EFFECTS OF SALINITY AND TEMPERATURE ON INCUBATION PERIOD, HATCHING RATE, AND MORPHOGENESIS OF THE SILVER SEA BREAM, SPARUS-SARBA (FORSKAL, 1775)

Effects of salinity and temperature on eggs of silver sea bream (Sparu s sarba) were studied in laboratory experiments. Naturally fertilized eggs were incubated under 60 different combinations of constant temper ature (13.0, 15.0, 18.5, 22.0 and 23.5 degrees C) and salinity (8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48 and 52 parts per thousand). Incuba tion period, hatching period, hatching rate, abnormalities and total l ength of newly hatched larvae were investigated. The relation between incubation period and temperature was expressed for salinity levels of 24, 28, 32, 36, 40 and 44 parts per thousand. Hatching occurred betwe en 12 and 52 parts per thousand and between 13.0 and 23.5 degrees C. H igher hatching rates of normal larvae were observed at 18.5 degrees C between 20 and 36 parts per thousand and at 22.0 degrees C between 28 and 32 parts per thousand. Largest larval size was observed at 22.0 de grees C and between 28 and 36 parts per thousand. Using multiple regre ssion analysis the calculated maximum yield of normal larvae was 66.7% at 19.4 degrees C and 31.4 parts per thousand.