Correlated responses at age 5 months and 1 year for a number of growth traits to selection for total weight and shell width in catarina scallop (Argopecten ventricosus)

Correlated responses of a number of shell and weight traits were estimated after selection in two lines of catarina scallop (Argopecten ventricosus), one selected for shell width and one for total weight. In the line selected for total weight, correlated responses of all traits were large at the age of the selection (1 year), and at 5 months. For the most important trait i n scallops, adductor muscle weight, correlated gains of 13% to 19% are expe cted when selecting the heaviest 10% individuals. The same correlated respo nse is expected for tissue weight. Correlated responses for shell length an d shell height were 4% to 5%, whereas that of shell width was 8% to 9%. In the line selected for shell width, no significant positive correlated respo nses at 5 months were seen for any trait, but negative correlated responses for shell height (-1.4% to -2.9%) and shell length (-0.6% to -3%) were sig nificant at 1 year. The importance of these negative responses is discussed in the context of selection for shell height and shell length in scallops, which could have a negative impact on shell width, a trait potentially ass ociated with reproductive performance. (C) 1999 Elsevier Science B.V. All r ights reserved.