Age and growth of three rockfish species, Sebastes inermis, S-ventricosus and S-cheni, in the central Seto Inland Sea, Japan

Inter-specific comparison of growth was conducted among three Sebastes species (Sebastes inermis, Sebastes ventricosus and Sebastes cheni) which have previously been treated as a single species before the 2008 taxonomic review. Fish were collected in April 2010 for DNA analysis and each month from June 2011 to May 2012 for growth analysis in the central Seto Inland Sea, southwestern Japan. AFLP analysis of each of the three Sebastes species confirmed significant frequency differences in fragments. The result supported the identification of the three Sebastes species based on the morphological characters. Analysis of otoliths from a total of 94 S. inermis, 125 S. ventricosus and 71 S. cheni showed that an opaque zone at the outer margin of the sagittal otolith increased from April to October and the zone was validated as an annual ring. Growth of the three Sebastes species was estimated using the von Bertalanffy growth formula. There was no significant difference in the growth formulas between males and females within each species. The growth patterns among the three Sebastes species were significantly different and S. inermis grows slower than S. ventricosus and S. cheni in the central Seto Inland Sea.