FISHERIES RESEARCH INSTITUTE,MOA,TAIWAN

The fish used for this study was Acrossocheilus formosanu which had been cultivated by this laboratory. Only healthy fish without injury were selected for the experiments, of which the results are given below: The higher the weight, the fewer the number of breaths per unit time. For the same fish, the lower the water temperature, the fewer the number of breaths; The lethal high temperature was between 35.5～36.5℃, regardless of the body weight. The lethal low temperature is between 5.5～7.0℃. The higher the body weight, the lower the lethal low temperature; For the group weighting between 55～56 g, each fish consumes the oxygen of 1.73 ppm in 2.5 h at 30℃, and 0.72 ppm at 15℃, in 25 liter of water. For the group of lower weight (10～13 g), a fish consumes about 0.5 ppm in 2.5 h at both 30℃ and 15℃ water temperature, in the same water volume. Relatively unaffected by the temperature, the heavier the body weight, the more the oxygen consumes at the high temperature (30℃). The lethal low dissolved oxygen is between 1.0～1.2 ppm at 30℃, regardless of the body weights; For those of length 2.82±0.196 cm and weight 0.21± 0.42 g, they grew to 3.01 cm, 0.253 g; 3.69 cm, 0.48 g; 4.11 cm, 0.761 g; and 4.31 cm, 0.852 g, at of 15℃, 20℃, 25℃, and 30℃, respectively. It can be said that the higher the temperature, the faster the growth rate. From our investigation, the body length and weight of the fish do not show any apparent difference, at both 30℃ and 25℃, after 50 day of cultivation. It can be concluded that the most suitable temperature or cultivating Acrossocheilus formosanus is between 25～30℃.