Embryonic development of common dentex (Dentex dentex) was investigated at nine different constant water temperatures (8 degreesC, 10 degreesC, 12 degreesC, 14 degreesC, 16 degreesC, 18 degreesC, 20 degreesC, 22 degreesC and 24 degreesC). The observed effects were compared using of regression analysis. Constant water temperatures between 12 degreesC and 18 degreesC were found to support successful embryonic development. A negative relationship between the rate of embryonic development and incubation temperature was observed. While embryonic development was completed within this range (12 degreesC-18 degreesC), there was no cell division at water temperatures of 8 degreesC and 24 degreesC. Total mortalities were observed at the 128 cleavage stage at a temperature of 10 degreesC, and after the beginning of gastrulation at 20 degreesC and 22 degreesC.