中文摘要：

在不同海水温度和不同精子密度条件下对四倍体（4n）与二倍体（2n）太平洋牡蛎（Crassostrea gigas Thunberg）离体精子的存活能力进行了比较。结果表明，四倍体与二倍体太平洋牡蛎精子的存活时间均随水温的升高和密度的降低而缩短，四倍体牡蛎精子的存活能力低于二倍体。四倍体牡蛎精子在海水温度10℃可存活8h，在28℃仅存活2h；二倍体牡蛎精子在10℃可存活12h，在28℃仅存活4h。四倍体牡蛎精子在较高密度（6．4×10^7个／mL）下可存活8h，较低密度（2．0×10^6个／mL）下低于1h；在与四倍体牡蛎精子相同的高、低密度下，二倍体存活时间分别超过10h和1h。

英文摘要：

The survival capacity of sperm from diploid （2n） and tetraploid （4n） Pacific Oysters, Crassostrea gigas in different temperatures and densities was compared in this study. The results showed that survival time of sperm from both 2n and 4n shortened with the increased temperatures and reduced densities. The survival capacity of sperm from 4n was lower than that from 2n. Sperm from 4n could survive 8 h at 10℃ and 2 h at 28℃, respectively, but the sperm from 2n can survive 12 h at 10℃ and 4 h at 28℃,respectively, but only 8 h and 2 h could the sperm from 4n survive at both temperatures. For the sperm from 4n, the survival time was about 8h in high density（6.4× 10^7 cells/mL） and less than lh in low density（2.0 × 10^6 cells/mL）. However the sperm from 2n could survive more than 10h in high density and more than lh in low density.