AN ESTIMATION OF ANNUAL CLASSES AND RELATIVE GROWTH ON SAMPLES OF TWO POPULATIONS OF CONCHOLEPAS CONCHOLEPAS (Bruguiére, 1789)

Abstract

A total of 247 specimens colleted at Montemar Valparaíso in August-Septcmber, 1975 (100), November, 1977 (42) and at Tumbes, Talcahuano in October, 1967 (105) is studied. Size frcquencics for the shcll length and length of the opereula suggcst four annual groups or classes. Assuming that máximum and mínimum average growth monthly valúes given for populations of this specics in the localities of Caleta Leandro, Talcahuano and Punta Saliente, Coquimbo wcrc equivalen! to growth of adult and juveniles in other natural populations, 'an annual growth rhythm comparable to that cstimated in the graphic analysis of Montemar’s samples is obtained. Growth of the operculum parallcls that of the shell; however, its “rings” do not allow to precise age. Equations obtained to compare biometric relationships in C. concholepas and C. concholepas jernandezianus are díscussed in an Appcndix.