Temperature requirements for the growth and maturation of the gametophytes of Undaria pinnatifida and U. undarioides (Laminariales, Phaeophyceae)

Abstract

SUMMARY Gametophytes of two Undaria species, U. pinnatifida and U. undarioides (Laminariales, Phaeophyceae), were studied to determine their water temperature requirements in order to understand their different distributions in Mie Prefecture, Japan. The optimal temperature for growth was 20°C for gametophytes of both species, and the upper critical temperature for growth was also the same for both species at 28°C. Therefore, the optimal and critical temperatures for growth of the gametophytes are not the main factors determining distribution. The optimal temperature for maturation of U. pinnatifida was approximately 10–15°C, whereas it was closer to 20–21°C for U. undarioides, a difference between these species of at least 5°C. In autumn and early winter, the seawater temperature at the mouth of Ise Bay, where U. pinnatifida is distributed, ranges from 21.6°C (October) to 12.7°C (December), and off Hamajima, where U. undarioides is found, the range is from 22.7°C (October) to 19.1°C (December). The seawater temperatures from October to December, which is the maturation season for the gametophytes, agreed well with the optimal temperature requirements for maturation of the gametophytes of both species. Thus the difference in the maturation temperature range of the gametophytes is a major factor determining distribution of these Undaria species along the Japanese coast.

Thermal traits for reproduction and recruitment differ between Arctic and Atlantic kelp Laminaria digitata

“…Gametophytes are the most thermally tolerant life cycle stage in kelps, withstanding higher seawater temperatures than sporophytes [27,30,47,49,50], but upper survival temperature depends on exposure time. The gametophytes of L. digitata from Helgoland (North Sea) are able to survive 28˚C for 1 day, 26˚C for 2 days, but this limit already decreases to 24˚C after 7 days and to 23˚C after 4 weeks, thereafter being stable [30].…”

Undaria pinnatifida: A case study to highlight challenges in marine invasion ecology and management

“…Undaria 's native range has average monthly sea‐surface temperatures from −0.6 to 16.8°C in the coldest months, and 23–29.5°C in the warmest months (Dellatorre, Amoroso, Saravia, & Orensanz, ; James & Shears, ; Skriptsova et al., ; Watanabe, Nishihara, Tokunaga, & Terada, ). The ability to tolerate this large annual range is due to the survival of microscopic gametophyte and sporophyte stages which can persist at temperatures between −1 and 30°C (Morita, Kurashima, & Maegawa, ; Saito, ). Sporophyte growth has a slightly more restricted temperature range of 0–27°C; optimum growth rate is site‐specific, however, which tends to fall within 5–20°C, and senescence may be induced by exposure to temperatures at or above 24°C (Bollen, Pilditch, Battershill, & Bischof, ; Henkel & Hofmann, ; James & Shears, ; Morita, Kurashima, & Maegawa, ; Saito, ; Skriptsova et al., ).…”

Crossed Effects of Light and Temperature on the Growth and Maturation of Gametophytes in Costaria costata and Undaria pinnatifida

“…, (strain) , , Wi et al, 2008;Hwang et al, 2010). · (hybrid) (Pang et al, 1997;Morita et al, 2003;Wu et al, 2004;Choi et al, 2005;Druehl et al, 2005), , , , Westermeier et al, 2006;Hwang et al, 2009;Xu et al, 2009;Hwang et al, 2010). (Wu et al, 1994;Kaas, 1998;Li et al, 1999;Wu et al, 2004;Xu et al, 2009) 20 , (Xu et al, 2009 (Serisawa et al, 2002).…”

“…, ( , ) Kim et al, 2007a;Choi et al, 2008), ( ) (Saito, 1975). , , (Akiyama, 1965;Morita et al, 2003;Wu et al, 2004;Choi et al, 2005), (16 h) (24 h) (Tseng et al, 1959;Akiyama, 1965;Lüning, 1981;Choi et al, 2005).…”