Endocrine Control of Salmonid Development and Seawater Adaption

This project seeks to reduce losses of fish due to improper timing of release from hatcheries by developing an accurate physiological assessment of salmon development and the endocrine mechanisms responsible for this development. Heretofore the general period for hatchery release has been decided according to the regular (Gregorian) calendar, and based on insufficient biological information. As a consequence, the actual date of hatchery release or transport for subsequent release was determined by river conditions (which in part corresponded to water releases from dams), transport facilities, hatchery logistics, and other special considerations having little to do with factors determining ultimate contribution to the salmon fishery. We plan to investigate the relation between the lunar cycle-based thyroxin surge and the several components of smoltification and to establish a reliable endocrinology of development and seawater adaptation by continuing our analysis of a variety of endocrine mechanisms.本项目旨在通过对鲑鱼发育状态开展精准生理评估，并解析该发育过程的内在内分泌调控机制，以降低孵化场放流时机不当所引发的鱼类损耗。迄今为止，孵化场放流的通用时段均依据常规公历（格里高利历）确定，且其决策依据的生物学信息并不充分。由此导致，孵化场放流或为后续放流而开展的运输的实际日期，往往由河流水文条件（部分对应大坝的泄水量）、运输设施、孵化场后勤调度及其他特殊因素决定，而这些因素几乎与决定鲑鱼渔业最终贡献量的核心影响因素无关。 我们计划探究基于月周期的甲状腺素（thyroxin）分泌峰值与幼鲑入海变态（smoltification）各环节之间的关联，并通过对多种内分泌调控机制的持续分析，建立一套可靠的发育与海水适应内分泌学评估体系。