自由生活於實驗魚箱中之台灣產台灣黑色鯉魚50尾,被用以研究改進其心電圖記錄方法。將導電極垂直插入右胸鰭前下方,而將游移導電極插於魚體背面左側鰓裂上緣時,所得之心電圖最為標準,且與人體心電圖第II肢導之圖型相似。本試驗結果顯示鯉魚之QRS最長不超過0.06秒;心跳速率平均為36.5次每分鐘,當以針刺激時心跳急速增加,平均增加一倍左右;低濃度之腎上腺素處理可引起竇性不整脈現象;在缺氧情形下心跳變慢或停止跳動。 Fifty fish, Cyprinus carpio, living free in water of aquarium were used for the experiment of a technical improvement of recording electrogram of heart. A typical pattern of electrogram which is similar to that of Lead II of human ECG was taken when the indifferential electrode was inserted vertically into the left side of belly above anterior portion of pectorial fin and the other exploring electrode was inserted into the dorsal margin of the left gill slit. It was shown from this report that the duration of QRS complex in fish electrogram is not longer than 0.06 seconds and heart rate is 36.5 beats per minute in average. The heart rhythm increase sharply even to two times more than that of original after stimulation with needle. A concentration of adrenalin in 0.048 mg per kilogram of body weight will induce sinus arrhythmias. Hypoxia have an effect to slow down heart beating.