Hanging culture of juveniles of the winged oyster Pteria sterna in two baskets of different design

Abstract

 The aim of this study was to determine the growth and survival of juveniles of the winged oyster Pteria sterna, culture in two types of baskets manufactured with local materials. These were ‘one floor baskets’ (OFB) and ‘three floor baskets’ (TFB), hung from two ‘long lines’ in two study sites, Ayangue and Palmar, Province of Santa Elena, Ecuador, over a five months experimental culture period. Environmental variables monitored included total particulate matter and its organic and phytoplanktonic fraction (chlorophyll a), temperature, and dissolved oxygen. Individuals showed an initial length, height (dorso-ventral) and thickness (inter-valvar) shell axis of 18.7 ± 0.32; 18.2 ± 0.29 and 7.4 ± 0.18 mm, respectively; and the soft tissue mass, shell mass and total mass were: 1.03 ± 0.04; 0.11 ± 0.005; 1.14 ± 0.04 g, respectively. At the end of the period, biometric and survival parameters were recorded. The individuals cultured in Ayangue using TFB showed increments in shell, soft tissues and total mass that were significantly higher than those from the OFB. Similar results, but with lower increments, were obtained by the individuals cultivated at Palmar site. The ANOVA II showed that the site, type of basket and the interaction between the two had a significant effect on the growth of the oysters. Survival exceeded 80% at both sites and for both basket types, but no significant differences were observed between site and basket type. Considering the growth and survival obtained for both types of baskets, we recommend the TFB baskets for winged oyster cultivation in these regions.