caa a22 4500 465763774 CHVBK 20180323111907.0 cr unu---uuuuu 170327e19901001xx s 000 0 eng 10.1007/BF00239371 doi (NATIONALLICENCE)springer-10.1007/BF00239371 Wiencke C. Alfred-Wegener-Institut für Polar-und Meeresforschung, Am Handelshafen 12, D-2850, Bremerhaven, Federal Republic of Germany aut Seasonality of red and green macroalgae from Antarctica—a long-term culture study under fluctuating Antarctic daylengths [Elektronische Daten] [C. Wiencke] Summary: The seasonal development of the endemic Antarctic alga Palmaria decipiens (Palmariales, Rhodophyta) and of the Antarctic-cold temperate algae Iridaea cordata, Gigartina skottsbergii (Gigartinales, Rhodophyta), Enteromorpha bulbosa (Ulvales, Chlorophyta) and Acrosiphonia arcta (Acrosiphoniales, Chlorophyta) was monitored during two years in a culture study under fluctuating daylengths mimicking the conditions on King George Island (Antarctica). Temperature was kept constant at 0°C and nutrient levels were maintained at 0.6 moles m−3 nitrate and 0.025 moles m−3 phosphate. In P. decipiens, blades on germlings and on thalli from the previous season are initiated under Antarctic winter conditions and show maximum growth in October. Formation of blades on old thalli of I. cordata and G. skottsbergii started between June and August, maximum growth occurred in December. Sporangia started to form in G. skottsbergii in September and March and spore release was observed 9 months later at ≥27 μmol photons m−2s−1. E. bulbosa and A. arcta grew optimally in November and December conditions. Spore or gamete release was observed in December and January in plants kept at 46 μmol m −2 s−1 and in January to March in plants kept at lower photon fluence rates, respectively. The minimum light requirements for completion of the life cycle were 31.4 mol m−2 year−1 in A. arcta, 47.1 mol m−2 year−1 in E. bulbosa and P. decipiens and 141.3 molm−2 year−1 in I. cordata and G. skottsbergii. These values suggest lower distribution limits of either 53±23 m, 49 ±22 m and 38±17 m in clear offshore waters or of 28 ±5 m, 26±5 m and 20±4 m in small inshore fjords of the Antarctic Peninsula region. Springer-Verlag, 1990 Polar Biology Springer-Verlag 10/8(1990-10-01), 601-607 0722-4060 10:8<601 1990 10 300 https://doi.org/10.1007/BF00239371 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00239371 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Wiencke C. Alfred-Wegener-Institut für Polar-und Meeresforschung, Am Handelshafen 12, D-2850, Bremerhaven, Federal Republic of Germany aut NATIONALLICENCE 773 0- Polar Biology Springer-Verlag 10/8(1990-10-01), 601-607 0722-4060 10:8<601 1990 10 300 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer