Ecophysiological characteristics of Porphyra spp. (Bangiophyceae, Rhodophyta): seasonal and latitudinal variations in northern-central Chile

Abstract

The red macroalga Porphyra C. Agardh is one of the most ecologically successful genera that lives in the upper intertidal zone. Biochemical, physiological, and morphological acclimation strategies allow their growth and distribution as well as a quick recuperation between tidal regimens. Studies of Porphyra are poorly developed in Chile, and management and exploitation proposals need to be supported by biological and ecophysiological approaches. This study evaluated seasonal and latitudinal physiological performances of Porphyra spp. via maximum quantum yield (F v / F m), pigments, proteins, phenolic compounds, and antioxidant activity in order to describe how algae can acclimate to their environment and to provide insights to their management and use. Sampling was done at three costal sites in Chile between 25°S and 34°S between winters 2010 and 2011. A total of four different morphotypes were identified (one in the north, one in the center, and two in the south locations) and evaluated separately. Results showed seasonal and latitudinal patterns for all ecophysiological variables studied, with a general tendency of decrease in F v / F m, pigments, and soluble proteins during spring–summer seasons accompanied by an increase in the antioxidant capacity. Latitudinal differences were observed with a tendency of higher values for ecophysiological traits in central and southern morphotypes. Phenology patterns were different between an annual population in the north location and a perennial one for central-south populations. The taxonomic clarity should be evaluated in order to better understand if there exists intraspecific (dependent on morphology) or interspecific variation.