不同光照强度下鹦鹉螺的行为观察

Behavior of Nautilus pompilius exposed to different illumination

由于鹦鹉螺(Nautilus pompilius)物种及构造的特殊性,在动物进化及科普教育多方面具有重要的研究价值。对人工养殖条件下鹦鹉螺对不同光照度的行为适应性进行研究。实验设定4个光照梯度(Ⅰ~Ⅳ),各梯度光照分别为:50 lx、200 lx、350 lx和450 lx,各梯度实验时间分别为1个月,并测定缸体25个不同位点照度,通过观察鹦鹉螺体态与行为变化,了解照度对鹦鹉螺行为的影响。结果显示:1)实验各照度下鹦鹉螺体态、吸附、游动及进食行为正常;2)各照度梯度未连续出现不吸附现象及灯光反应现象,第Ⅲ和第Ⅳ光照梯度两类现象出现频次增加,灯光反应现象有显著差异(P<0.05);3)随着照度增加,生长速度呈加快趋势;4)各照度梯度鹦鹉螺在缸体内各泳层及位点均有分布,分布最适照度范围依次为4.70~12.18 lx、15.39~58.90 lx、31.90~125.00 lx和42.35~75.00 lx。结果表明,实验各光照度对鹦鹉螺体态行为无明显影响,鹦鹉螺的最适光照上限为125 lx。

Because of the particularity of the Nautilus, it has important research value in animal evolution and science education. This experiment was conducted on the cultured Nautilus pompilius to study the behavior exposed to different illumination. Four illumination gradients were set up named stage I - IV, which were 50 lx,200 lx,350 lx and 450 lx respectively. The experiment time was 1 month for each illumination gradient. The illumination of 25 sites in the tank were determined under every gradient. Through the observation of the Nautilus, we were going to understand the relationship between the illumination and the behavior, also to grope the ecological characteristics of the Nautilus and the optimal illumination in cultured conditions. The observation indexes included the body appearances of the samples, the activity depth and the activity area in the tank, the non-adsorbable reaction, the behavior changes to light and the rate of growth in different stages. In this study, we found that the body appearances, adsorption, swimming and eating behavior of Nautilus pompilius were all normal under different illumination. There was no continuous appearance of non adsorption and light reaction in different illumination stages, but the times of the two phenomena increased in stage Ⅲ and Ⅳ. The percents of the non-adsorbable were about 2.2% and 1.6% respectively, and higher than the stage Ⅰ and Ⅱ （ average level ： 1.4% ）, there was no significant difference between different stages （ P 〈 0.05 ）. The light reaction results were significantly different between stage Ⅲ and Ⅳ （ P 〈 0.05 ）, the average percent of the light reaction in stage m and IV were 0.5% and 4.6% respectively. With the increase of illumination, the rate of growth was accelerating from 0. 154 mm d-1 to 0. 264 mm d 1. Their activity area was throughout the tank in all stages. The optimal illumination range in four illumination gradients were 4.70 -12.18 Ix, 15.39-58.90 Ix, 31.90 -125.00 lx and 42.35 -75.00 lx respectively. The results showed that the behavior of the Nautilus was normal under the four illumination gradients, and the highest optimal illumination was 125 lx in cultured conditions.