Growth and photosynthesis of the Antarctic red algae Palmaria decipiens (Palmariales) and Iridaea cordata (Gigartinales) during and following extended periods of darkness

Life strategy, ecophysiology and ecology of seaweeds in polar waters

“…In these species annual growth and reproduction is most probably based on photoperiodism and circannual rhythms, triggered or synchronized by daylength as shown for species from other phytogeographic regions (Lü ning and tom Dieck 1989; tom Dieck 1991; Lü ning and Kadel 1993; Schaffelke and Lü ning 1994). To this group belong the brown algae Desmarestia menziesii, D. antarctica, D. anceps, Himantothallus grandifolius, Phaeurus antarcticus, Ascoseira mirabilis (Wiencke 1990a;Drew and Hastings 1992;Gó mez et al 1995aGó mez et al , 1996b) and the red algae Palmaria decipiens, Delesseria salicifolia, Gymnogongrus antarcticus, G. turquetii, Hymenocladiopsis crustigena, Kallymenia antarctica, Phyllophora ahnfeltioides (Gain 1912;Wiencke 1990b;Weykam et al 1997;Dummermuth and Wiencke 2003). The second group, mainly composed of Antarctic-cold temperate species, are season responders sensu Kain (1989).…”

“…As for growth, a strong seasonal pattern of photosynthetic performance was found in longterm culture studies (Weykam and Wiencke 1996;Weykam et al 1997;Lü der et al 2001aLü der et al , 2002Lü der et al ,2003 and in field experiments (Gutkowski and Maleszewski 1989;Drew and Hastings 1992;Gó mez et al 1995b. In the brown algal season anticipators optimal photosynthetic rates are highest in late winter (September) for A. mirabilis (Gó mez et al 1995b) or in spring (November) for Himantothallus grandifolius (Drew and Hastings 1992) and D. menziesii ).…”

“…The light requirements for growth and photosynthesis of the Antarctic season anticipator Palmaria decipiens and in the Antarctic season responder Iridaea cordata are very low (Wiencke 1990b;Wiencke et al 1993;Weykam et al 1997). P. decipiens develops new blades during Antarctic late winter/spring (Wiencke 1990b) and starts growth in Antarctic winter (July) with optimum in spring (Wiencke 1990b).…”

“…The effect of darkness on the seasonal growth pattern in two Antarctic red macroalgae has been examined in long-term culture experiments by Weykam et al (1997). Growth rates in the Antarctic season anticipator P. decipiens are low or even negative during darkness but increase strongly after re-illumination with maximal growth in early spring.…”

“…This is followed later by a degradation of the chl a-containing inner antennae (Lü der et al 2002). At the end of the 6 months dark period, P. decipiens has lost its ability to photosynthesize (Lü der et al 2002;Weykam et al 1997). After re-exposure to light, pigments are synthesized rapidly and enhance photosynthetic performance to normal values within a week (Lü der et al 2002).…”