LENGTH-BASED GROWTH PARAMETER ESTIMATES OF THE PERUVIAN SCALLOP (ARGOPECTEN-PURPURATUS)

Von Bertalanffy growth parameters of the Peruvian scallop (Argopecten purpuratus) from Peru were derived from (1) a growth experiment with suspended scallops near Independence Island (September 1987 - September 1988); (2) monthly length frequencies from a natural scallops bank at Tunga, Independence Bay (September 1987 - March 1988); (3) length frequencies data from scallops collected in Atenas (Paracas Bay) during the El Nino event 1982-1983. The growth parameters obtained using a Gulland and Holt plot for the suspended scallops were K = 2.25 year-1 and L(infinity) = 94.3 mm. The analysis of the length frequencies data yielded K and L(infinity) of 0.565 year-1 and 110 mm for the Tunga data and 2.9 year-1 and 112.0 mm for the Atenas data, respectively. The growth performance index phi' (phi' = log K + 21 og L(infinity)) was highest for scallops from Atenas (4.56) followed by those from Independence Island (4.30) and Tunga (3.83). Our results indicate that the suspended scallops from Independence Island (1987-1988) grew to a similar length to those on the bottom in Atenas during the 1982-1983 El Nino phenomenon, whereas the growth of the scallops on the bottom at Tunga was significantly inferior.