不同生境下青海湖裸鲤(Gymnocypris przewalskii)两亚种鳃形态差异及其功能适应
Morphological differentiations of the gills of two Gymnocypris przewa-lskii subspecies in different habitats and their functional adaptations
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摘要: 该研究比较观察青海湖裸鲤(Gymnocypris przewalskii)两亚种(青海湖裸鲤指名亚种(Gymnocypris przewalskii przewalskii)和青海湖裸鲤甘子河亚种(Gymnocypris przewalskii ganzihonensis))鳃的形态及显微结构。结果显示, 指名亚种的第一鳃弓鳃耙数多、密集且较长, 而甘子河亚种则耙数少、稀疏且短;两者的鳃丝间距及鳃小片间距无明显差异, 指名亚种的鳃丝较长;指名亚种扁平上皮细胞形态以不规则椭圆形为主, 鳃丝表面有黏液细胞, 其上分布的氯细胞数量多于甘子河亚种, 而甘子河亚种扁平上皮细胞的形态以六边形为主, 鳃丝表皮未观察到黏液细胞。由此推测, 青海湖裸鲤两亚种鳃形态的差异与其食性和栖息环境相适应。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.