Some Effects of Oxygen in Relation to Temperature on the Development of Lake Trout Embryos

Lake trout embryos were exposed to dissolved oxygen levels approximating 2.5, 3.5, 4.5, and 10.5 p.p.m. at each of four temperatures, 2.5 °C, 5.0 °C, 7.5 °C, and 10.0 °C, from fertilization to a late stage of development. The three low oxygen levels caused retardations in the developmental rates resulting in delayed hatching and lengthening of the hatching period, reduction of vitelline circulatory structures, and abnormalities of head and trunk. The low oxygen levels at 10 °C caused total mortality just prior to hatching. These results are discussed and compared with previous findings.