Abstract：
Subterranean organisms provide excellent opportunities to investigate morphological evolution, especially of sensory organs and structures and their processing areas in the central nervous system. We describe the gross morphology of the brain and some cephalic sensory organs (olfactory organ, eye, semicircular canals of the inner ear) and the swim bladder (a non-sensory accessory structure) of subterranean species of pencil catfishes of the genus Ituglanis Costa and Bockmann, 1993 (Siluriformes, Trichomycteridae) and compare them with an epigean species of the genus, Ituglanis goya Datovo, Aquino and Langeani, 2016. We compared qualitatively the size of the different brain regions and sense organs of the subterranean species with those of the epigean one, searching for modifications possibly associated with living in the subterranean environment. Our findings suggest that species of Ituglanis exhibit sensory characteristics that are preadaptive for the subterranean life, as only slight modifications were observed in the brains and sense organs of the subterranean species of the genus when compared with the epigean one. Because most subterranean fish species belong to lineages putatively preadapted for subterranean life, our results, discussed in the context of available information on the brain and sense organs of other subterranean species, help identify general trends for the evolution of the brain and sensory organs of subterranean fishes in general.
摘要：
地下生物为研究形态进化提供了极好的机会，尤其是中枢神经系统的感觉器官和结构及其处理区域。我们描述了大脑和一些头部感觉器官（嗅觉器官，眼睛,内耳的半规管）和地下物种的游泳膀胱（非感觉附属结构）ItuglanisCosta和Bockmann，1993年（Siluriformes，Trichomycteridae）并将其与该属的epigean种进行比较，ItuglanisgoyaDatovo,Aquino和Langeani,2016年。我们定性地比较了地下物种的不同大脑区域和感觉器官的大小，寻找可能与生活在地下环境中相关的修改。我们的发现表明，Ituglanis的物种表现出适应地下生活的感官特征，因为与epigean的相比，在该属的地下物种的大脑和感觉器官中仅观察到轻微的变化。因为大多数地下鱼类都属于假定为地下生活预先适应的谱系，我们的结果,在有关其他地下物种的大脑和感觉器官的可用信息的背景下进行讨论，帮助识别一般趋势的大脑和感觉器官的地下鱼类的一般进化。
