构，以检查不同回声定位类型的菊头蝠和菊头蝠与喉内回波定位蝙蝠之间的耳肌解剖结构是否存在差异。我们发现，M. cervicoauricularis profundus 在舌击回声定位器（R. leschenaultii）中起源于项嵴，在翼击回声定位器（C. sphinx 和 E. spelaea）中起源于中线。一般来说，使用高点击率的舌击回声定位在声纳性能方面被认为比翼击回声定位更为复杂。起源于项嵴的 M. cervicoauricularis profundus（CPNC）在非蝙蝠劳亚兽类哺乳动物中并不常见，但在喉内回波定位蝙蝠中可以发现。由于它在水平平面上将耳屏向后拉，并增加了对声音的获取，因此在 Rousettus leschenaultii 和喉内回波定位蝙蝠中发现的 CPNC 可能是蝙蝠复杂主动回声定位行为的关键特征。
