Settlement and culture of post-larvae, spat and juveniles of the West Indian topshell, Cittarium pica (Linne, 1758)

Abstract

The settlement, survival and growth rates of C. pica post-larvae, spat and juveniles were evaluated under different culture conditions. The factorial effect of six stimuli (low temperature, γ-aminobutyric acid, potassium chloride, hydrogen peroxide, dibromo methane, and coralline algae extract), five types of biofilm substrates (artificial, artificial with coralline algae, artificial with congener mucus, benthic microalgae, and microalgae with congeners mucus) and five stimulation times (6, 12, 24, 36 and 72 h) on the larval settlement of the topshell were assessed. In addition, growth and survival rates of post-larvae fed with artificial biofilm and benthic microalgae were compared. Similarly, growth and survival rates were assessed in spat cultured in different environments (outdoor and indoor), and juveniles grown in concrete tanks with different finished of the inner walls (gray rough finish, and white smooth walls with epoxy paint). A higher larval settlement was observed in substrates with artificial biofilm exposed to cold water (20 °C) for 24 h. Treatments with the stimulus of KCl and dibromo methane had toxic effects on larvae. There were not differences in the shell length of the settled larvae between stimuli, substrata or exposition time. Post-larvae fed with artificial biofilm had survival and growth rates similar to those maintained with benthic microalgae biofilm. The spat that were cultured in outdoor conditions showed a higher growth rate than those kept indoor, but the survival was similar in both cases. Finally, juveniles grown in tanks with rough, gray concrete inner walls had higher growth and survival rates, compared to those held in tanks with smooth white finish. The improvements obtained in growth and survival of post-larvae, spat and juveniles of C. pica suggest that there is a great biological potential for its wild populations restocking and for its aquaculture in sea-based systems.