黄斑蓝子鱼幼鱼对水温、盐度和溶解氧的耐受研究

Research on tolerance of juvenile Siganus oramin to water temperature,salinity and dissolved oxygen

为研究黄斑蓝子鱼(Siganus oramin)幼鱼对养殖环境的耐受力,对体质量为(3.25±0.83)g的黄斑蓝子鱼幼鱼开展了水温、盐度和溶解氧等环境因子的耐受性实验,同时监测了极限水温和盐度条件下黄斑蓝子鱼幼鱼的耗氧率和呼吸频率变化,以期为黄斑蓝子鱼的养殖生产提供参考。结果显示,黄斑蓝子鱼幼鱼适宜水温为23.0~28.0℃,可耐受的水温范围为12.1~32.5℃;适宜盐度为8.0‰~59.0‰,可耐受的盐度范围为3.5‰~75.0‰;正常环境下窒息临界点溶解氧质量浓度为(1.47±0.52)mg·L^(-1)。临近耐受极限的水温和盐度均对黄斑蓝子鱼幼鱼的窒息临界点、窒息点以及极限低氧耐受有较大影响,其中低盐对窒息点的影响最大。研究表明,黄斑蓝子鱼幼鱼对温度和盐度耐受范围较广,但超出适宜范围时耗氧率和呼吸频率均发生显著性变化,出现应激反应;黄斑蓝子鱼幼鱼窒息点高,易缺氧,建议养殖全过程溶解氧质量浓度不低于6 mg·L^(-1)。

In order to study the tolerance of juvenile Siganus oramin to cultural environmental factors and provide basic data for the cultivation,we carried out tolerance tests on juvenile S.oramin with body mass(3.25±0.83)g to environment factors such as water temperature,salinity and dissolved oxygen.Besides,we monitored their oxygen consumption rate and respiratory rate under extreme temperature and salinity conditions by hydrostatic respiration chamber methods.The results show that the suitable temperature for juvenile S.oramin ranged from 23.0 to 28.0℃,and the tolerance limit temperature ranged from 12.1 to 32.5℃;the suitable salinity ranged from 8.0‰ to 59.0‰,and the tolerance limit salinity ranged from 3.5‰to 75.0‰;the critical point of asphyxiation under normal conditions was(1.47±0.52)mg·L^(-1).Both temperature and salinity close to the tolerance limit had significant effects on critical point of asphyxiation,asphyxiation point and ultimate hypoxia tolerance of juvenile S.oramin.Low salinity had the greatest effect on critical point of asphyxiation and asphyxiation point,and low temperature had the greatest effect on ultimate hypoxic tolerance value.In conclusion,juvenile S.oramin have a wide range of tolerance to water temperature and salinity,but the oxygen consumption rate and respiration frequency change significantly when they are out of the suitable range,accompanied by strong stress response;juvenile S.oramin have a high asphyxiation point,and are prone to hypoxia,so it is recommended that the dissolved oxygen should be no less than 6 mg·L^(-1) during the aquaculture process.