Effects of stocking densities on growth of the Pacific white shrimp (Litopenaeus vannamei) in earthen ponds

The effects of stocking density and physicochemical water characteristics on the growth, survival, and production of the Pacific white shrimp, Litopenaeus vannamei, were assessed in six 500 +/- 72.5 m(2) earthen ponds during two culture seasons: autumn-winter (20 weeks) and spring-summer (14 weeks). Stocking densities were 50, 60, and 70 shrimp/m(2). Water turnover was approximately 15% per day. Aeration was supplied by a 3.5 hp air blower. Mean growth during the autumn-winter did not differ significantly among the stocking densities with final weights of 12.77, 12.72, and 12.40 g and yields of 3,609, 5,093, and 5,618 kg/ha at 50, 60, and 70 shrimp/m(2), respectively. In contrast, there were statistically significant differences in mean growth and final yields during the spring-summer. Final mean weights were 18.63, 13.46, and 11.86 g and yields were 7,243, 7,307, and 8,011 kg/ha at 50, 60, and 70 shrimp/m(2), respectively. Low water temperatures during the winter affected production. Better performance was recorded at higher spring-summer temperatures (>= 23 degrees C). Larger shrimp were associated with lower stocking density while higher stocking density produced slightly higher yields. For best performance, dissolved oxygen should be maintained above 4 mg/l.