流速对光棘球海胆行为和生长的影响

海胆在海藻床生态系统结构和功能调控中发挥重要作用。深入理解流速对海胆摄食和生长的影响具有重要的生态学研究价值。研究了长时间(49 d)不同流速(2 cm/s, 10 cm/s和20 cm/s)对光棘球海胆幼胆(Mesocentrotus nudus,壳径：约20 mm)摄食行为、摄食量和生长的影响,以评估不同流速下,海胆摄食行为和生长的差异。实验结果表明,流速对光棘球海胆的存活无显著影响,但显著影响其生长。2 cm/s下海胆的壳径和体重显著大于10和20 cm/s。在实验开始后的第2周和第3周,2 cm/s下海胆的体重和壳径已显著高于20 cm/s。流速显著影响光棘球海胆的摄食量(P<0.001)和觅食行为(20 cm/s,P=0.004),但口器咬合行为未受显著影响(P=0.113)。管足附着时间在流速为10 cm/s和20 cm/s下显著长于其在2 cm/s。同样的,相较于2 cm/s(P=0.02)和10 cm/s(P=0.03),20 cm/s的流速可显著削弱光棘球海胆的翻正行为。综上,高流速(20 cm/s)通过影响海胆管足活动削弱其觅食行为(而非摄食行为),进而降低其...

Effects of flow velocity on behaviors and growth of the sea urchin Mesocentrotus nudus

Sea urchins play an important role in the regulation of the structure and function of the kelp bed ecosystem. Effects of flow velocity on feeding behavior and growth can improve our understanding on the ecology of sea urchins. We studied the survival, growth, feeding behaviors of the sea urchin Mesocentrotus nudus exposed to different flow velocities (2 cm/s, 10 cm/s, and 20 cm/s) over 49 days. The flow velocity significantly affected the growth of sea urchins (test diameter ~20 mm). Test diameter and body weight of sea urchins were significantly lower in the high flow velocity group, while the survival was not significantly affected. Significant differences in body weight and test diameter of sea urchins were observed in the 2^nd and 3^rd weeks after the beginning of the experiment. The long-term unidirectional water flow significantly affected food intake (P<0.001) and foraging behavior (20 cm/s, P=0.004) of M. nudus. However, Aristotle''s lantern reflex was not significantly affected by flow velocity (P=0.113). Flow velocity significantly affected the adhesion of M. nudus at 10 cm/s (P < 0.001) and 20 cm/s (P < 0.001), inhibiting the foraging of sea urchins. Consistently, the flow velocity of 20 cm/s significantly weakened the righting behavior of sea urchins compared to 2 cm/s (P=0.02) and 10 cm/s (P=0.03). Therefore, the sea area with a perennial flow velocity of 2-10 cm/s is suitable for stock enhancement of sea urchins. This study provides referable flow velocity information for better understanding the ecological habits and stock enhancement requirements of sea urchins.