Evaluation of culture of the mussels Choromytilus chorus and Aulacomya ater (Molina) in northern coasts of Chile

The culture of Aulacomya ater and Choromytilus chorus in northern Chile was evaluated by collecting spat from both species from their natural environments and culturing them in an area isolated from natural populations. The spat collection at the site selected allowed the establishment of four cohorts of A. ater and six cohorts of Ch. chorus after 131 days. These cohorts were transported 250 km south for further growth, resulting in 290 ropes of Ch. chorus and 30 ropes of A. ater with an average of 900 specimens with a 13.5 mm mean size. After 29 months of cultivation, the yield was 623.7 ± 62.2 specimens of A. ater and 575.3 ± 49.3 specimens of Ch. chorus per rope of 3.5 m long. The growth attained during this period indicated values of L ∞  = 136 mm and k  = 0.58 for Ch. chorus and L ∞  = 107 mm and k  = 0.66 for A. ater . The Ch. chorus specimens reached greater lengths at month 15 than the A. ater specimens with the same age. For the total length–weight ratio and the soft part length–weight ratio for specimens above 60 mm in length, A. ater presented higher weights at the same lengths than Ch. chorus . We established that Ch. chorus reached its optimum soft part weight after 19 months and at a size of 82 mm, whereas this optimum was reached by A. ater after 18 months and at 68 mm. We concluded that farming both species in northern Chile was viable.