The effect of elevated temperature on early embryonic development of tautog, Tautoga onitis, was the subject of a study in which both spawning adults and developing eggs were exposed to similar temperatures. When incubation temperature was gradually raised from 20.0 C, anatomical deformities, including stunted embryos and/or abnormal body curvatures, as well as increased mortality occurred between 24.2 and 26.3 C. Normal development was evident after the temperature returned to 20.0 C.