香港牡蛎二倍体及三倍体幼虫生物学特征比较

Comparison of biological characteristics between diploid and triploid Crassostrea hongkongensis larvae

为了评估香港牡蛎二倍体及三倍体幼虫生物学特征,于2013~2015年,在湛江和北海两地比较了二倍体及三倍体幼虫生长、存活及变态差异,计算了三倍体优势率,评估了倍性与环境效应互作对其表型性状的影响。结果表明:三倍体D形幼虫显著大于二倍体幼虫,之后,伴随着个体增长,生长优势逐渐增大,15日龄时的三倍体优势率为8.9%~9.1%。三倍体幼虫存活力与二倍体相当,未出现大量致死现象。三倍体变态规格显著大于二倍体,其优势率为5.1%~5.3%;三倍体变态时间显著低于二倍体,但其变态率与二倍体相当,不存在显著差异(p>0.05)。经过双因子分析模型的方差分析检测,发现倍性和环境效应都会对香港牡蛎幼虫生长产生显著影响(p<0.001),环境是影响幼虫存活率及变态的主要因子(p<0.05)。

Survival,growth,and metamorphosis of diploid and triploid larvae of the Hong Kong oyster Crassostrea hongkongensis were investigated.Larvae were collected from sites at Zhangjiang and Beihai from 2013 to 2015.The advantage offered and the effects of ploidy and environment on phenotype were assessed.Triploid D larvae were significantly larger than diploid larvae.This growth advantage gradually increased,reaching 8.9%–9.1%at the age of 15 days.No significant mortality was observed,and viability of diploid and triploid larvae was comparable.At metamorphosis,triploid larvae were larger than diploid larvae,with a triploid advantage of 5.1%–5.3%.Moreover,the duration of metamorphosis of triploid larvae was shorter than that of diploid larvae.No notable differences in metamorphosis as such are observed between diploid and triploid larvae.Using the P×E method,ploidy and environment are found to significantly influence larval growth(p<0.001).Environment is the primary factor that affects survival and metamorphosis of Hong Kong oyster larvae(p<0.05).