2017 Volume 65 Issue 1 Pages 41-50
It is necessary to delay the growth of juvenile puffer Takifugu rubripes for efficient selection of individuals with useful mutations from the produced juvenile groups using the TILLING method. In this study, we examined the effect of temperature on growth of juveniles. Juveniles of about 30, 50 and 70 mm in initial total length (TL) were put into 200 l tanks with a recirculating system and trials were carried out in triplicate. The fish were reared at different temperatures (17, 20, 23, 26 and 29℃) for seven days. Daily increments in TL of juveniles were largest at 26 and 29℃ for the 30 mm size (2.0-2.1 mm/day) and at 23-29℃ for the 50 and 70 mm size (1.7-2.0 and 1.3-1.4 mm/day, respectively), and smallest at 17℃ for all sizes (0.6-0.8 mm/day). Durations of optimum size (45-100 mm in TL) for selection at 17, 20 and 23-29℃ were estimated as 80.2, 49.1 and 35.4-36.3 days, respectively. This shows that the duration was 2.2- or 1.4- folds prolonged at 17 or 20℃ compared with the durations at 23-29℃. Therefore, low temperature rearing of juveniles is considered optimal for the selection system using the TILLING method.
