Effect of egg incubation temperature on the occurrence of skeletal deformities in Solea senegalensis

Abstract

Temperature is a factor known to have a marked influence on metabolism and consequently on development, inducing ontogenetic plasticity in fish larvae. In this study, three different temperatures (15, 18 and 21°C) were assayed during Solea senegalensis embryonic development prior to hatching. After hatching all larvae were reared at the same temperature (21.0 ± 0.1°C) until 30 days. We observed that lowering the incubation temperature from 21 to 15°C reduced the incidence of skeletal deformities from 80 to 60%. Intermediate incubation temperature (18°C), resulted in larvae that displayed a rate of abnormalities close to that observed at 15°C (64%). A similar typology of deformities was observed in fish from all rearing temperatures, with caudal vertebra being the most affected structures and with a low incidence of cranial and appendicular deformities. The effect of temperature in developmental plasticity will lead to osteological abnormalities mainly affecting the caudal vertebrae at 18°C (30%) and particularly the preural vertebra at 15°C (55%). Our results, clearly demonstrate a significant effect of water temperature during egg incubation on the skeletal development of Senegalese sole, indicating that 18°C is the most appropriated temperature. These findings highlight the importance of tightly controlling temperature regimes during the early development of S. senegalensis, and the need for optimizing rearing protocols in order to avoid skeletal disorders or impaired growth.