2011 Volume 58 Issue 2 Pages 181-187
Seasonal occurrence patterns of Mola sunfishes (Mola spp. A and B) in waters off the Sanriku region, eastern Japan were examined with particular focus on sea surface temperatures (SST) during 2002－2008. The two species differed from each other in both seasonal occurrence pattern and body size. SSTs during the occurrence of Mola sp. A (16.8－25.6°C) were higher than those during the occurrence of Mola sp. B (11.5－25.6°C). Although sex-ratio differences were not correlated with SSTs during the occurrence of Mola sp. B., body size and SST were negatively correlated for Mola sp. B. Thus, the occurrence patterns of Mola sunfishes around the Japanese coast may involve not only species-level characteristics but also intraspecific growth-stage differences, probably representing differences in water temperature preference.