Temperature effects on early development and occurrence of metamorphosis-related morphological abnormalities in hatchery-reared brown sole Pseudopleuronectes herzensteini

The objectives of the present study are to elucidate the effects of rearing temperatures on early larval development and the occurrence of metamorphosis-related morphological abnormalities in hatchery-reared brown sole Pseudopleuronectes herzensteini. Newly hatched larvae were reared through metamorphosis at different temperatures (6, 9, 12, 15, 18, 21, and 24 °C). Growth and development of larvae were accelerated concomitant with higher temperatures. Metamorphosed juveniles were classified into four morphological categories as normal, pseudoalbinism (two types), and ambicoloration, in combination with body color (pigmentation) and eye location. Incidence of normal morphology was lowest (11–24%) and that of pseudoalbinism was highest (74–83%) at 12 °C. The highest incidence of normal morphology (51–73%) was obtained at 21 °C. Although occurrence of ambicoloration was very low in all temperature regimes (0–10%), it increased slightly with increasing temperatures. Results of the present study strongly suggested that rearing temperature during the larval period affected the appearance of normal fish because of the different larval growth and development.