... symbol for a direct product In addition, define el and Genotype by density interaction in shrimp 547 Table I Means for BW (and SD) of P vannamei male and female adult shrimp when grown at low vs high ... variance for shrimp in the high density h environment, rlh is the additive genetic covariance across the low and high density environments, A is the numerator relationship matrix among all shrimp, and ... analysis of heritabilities of P vannamei shrimp BW at adult, mature age, after growing 102 replicated genotypes (families) at two grow-out density conditions, and an estimate of the genetic correlation...