將五種魚種(土耳其青苔鼠Garra rufa、白玉飛狐Epalzeorhynchus kallopterus、小猴飛狐Crossocheilus reticulatus、黃金青苔鼠Gyrinocheilus aymoniervar var.及青苔鼠Gyrinocheilus aymoniervar)馴養在溫度30 ℃與不同溫泉濃度(溫度25 ℃之TDS=175、500、1000及1500 mg/L)環境下,探討其受到溫度緩慢變化之最高存活溫度與最高溫度臨界值,以及受溫度急劇變化的半致死溫度。
研究結果顯示土耳其青苔鼠具最高存活溫度,小猴飛狐次之,而以白玉飛狐具最低值。土耳其青苔鼠與小猴飛狐隨著溫泉濃度的增加,耐受性有增加的現象;而白玉飛狐、黃金青苔鼠及青苔鼠則呈現降低的趨勢。
隨著溫泉濃度的增加土耳其青苔鼠之半致死溫度呈現增加的趨勢,顯示其耐受性提高的現象;而其他四種魚種會隨著溫泉濃度的增加,使半致死溫度呈現下降的趨勢,顯示四種魚的耐受性變差。 Thermal tolerance of five ornamental fish species cultured at 30 ℃ and different concentration of hot-spring ( TDS=175, 500, 1000 and 1500 mg/L at 25 ℃) were studied. The highest survival temperature due to slow temperature elevation and LT50 value of abrupt temperature elevation for each fish species (Garra rufa, Epalzeorhynchus kallopterus, Crossocheilus reticulates, Gyrinocheilus aymoniervar var. and Gyrinocheilus aymoniervar) were determined.
The results revealed that Garra rufa exhibited the highest survival temperature, followed by C. reticulates exhibited the second highest survival temperature, while E. kallopterus exhibited the lowest survival temperature. Garra rufa and C. reticulates exhibited the higher thermal tolerance when concentration of hot-spring increased. However, the other three fish species exhibited lower thermal tolerance when concentration of hot-spring increased.
Garra rufa exhibited highest tolerance, Gyrinocheilus aymoniervar exhibited second highest tolerance, while E. kallopterus exhibited lowest tolerance against LT50 value of temperature.
The LT50 value of temperature for Garra rufa was increased as concentration of hot-spring increased indicating the increase of its thermal tolerance. However, the LT50 values of temperature for the other four fish species were decreased as concentration of hot-spring increased indicating the decrease of their thermal tolerance.