Tropical mussels Perna perna and P. viridis (Bivalvia: Mytilidae): Bottom or suspended culture?

Abstract

Growth and survival of size-classes of the green Perna viridis and the brown P. perna mussels were compared in suspended and bottom culture systems in the Southern Caribbean Sea. The size-classes (juveniles, medium-size and adults) were defined in relation to somatic and reproductive characteristics of both species. Survival of P. viridis in bottom culture was close to 100% in all size groups, while in P. perna was between 75 and 80% in juveniles and medium-size and 63% in adults. Survival of P. perna in suspended culture was higher than 85% for juvenile and medium-size individuals and <60% in adults, while in P. viridis was between 60 and 70% in juveniles and medium-size and 40% in adults. Perna perna in suspended culture showed higher growth and survival rates, probably related to higher availability of phytoplanktonic biomass while on bottom culture, where seston levels were higher, P. viridis reached a higher growth rate suggesting physiological adaptations for efficient assimilation of available food resources in this environment. The results show that the culture strategy of the tropical mussel species to obtain a higher performance is different, recommending the cultivation of P. perna in suspended systems and P. viridis in bottom systems.