Aquaculture, vol.550, 2022 (SCI-Expanded)
© 2021Understanding the early life stage of fish can improve performance during the grow-out phase of the fish. In the present study, skeletal development and malformations were investigated in diploid and cold shock-induced triploid turbot during the early life stages. Diploid and triploid fish were reared in triplicate tanks starting from the hatching date. Thirty fish from each ploidy group (390 triploid and 390 diploid turbot) were randomly sampled at 5-day intervals. Fish skeletons were co-stained with Alician blue and Alizarin red. Growth metric (length), skeletal development, meristic characters, and malformations were examined from hatching to 60 days post-hatch (dph). There was no difference between ploidy groups in skeletal development. The vertebral elements (vertebral centra, neural arch, and haemal arch) mostly remained cartilaginous until 15 dph. Ossification of vertebral elements started on the arch and spine bases at 15 dph and were completely ossified at 20 dph. Ossification of the fins started at 15 dph at the tips of the pterygiophores and completed at 50 dph. The vertebral column ranged between 29 and 31 vertebrae, including 2–7 cephalic vertebrae, 5–9 pre-haemal vertebrae, 14–16 haemal vertebrae, and 3–5 caudal vertebrae. Between ploidy groups, there was a significant difference in the number of vertebrae. Moreover, a significant difference was also detected among ploidy groups in the number of fin rays except for pectoral fin rays. Among all of the factors, dorsal fin rays, anal fin rays, and their pterygiophores caused the main difference between ploidy groups. A total of twelve different types of malformations were detected. At least one type of malformation was observed on 260 diploid and 260 triploid fish. The most frequently encountered malformation was of the neural arch or spine. The frequency of malformed vertebra, haemal arch, and neural arch of diploid turbot was significantly higher than that of triploid counterparts on the caudal region. Malformations were most frequently observed on the caudal region of the vertebra, haemal arches, and neural arches where statistically significant differences were determined. According to the results of this study, cold shock-induced triploid turbot had no disadvantage in terms of development and remain a feasible alternative for the turbot aquaculture industry.