Title page for etd-0201113-154348


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URN etd-0201113-154348
Author Shi-jie Lin
Author's Email Address mnbvcx142000@yahoo.com.tw
Statistics This thesis had been viewed 5577 times. Download 1264 times.
Department Marine Biology
Year 2012
Semester 1
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Are there lunar patterns of gamete release in two sea urchins
(Toxopneustes pileolus and Tripneustes gratilla)?
Date of Defense 2013-01-11
Page Count 81
Keyword
  • Toxopneustes pileolus
  • Tripneustes gratilla
  • sea urchin
  • gamete release
  • Abstract For marine organisms with external fertilization, it is necessary for conspecific to release sperm and eggs in the same time. But so far, we cannot accurately predict the spawning time of many sea urchins. In this investigation, we monitored the spawning potential of Tripneustes gratilla and Toxopneustes pileolus (Echinodermata: Toxopneustidae) from April 2010 to August 2010 in southern Taiwan in order to find any pattern of spawning and its possible mechanisms. No significant lunar or semilunar rhythms were found. On the other hand, spawning potential of individuals were not randomly nor evenly distributed throughout the months in both species. High frequencies of spawning individuals occurred on certain days with no obvious rhythms. Within a day, the spawning frequencies are higher in the daytime than in the nighttime, and follow up experiments suggest a possible role of an endogenous oscillator in Toxopneustes pileolus. The possible effect of tide levels was not found. In addition, we tested noncyclical factors. Males spawned earlier and in higher frequencies than females, however no inductive ability was detected in either sexes. Significantly higher frequencies of individuals spawned when water temperature was raised, whereas no role of water disturbance was detected. We didn’t find any significant connections between Tripneustes gratilla and environmental factors. So far, water temperature and light/dark condition (through entraining their biological clocks) have been found to play a role in synchronizing the spawning Toxopneustes pileolus only.
    Advisory Committee
  • Shyh-min Chao - chair
  • Chen-chih Kao - co-chair
  • Keryea Soong - advisor
  • Files
  • etd-0201113-154348.pdf
  • indicate access worldwide
    Date of Submission 2013-02-01

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