光照强度对紫海胆浮游幼体生长及消化酶活性的影响

Effects of light intensity on growth and digestive enzyme activities of sea urchin (Anthocidaris crassispina) larvae

关键词:  紫海胆  光照强度  生长速度  消化酶活性

Key words:  Anthocidaris crassispina  Light intensity  Growth rate  Digestive enzyme activity

摘要:

本研究以紫海胆(Anthocidaris crassispina)为研究对象，通过水槽实验方法，模拟分析了自然光周期条件下光照强度对紫海胆浮游幼体生长、存活以及体内消化酶活性的影响，旨在为紫海胆苗种的规模化繁育提供必要的生物学参数。研究发现，在实验设计的光照强度梯度(0、500、1000、2000、3000 lx)内，光照强度对紫海胆浮游幼体的体长、躯干部骨针长度和口后腕骨针长度的影响趋势一致，影响程度由高到低为500 lx>0 lx>1000 lx>2000 lx>3000 lx。在500 lx条件下，紫海胆浮游幼体的体长、躯干部骨针长度和口后腕骨针长度都达到最高，且显著优于其他实验组(P<0.05)，此时脂肪酶和淀粉酶活性最强；在2000 lx条件下，紫海胆的胃蛋白酶活性最强；在3000 lx条件下，紫海胆浮游幼体发育到11 d已全部死亡。研究表明，在500 lx光照强度下，紫海胆浮游幼体可保持最佳的生长速度、消化酶活性以及存活率，500 lx为紫海胆浮游幼体生长发育的最佳光照强度。

Abstract:

In this study, the effects of light intensities on the growth rate (GR) and digestive enzyme activity of purple sea urchin (Anthocidaris crassispina) larvae were studied by simulating and analyzing the natural light cycle through the flume experiment method, aiming to provide necessary biological parameters for the large-scale breeding of juvenile sea urchins. The sea urchin larvae were exposed to different light intensities (0 lx, 500 lx, 1000 lx, 2000 lx, and 3000 lx) for 18 days (12 h light:12 h dark, 08:00~20:00) and samples were taken on days 8, 11, and 16). The GR was examined to identify the size (larval length, body-rod length, and post-oral arm length). The activities of digestive enzymes (amylase, lipase, and protease) were examined to elucidate their response to light intensities. At the end of the experiment, the GR under different light intensities decreased as follows: 500 lx > 0 lx > 1000 lx > 2000 lx > 3000 lx. The larval length, body-rod length, and post-oral arm length of sea urchin larvae in the 500 lx treatment were the highest among all light intensity treatments (P<0.05), and the activities of lipase and amylase were the strongest. The maximum activity of protease was observed in the 2000 lx treatment (P<0.05). By day 11, all sea urchin larvae died in the 3000 lx treatment. The results showed that the sea urchin larvae could maintain the best GR, digestive enzyme activity, and survival rate under 500 lx light intensity, which was the best light intensity for the growth and development of the sea urchin larvae.