Effects of Water Temperature and Salinity on Blood Properties and Oxygen Consumption in Hagfish (Eptatretus burgeri)

Hagfish Eptatretus burgeri is classified as a agnathans and has many different physiological properties compared with vertebrates. In this study, we examined effects of water temperature and salinity on blood properties and oxygen consumption in hagfish. In the experiment of water temperature change, hematocrit (Ht), red blood cell (RBC) and glucose of hagfish blood revealed the lowest values at $15^{\circ}C$. Oxygen consumption of hagfish had significantly increased with rising water temperature, and the increasing rate was twice as much when the temperature was manipulated every $5^{\circ}C$. Also, oxygen consumption during the night time (a short photoperiod) was significantly higher than that of the daytime. Q10 level was 3.50 in the light period and 3.92 in the dark period. No significant change in plasma glucose level was showned in changing salinity from 30 psu to 22 psu, while it had rapidly increased at 20 psu ($13.7{\pm}4.0mg/dL$) and thereafter all hagfish were dead at 18 psu. However, osmolarity, $Na^+$, $K^+$ and $Cl^-$ levels had significantly decreased when salinity decreased. This results are expected to develop the artificial rearing techniques of natural hagfish.

먹장어(Eptatretus burgeri)의 혈액성상과 산소소비에 미치는 수온 및 염분의 영향