多棘海盘车(Asterias amurensis)对5种双壳贝类的摄食选择性及摄食节律

摘要

研究了多棘海盘车(Asterias amurensis)对虾夷扇贝(Patinopecten yessoensis)、栉孔扇贝(Chlamys farreri)、褶牡蛎(Ostrea plicatula)、贻贝(Mytilus galloprovincialis)、菲律宾蛤仔(Ruditapes philippinarum)5种双壳贝类的摄食选择性和对栉孔扇贝的摄食节律。结果显示，在有或无日本蟳、刺参等干扰饵料的条件下，多棘海盘车对于5种双壳贝类均可摄食，且表现出明显的摄食选择性。其中，多棘海盘车对菲律宾蛤仔的摄食选择性均显著高于其他4种贝类(P<0.05)，分别为5.7、5.0、5.7、5.3、6.0只/d，干扰饵料的加入并没有对多棘海盘车的摄食选择性造成显著影响。同时，采用定时投喂饵料的方式，每隔4 h投喂一次栉孔扇贝，多棘海盘车表现出显著地昼夜摄食节律。其18：00–翌日06：00的摄食量显著高于06：00–18：00的摄食量(P<0.05)，分别为60%和40%，多棘海盘车的摄食高峰出现在18：00–22：00，摄食频率达到58%，显著高于其他时段(P<0.05)。%Asterias amurensis is one of the primary predators of bivalves that often cause massive death of cultured bivalves. Better understanding of the feeding ecophysiology of A. amurensis is the key for developing effective control strategies. In this study, we recorded the selective feeding and feeding rhythm of A. amurensis on five species of bivalves including Patinopecten yessoensis, Chlamys farreri, Ostrea plicatula, Mytilus galloprovincialis and Ruditapes philippinarum, and thus identified the characteristics of feeding of A. amurensis. The experimental animals were collected from the sea area of Zhangzi Island and then transported to our seaside laboratory at low temperature. The A. amurensis was acclimated to laboratory conditions for 10 d before the experiment. The experiment was conducted between October 22 and November 12, 2013, at the water temperature of 13−15℃, and at the salinity of 30−31, and at the dissolved oxygen level of 7.8−9.7 mg/L in a concrete tank (L×W×H=5.5 m×2.5 m×1.5m). The results showed that A. amurensis had the highest feeding rate (P<0.05) on R. philippinarum, no matter whether interfering baits, such as Charybdis japonica and Apostichopus japonicus Selenka, were present. The values were 5.7 ind/d, 5.0 ind/d, 5.7 ind/d, 5.3 ind/d and 6.0 ind/d respectively. There was no significant difference in the feeding rate when A. amurensi was fed with different interfering baits. We also observed an active feeding rhythm of A. amurensi in a diurnal cycle by feeding them with C. farreri every four hours. The percentage of food intake between 18:00 and 06:00 was apparently higher than that between 06:00 and 18:00 (60% vs 40%, P<0.05). Furthermore, we found that the feeding frequency of A. amurensis peaked between 18:00 and 22:00 (58%, P<0.05).