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Meagre's melatonin profiles under captivity: circadian rhythmicity and light sensitiveness
- Source :
- Fish physiology and biochemistry. 44(3)
- Publication Year :
- 2017
-
Abstract
- The present study reveals the first characterization of the plasma melatonin rhythms of the meagre (Argyrosomus regius) under aquaculture conditions. Melatonin levels were monitored during a 24 h cycle under a photoperiod of 16 L:8D and under constant darkness (DD), respectively to characterize the daily rhythm of this indoleamine and to test its endogenous origin. Besides, to identify which light intensities are perceived as night or day by this species, the degree of inhibition of nocturnal melatonin production caused by increasing intensities of light was tested (3.3, 5.3, 10.5, and 120 μW/cm2), applying 1 h light pulses at Mid-Dark. The result for melatonin daily rhythm in plasma showed a typical profile: concentration remained low during all daytime points, increasing greatly during dark points, with maximum values at 16:00 and 22:00 h, zeitgeber time. Under DD conditions, the plasma melatonin profile persisted, with a similar acrophase but with a lower amplitude between subjective day and night periods, indicating this rhythm as being endogenously driven. Moreover, meagre seemed to be very sensitive to dim levels of illumination during the night, since an intensity of just 3.3 μW/cm2 inhibited melatonin production. However, only the pulse of 5.3 μW/cm2 caused a melatonin drop till daytime concentrations. Thus, the threshold of light detection by the pineal organ was suggested as being located between 3.3 and 5.3 μW/cm2. Such results are an added value for this species biology knowledge, and in consequence to its adaptation to aquaculture conditions, allowing the improvement of culture husbandry protocols.
- Subjects :
- 0301 basic medicine
Light
Physiology
Photoperiod
Captivity
Aquaculture
Aquatic Science
Argyrosomus regius
Nocturnal
Biochemistry
Melatonin
03 medical and health sciences
Rhythm
Animal science
Zeitgeber
medicine
Animals
Circadian rhythm
photoperiodism
biology
Fishes
04 agricultural and veterinary sciences
General Medicine
biology.organism_classification
Circadian Rhythm
030104 developmental biology
040102 fisheries
0401 agriculture, forestry, and fisheries
medicine.drug
Subjects
Details
- ISSN :
- 15735168
- Volume :
- 44
- Issue :
- 3
- Database :
- OpenAIRE
- Journal :
- Fish physiology and biochemistry
- Accession number :
- edsair.doi.dedup.....74c56e51f605edc27ca5e94b682acfbb