Growth and survival of the tehuelche scallop Aequipecten tehuelchus in culture

Abstract

A cohort of juveniles Aequipecten tehuelchus was obtained on collectors placed in the San Matı́as Gulf in the 1997–1998 reproductive season, and was cultivated in circular lantern nets or screened plastic trays. An additional trial using the “ear hanging” method was ultimately terminated due to formation of excessive biofouling on the shells, although some growth and survival data were obtained for this method. After 12 months in lantern nets and trays, scallops reached a commercial size of ∼60 mm and no significant difference in shell height was observed between the two culture methods. The condition index was smaller in scallops from the “ear hanging” ( P<0.05), and was similar between scallops from lantern nets and trays ( P>0.05). The muscle index was greater in scallops from lantern nets than those held in trays ( P<0.05). Cumulative mortality of A. tehuelchus was low for the entire study with trays and lantern nets, experiencing 7.7% and 10.1%, respectively. Mortality of scallops was notably higher (32.5%) with the “ear hanging” method. No significant difference was observed between the two culture phases of intermediate and final growout. Although similar results were obtained in the culture of scallops in trays and lantern nets, the logistical superiority of lantern nets for handling the scallops favors this method for the culture of this species in the San Matı́as Gulf.