吉首光唇鱼形态特征和染色体核型分析

Morphological characters and karyotypes of Acrossocheilus jishouensis

以采自湖南省吉首市峒河的吉首光唇鱼(Acrossocheilus jishouensis)为材料,对其形态学特征和染色体组型进行了研究。结果表明,在可数性状和可量比例性状上,吉首光唇鱼与光唇鱼属其它鱼类区别不大,其鉴别特征主要有:幼鱼体表两侧具6条清晰垂直条纹和一纵条纹,成鱼条纹逐渐模糊甚至消失;下唇两侧瓣间隙极小;背鳍末根不分枝鳍条柔软不加粗,后缘光滑;背鳍及臀鳍鳍条间膜具清晰的黑色条纹;肠道短而简单,仅两道弯曲。说明吉首光唇鱼为一有效物种。染色体标本制作采用PHA和秋水仙素腹腔注射、肾细胞直接制片法,研究结果表明,吉首光唇鱼的二倍体染色体数目为50,核型公式为2N=14M+16SM+12ST+8T,染色体臂数(NF)为80。

Morphological characteristics and kayotypes of Acrossocheilus jishouensis which were collected from Donghe river, Jishou City, Hunan Province were analyzed. The results showed that the countable characters and comparatives of measurable characters between A.fishouensis and other species of Acrossocheilus had little difference. It could be distinguished by the following characters： there were six vertical stripes and one longitudinal strip on body side of the larva, but these stripes became blurred gradually or even disappeared on body side of adult ; the gap between the two lobes of lower lip was very narrow; the last sample ray of dorsal fin was soft and smooth behind; there were clear black strikes on the membrane of dorsal and anal fin; the intestine which was short and simple just had two bends. These characters showed that A. fishouensis was a valid species. The chromosomes were obtained by using kidney celI-PHA culture in vivo and the flame- drying technique. The karyotype analysis showed that the A. jishouensis had a diploid chromosomes number of 50 and the karyotype formula was 2N = 14M ＋ 16SM ＋ 12ST ＋ 8T, NF = 80.