Settlement and growth of the mussel Modiolus capax (Conrad) (Bivalvia-Mytilidae) on artificial substrates in Bahia de los Angeles, Baja California, Mexico

Abstract

From March 1985 to February 1986, a study was carried out in order to determine the settlement pattern and growth of Modiolus capax mussels on artificial substrates of anchovy nets and rubber strings suspended in floating structures at three experimental stations in Bahía de los Angeles, Baja California. In September 1987, mussels were gathered from one of the floating structures, which had remained in the ocean since September 1986, in order to analyze the size structure and length-weight relation of the population. The information obtained between March 1985 and February 1986 indicated the possibility of a seasonal recruiting cycle. However, the analysis of the population gathered in September 1987 suggested the existence of a continuous settlement pattern which agrees with the results from similar studies. The implantation of Modiolus capax mussels on rubber strings was scarce and they were only found with relative abundance on mesh and nylon strings with more than two months of immersion in the ocean, previously covered up with filamentous epibiosis mainly formed by the hydroid Obelia dichoroma. Even though Modiolus capax meat weight over the total weight is higher than that of other mussels cultured, its scarce recruiting and slow growth make the possibility of culturing it more difficult.