Pedrozo H A, Wiederhold M L
Department of Otolaryngology-Head and Neck Surgery, University of Texas Health Science Center, San Antonio 78284-7777.
Hear Res. 1994 Sep;79(1-2):137-46. doi: 10.1016/0378-5955(94)90135-x.
Aplysia californica is a marine gastropod mollusc with bilaterally paired statocysts as gravity-receptor organs. Data from three experiments in which embryonic Aplysia californica were exposed to 2 x g are discussed. The experimental groups were exposed to excess gravity until hatching (9-12 day), whereas control groups were maintained at normal gravity. Body diameter was measured before exposure to 2 x g. Statocyst, statolith and body diameter were each determined for samples of 20 embryos from each group on successive days. Exposure to excess gravity led to an increase in body size. Statocyst size was not affected by exposure to 2 x g. Statolith size decreased with treatment as indicated by smaller statolith-to-body ratios observed in the 2 x g group in all three experiments. Mean statolith diameter was significantly smaller for the 2 x g group in Experiment 1 but not in Experiments 2 and 3. Defective statocysts, characterized by very small or no statoliths, were found in the 2 x g group in Experiments 1 and 2.
加州海兔是一种海洋腹足纲软体动物，具有双侧成对的平衡囊作为重力感受器官。本文讨论了三项将加州海兔胚胎暴露于2倍重力环境下的实验数据。实验组在孵化前（9 - 12天）暴露于超重环境，而对照组则维持在正常重力环境。在暴露于2倍重力之前测量了胚胎的体径。连续几天对每组20个胚胎样本分别测定平衡囊、耳石和体径。暴露于超重环境导致体型增大。平衡囊大小不受2倍重力暴露的影响。耳石大小随处理而减小，在所有三项实验中，2倍重力组的耳石与身体比例均较小。在实验1中，2倍重力组的平均耳石直径显著小于对照组，但在实验2和3中并非如此。在实验1和2的2倍重力组中发现了有缺陷的平衡囊，其特征是耳石非常小或没有耳石。
