Abstract
To determine the temperature conditions inducing deformity of inter-nostril epidermis in the mass seedlings of red sea bream at high frequency for use as an external marker in stocking surveys for enhancement, we conducted the rearing experiments in the hatchery for mass seedlings. After the temperatures of all three intensive rearing experiments were kept at 20°C from hatching to (ca.) 5 mm (total length), their three temperatures were increased slowly from 5 mm to 8 mm. Then we kept them at 21°C, 23°C and 25°C, respectively, in mean until after 40 days after hatching. Another temperature of one rearing experiment was natural condition (23°C) in the relatively extensive experimental pond for mass seedlings. We inferred the possibility of producing a percentage of ca. 80-90% of deformed inter-nostril epidermis of mass-seedlings by controlling the temperature at 20-21°C from 0-36 days after hatching. In contrast, the percentages of deformed inter-nostril epidermis on the other higher temperatures were ca. 1-35%. Because our experiments were relative higher temperatures, it is also important to note some morphological abnormalities except deformed inter-nostril epidermis.
