Overwintering the black clam Chione fluctifraga in a tidal shrimp pond and in an estuary, using suspended and bottom systems

•Shrimp ponds are not used during winter season•Black clams were cultured in shrimp ponds during winter•Growth and survival responses were very promising•The species is a good candidate for overwintering purposes and to be cocultured with shrimp

The black clam Chione fluctifraga was cultured under overwintering conditions in a tidal pond (TP) used for shrimp aquaculture and in an estuary (E). Two different culturing systems were used; suspended trays (E-trays and TP-trays) and bottom enclosures (E-enclosures and TP-enclosures). The E-enclosure treatment was not considered further because of massive mortalities, possibly caused by the high organic matter content of the estuarine sediment. However, clams cultured in the rest of the treatments had high survival (> 85%). In general, clams from the TP-enclosures had the highest production response (length, width, weight, meat weight, and specific growth rate [SGR]), followed by those of the TP-trays and E-trays. All treatments had a decrease in their respective SGR when the temperature had a constant drop during the first four months (24 to 12.7 °C). However the SGR of the TP-enclosures and TP-trays at 12.7 °C was significantly higher than that of the E-trays even after the temperature began to increase. The clams from the TP-enclosures and TP-trays had a compensatory growth, whereas the E-tray clams did not recover their original growth rate. Our results are evidence of the high tolerance of the black clam to low temperatures, which suggests that it could be an adequate candidate for overwintering purposes and to be cocultured with shrimp. Apparently, the conditions of the pond were better for an optimum production performance of the species.