White abalone Haliotis sorenseni was studied in the mariculture laboratory of the Channel Islands Marine Resource Institute in southern California to determine the effect of environmental factors such as temperature, diet, light, and cultivation density on growth and survival. Fertilized eggs and larvae were raised at water temperatures of 9°C, 12°C, 15°C, 18°C, and 21°C in two separate trials. The rate of larvae development increased significantly with each 3°C change in temperature. Survival from fertilization to settlement stage was greatest (56%) at 12°C, followed by survival of 23% at 15°C, and 2% at 18°C. Larvae raised at the extremes of 21°C and 9°C had 100% mortality by 90 and 100 h posthatch. The biological zero temperature, the point at which growth stops, is projected to be 3.04°C for white abalone, significantly lower than that of sympatric species. Fecundity was determined as 7,271 eggs/g for wild-caught abalone and 6,128 eggs/g for hatchery-reared abalone and was not significantly different from previous estimates based on gonad bulk index. The effect of feed and temperature on the growth of juvenile abalone was studied. Juvenile abalone 28 mm in length were held for 147 days at 12°C, 15°C, and 18°C and fed diets of kelps Macrocystis pyriferia (L.) C. Agardh, 1820; Laminaria farlowii (Setchell, 1893); Chondracanthus exasperatus (Harvey & Bailey, 1996); Palmaria mollis (Setchell & N. L. Gardner, 1903), or combinations of these algae. Juveniles displayed fastest growth at 15°C when fed M. pyriferia. Juvenile survival was highest at 12°C and lowest at 18°C, at which temperature animals succumbed to withering syndrome. Optimal seawater temperatures for both larval and juvenile white abalone were determined to be significantly lower than previously reported. In other experiments, animals 20mmin length stocked at 25 gm/L grew at 41 µm/day versus 32 µm/day for those at 50 gm/L. No significant difference in growth was observed for abalone grown under low lighting conditions (3%–5% ambient) and almost complete darkness (1% ambient light).