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Measuring Photophysiology of Attached Stage of Colacium sp. by a Cuvette-Type Fast Repetition Rate Fluorometer
Published on: November 12, 2021
Phenology, TPC and size-fractioning phenolics variability in temperate Sargassaceae (Phaeophyceae, Fucales) from
K Le Lann1, S Connan, V Stiger-Pouvreau
1LEBHAM EA 3877, European Institute of Marine Studies (IUEM), University of Western Brittany (UBO), European University of Brittany (UEB), Technopôle Brest-Iroise, 29280 Plouzané, France. klervi.lelann@gmail.com
Abstract:
The phenology of the introduced Sargassum muticum and two native species Bifurcaria bifurcata and Cystoseira baccata were monitored during eighteen months at two sites in Brittany. Density and length varied seasonally only in Sargassum. Larger individuals of Sargassum were observed in summer whereas in Cystoseira, they appeared almost in autumn. Peaks in maturity were delayed: in summer for Sargassum and in winter for Cystoseira and Bifurcaria. Phenolic contents increased before their respective reproductive period as a chemical defence. Moreover, size composition varied with site and season depending on species. In Sargassum, the quantity of small compounds decreased in summer together with an increase of 2000/5000 Da compounds. In Bifurcaria 2000/5000 Da compounds increased in summer (photoprotection) while in Cystoseira it increased in winter (protection for reproduction). Sargassum presented then a phenological plasticity not observed in native species. Moreover the three species possessed different chemical strategies to succeed in partitioning their vital space.
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