Melatonin concentrations in Chinese mitten crabs (Eriocheir sinesis) are affected by artificial photoperiods

ABSTRACT

Melatonin is a ubiquitous and conservative biogenic amine implicated in a variety of bio-physiological processes. Although the daily variations of melatonin concentrations have been determined in many crustacean species, results have been conflicting. The present study was undertaken to evaluate the effect of different photoperiods on the circadian rhythms of melatonin in Eriocheir sinensis by using high performance liquid chromatography. The circadian rhythms of melatonin in the eyestalk of E. sinensis were influenced by external light stimulation. When under consistent light (24L:0D) and consistent dark (0L:24D), the melatonin rhythm in eyestalks and hemolymph was disturbed with respect to that of the control group (12L:12D). However, disturbance owing to different photoperiod treatments decreased with increasing treatment duration. Our results underscore the exquisite sensitivity of melatonin content to different photoperiods. These findings may have real-world implications in terms of the disruption of circadian rhythms induced by exposure to different photoperiods.

KEYWORDS:

• Melatonin
• circadian rhythms
• photoperiod
• Eriocheir sinensis
• eyestalk
• hemolymph

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 31502190], the earmarked fund for Modern Agro-industry Technology Research System [grant number CARS-48] and the Talent Introduction Program of Shenyang Agricultural University [grant number 880416005 and 880417024].