Cultivation of the brown alga Hizikia fusiformis (Harvey) Okamura: controlled fertilization and early development of seedlings in raceway tanks in ambient light and temperature
- 254 Downloads
Commercial cultivation of the dioecious brown macroalga Hizikia fusiformis (Harvey) Okamura in East Asia depends on the supply of young seedlings from regenerated holdfasts or from wild population. Recent development of synchronized release of male and female gametes in tumble culture provides a possibility of mass production of young seedlings via sexual reproduction. In this paper, we demonstrate that controlled fertilization can be efficiently realized in ambient light and temperature in a specially designed raceway tank in which the sperm-containing water has been recirculated. The effective fertilization time of eggs by sperm was found to be within six hours. Fast growth and development of the young seedlings relied on the presence of water currents. Velocity tests demonstrated that young seedlings of 2–3 mm in length could withstand a water current of 190 cm s−1 without detachment. Culture experiments at 24 h postfertilization showed that elongation of both the seedlings and their rhizoids were not hampered by high irradiance up to 600 μmol photons m−2 s−1. However, growth was slightly retarded if cultured at a temperature of 16 ∘C compared to other culture temperatures of 22, 25 and 29 °C. No seedling detachment was observed after transfer of the young seedlings to raft cultivation in the sea after one and 1.5 months post-fertilization, indicating the feasibility of obtaining large quantity of seedlings in such a system.
KeywordsHizikia fusiformis seaweed cultivation fertilization egg release
Unable to display preview. Download preview PDF.
- Gaylord B, Reed DC, Raimondi PT, Washburn L, McLean SR (2002) A physically based model of macroalgal spore dispersal in the wave and current-dominated near shore. Ecol. 83: 1239–1251.Google Scholar
- Hwang EK, Park CS, Sohn CH (1994) Effects of light intensity and temperature on regeneration, differentiation and receptacle formation of Hizikia fusiformis (Harvey) Okamura. Korean J. Phycol. 9: 85–94.Google Scholar
- Hwang EK, Park CS, Sohn CH (1997) Culture conditions on the early growth of Hizikia fusiformis (Phaeophyta). J. Aquacult. 10: 190–211 (in Korean with English abstract).Google Scholar
- Hwang EK, Cho YC, Sohn CH (1999) Reuse of holdfasts in Hizikia cultivation. J. Korean Fish. Soc. 32: 112–116 (in Korean, with English abstract).Google Scholar
- Lüning K (1981) Egg release in gametophytes of Laminaria saccharina: induction by darkness and inhibition by blue light and UV. Br. Phycol. J. 16: 379–393.Google Scholar
- Pang SJ, Fei XG, Xiao T, Wang JC (2001) Mass production of the artificial seeds of Hizikia fusiformis by controlling egg release and fertilization. Mar. Sci. 25: 53–54 (in Chinese).Google Scholar
- ShiDao Seaweed Seedling Rearing Station (1988) Primary study on the artificial seedling rearing of Sargassum fusiforme (Harv.) Setch. Trans. Oceanol. Limnol. 2: 82–85. (in Chinese with English abstract).Google Scholar
- Starr R, Zeikus JA (1987) UTEX – The culture collection of algae at the University of Texas at Austin. J. Phycol. 23 (Suppl.): 1–47.Google Scholar
- Sun JZ, Fang JZ, Zhu ZF (1996) A preliminary study on the reproductive biology of Sargassum fursiforme. J. Zhejiang College Fish. 15: 243–249 (in Chinese with English abstract).Google Scholar
- Tseng C K, Wu CY, Sun YK (1957) The effect of temperature on the growth and development of Haidai (Laminaria japonica Aresch.). Acta Bot. Sinica. 6: 103–130 (in Chinese with English abstract).Google Scholar