1Miyazu Station, Japan Sea-Farming Association, Miyazu, Kyoto 626-0052, 2National Research Institute of Aquaculture, Nansei, Mie 516-0193, Japan
Fifty-seven male red tilefish from 35.6 to 43.2cm in total length (TL) were captured in Wakasa Bay during the maturation period (September to October). Relationships among the total length (TL), testicular weight (TW), and motility of testicular sperm (% motility) were examined. TL, TW, and % motility were 39.2±0.3cm, 1.52±0.09g, and 52.4±1.9%, respectively. As TL increased, TW increased and % motility decreased significantly (r=0.61 and r=-0.58, respectively). The total length of the male for collecting the largest amount of potent testicular sperm was calculated as 42.0cm from the equation of these regression lines.