盐碱胁迫对青海湖裸鲤耗氧率、血浆渗透浓度和离子浓度的影响

采用呼吸生理和血液生理的方法,探讨了性成熟青海湖裸鲤(Gymnocypris przewalskii)对盐度、碳酸盐碱度的适应性以及青海湖裸鲤在盐碱胁迫下的渗透调节和离子调节规律。将裸鲤从淡水突变到盐水(盐度14.01±0.01)、碱水(碳酸盐碱度33.03±0.01mmol·L-1)和青海湖水(盐度12.12±0.02、碳酸盐碱度29.07±0.09mmol·L-1)中,测定了在不同水质胁迫下裸鲤耗氧率、血浆渗透压和离子浓度的变化。结果表明:与淡水对照组比较,呼吸耗氧率除了盐度组在3h有显著性升高(P<0.05),其他实验组96h内均未出现显著性变化(P>0.05);裸鲤的窒息点为0.14～0.17mg·L-1,各实验组窒息点均没有显著性差异(P>0.05);碱度组血浆的渗透浓度和Na+、Cl-、Ca2+离子浓度在96h内未出现变化(P>0.05),盐度组和青海湖水组在所测时间段有显著的升高(P<0.05),并且随着胁迫时间的延长,在72h达到峰值。各实验组血浆K+浓度变化没有血浆Na+、Cl-明显,K+浓度有增高的趋势,且都在72h达到了峰值。青海湖裸鲤具有较强的盐碱耐受性,能通过渗透调节和离子调控适应高盐碱环境,而消耗能量较少。

Effects of saline-alkali stress on the oxygen consumption and plasma osmolality and ion concentrations of Gymnocypris przewalskii

By the methods of respiration physiology and blood physiology, this paper studied the adaptability of adult Gymnocypris przewalskii to salinity and carbonate alkalinity (CA) as well as the osmoregulation and ionic regulation of G. przewalskii under saline-alkali stress. The G. przewalskii individuals were directly transferred from freshwater to saline water (salinity 14.01±0.01), carbonate alkaline water (CA 33.03±0.01 mmol·L-1), and Qinghai Lake water (salinity 12.12±0.02, CA 29.07±0.09 mmol·L-1), with the oxygen consumption and plasma osmolality and ion concentrations of G. przewalskii in the waters measured. As compared with those in fresh water, the G. przewalskii individuals exposed in saline water for 3 h had a significant increase of oxygen consumption, but the individuals exposed to other test waters for 96 h had little difference in the oxygen consumption. The suffocation point of G. przewalskii was 0.14-0.17 mg·L-1, and had no significant difference among all treatments. The plasma osmolality and Na+, Cl-, and Ca2+ concentrations of the G. przewalskii exposed to carbonate alkaline water for 96 h had no significant change, but the G. przewalskii exposed to saline water and Qinghai Lake water for 96 h increased significantly, with the peak after exposed for 72 h. In all treatments, the K+ concentration in plasma varied slightly, as compared to Na+ and Cl- concentrations, and reached the highest level after 72 h exposure. It was suggested that G. przewalskii had strong tolerance to saline-alkali water, and could adapt to high saline-alkali environment through osmoregulation and ionic regulation.