title: [Morphological differentiations of the gills of two Gymnocypris przewa-lskii subspecies in different habitats and their functional adaptations].
abstract: Gill morphologies of two subspecies of Gymnocypris przewalskii (Gymnocypris przewalskii przewalskii and Gymnocypris przewalskii ganzihonensis) in different habitats were analyzed under scanning electron microscope. Results indicated that G. p. przewalskii had numerous long and dense-lined gill rakers while G. p. ganzihonensis had few short and scatter-lined gill rakers. There were no significant differences in distance between gill filaments (DBF) and distance gill lamella (DBL) between the two subspecies, but gill filaments of G. p. przewalskii were longer than in G. p. ganzihonensis. The electron microscopic study indicated that the pavement epithelium cells of G. p. przewalskii were well defined as irregular ovals, but were hexagonal in G. p. ganzihonensis. Moreover, G. p. przewalskii had more chloride cells than G. p. ganzihonensis, and mucous cells were only found on the surface of gill filaments of G. p. przewalskii. The morphological differences between the two subspecies of G. przewalskii are adaptations to their corresponding diets and habitats.
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810001, China. zhaokai@nwipb.ac.cn.
authors.forename: Ren-Yi
authors.initials: RY
authors.lastname: Zhang
authors.forename: Guo-Gang
authors.initials: GG
authors.lastname: Li
authors.forename: Cun-Fang
authors.initials: CF
authors.lastname: Zhang
authors.forename: Yong-Tao
authors.initials: YT
authors.lastname: Tang
authors.forename: Kai
authors.initials: K
authors.lastname: Zhao
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D003531:Cypriniformes / Q000033:anatomy & histology* / Q000145:classification / Q000502:physiology*; D017753:Ecosystem; D005880:Gills / Q000033:anatomy & histology* / Q000502:physiology / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning
keywords: Functional adaptation; Gill; Gymnocypris przewalskii; Habitat; Scanning electron microscope