The role and application of thyroid hormones in fish physiology and aquaculture

Prosperous of fish aquaculture relied on the mass production of high quality of larvae and juveniles, which is dependent on successful initial feeding, normal development, and growth of larvae. Also, the growth and survival of newly hatched larvae are primarily attained by the impressive digestion, absorption, and utilization of nutrients following the feeding. However, numerous fish species developed for aquaculture show high mortality during early development. For mass fish production, therefore, it is important to decrease mortality. Thyroid hormones have been well known to have an important role in early development of fish and also known to be present in the eggs and newly hatched larvae and can affect fish survival and growth. There are various methods for using thyroid hormones, which consist of injection, implantation, oral administration and immersion. Regarding that, the role of thyroid hormones in development, swim bladder inflation and immunity enhances it can be used widely in aquaculture industry. In this study, the role and applications of thyroid hormones in fish physiology will be discussed, as an important strategy for improvement and development of aquaculture and it was found that the use of thyroid hormones in optimal doses could improve growth and reproductive performance in aquaculture.