Journal of Tropical Oceanography ›› 2025, Vol. 44 ›› Issue (1): 44-52.doi: 10.11978/2024069CSTR: 32234.14.2024069

• Marine Biology • Previous Articles     Next Articles

Study on the annual growth and early development of sexual reproduction of Sargassum wightii

ZENG Zhaojun1(), SUN Liwei2, XIE Enyi1()   

  1. 1. Guangdong Ocean University, Zhanjiang 524088, China
    2. Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
  • Received:2024-03-23 Revised:2024-04-15 Online:2025-01-10 Published:2025-02-10
  • Contact: XIE Enyi
  • Supported by:
    National Key Research and Development Plan of China(2022YFD2401302); Basic and Applied Basic Research Foundation of Guangdong Province, China(2022A1515010590)

Abstract:

Sargassum wightii is a common species in the Weizhou Island of Guangxi, Xuwen of Guangdong and other sea areas, and is an economic macroalgae. Understanding the annual growth and early development of macroalgae can predict the mature time of thalli and provide scientific basis for artificial seedling and cultivation of macroalgae. This paper reports the annual growth characteristics, the effect of temperature on ovulation and the early developmental process of sexual reproduction of S. wightii in the sea area of Xuwen, Guangdong. The results show that the annual growth of S. wightii can be divided into 4 periods: fast growing period, mature period, decline period and resting period. The average length of thalli reaches its maximum [(188.32±43.77) cm] in early April, exceeding 180 cm in both April and May, and less than 5 cm in late July to early November. The male and female reproductive parts of S. wightii are in the same receptacle, and the egg cell development belongs to 8-nucleui type. The culture temperature is very important to the ovulation process. Ovulation could not be achieved at 15, 27 and 30 ℃, but could be achieved at 18~24℃. The ovulation time is shortest at 24 ℃, only 3 d. The zygotes develop into germlings with rhizoid buds at 24 ℃ for about 24h, and the seedlings develop a fourth leaflet after 30 d of culture. The results of this study provide basic information for the biology, ecology, artificial seedling and cultivation of S.wightii.

Key words: Sargassum wightii, macroalgae, annual growth, sexual reproduction, early development, ovulation

CLC Number: 

  • Q944