| 摘要: |
| 为研究缢蛏(Sinonovacula constricta)生态行为应对高盐养殖环境的响应能力，以2个缢蛏群体(“申浙一号”群体SZSC和自然群体ZRSC)为实验对象，研究了不同盐度(20、24、28和32)对缢蛏群体潜沙行为、摄食生理的影响。对比2个群体潜沙指标和摄食率(FR)的差异，其中，潜沙行为实验设置盐度应激组(缢蛏从暂养池取出放进各盐度组开始实验)和胁迫组(缢蛏在各盐度条件下胁迫24 h后开始实验)。结果显示，SZSC的120 h半致死盐度为34.04，ZRSC的120 h半致死盐度为32.04。应激组中，SZSC的半数潜沙时间(BT50)显著大于ZRSC (P<0.05)，盐度为24时，SZSC的BT50为4.2 min，显著低于盐度为28和32时的BT50；盐度为32时，SZSC潜沙深度分布更集中，潜沙率为88.33%，显著高于ZRSC(P<0.05)。而在胁迫组，SZSC中BT50显著低于ZRSC，潜沙率显著大于ZRSC (P<0.05)。摄食生理上，除对照组外，SZSC的FR均显著大于ZRSC(P<0.05)，SZSC的FR在盐度为24时达到最大值[89.54 mL/(g·h)]，显著大于其他盐度组(P<0.05)。研究表明，2个群体的生态行为均会受到盐度的影响，盐度越高，应激反应越强烈，其中，SZSC对高盐环境具有较好的耐受性。本研究从生态行为水平评估了2个缢蛏群体对高盐环境的耐受性，揭示了高盐养殖环境下缢蛏在底泥中的垂直分布情况和摄食能力，研究结果为进一步开展缢蛏耐高盐新品系的选育提供了理论参考。 |
| 关键词: 缢蛏 潜沙行为 摄食率 高盐 |
| DOI：10.19663/j.issn2095-9869.20221228001 |
| 分类号: |
| 基金项目: |
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| Burrowing and feeding responses of different populations of Sinonovacula constricta to high-salt culture environment |
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DU Xinxin,NIU Donghong,ZHANG Shuyuan,DENG Min,WANG Jie,LI Jiale
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1.Shanghai Collaborative Innovation for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai 201306, China;2.Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China;3.Sanmen Eastern Fisheries Limited, Sanmen 317100, China
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| Abstract: |
| The razor clam (Sinonovacula constricta, Class Bivalvia) is a kind of burial filter-feeding shellfish. Salinity fluctuation is an important source of pressure for water habitats. High salinity in some coastal areas of Shandong and Jiangsu impact the survival and germplasm conservation of razor clam. To study the ecological behavior response of S. constricta to high salt culture environment, two populations of razor clams were used, including "Shenzhe No.1" population (SZSC) and a natural population (ZRSC). The semi-lethal salinity level of each population was determined. The effects of control group (20) and high salinity (24, 28, 32) on burrowing and feeding behavior of razor clams were studied. The differences in burrowing indices and feeding physiology between the two populations were compared. In the burrowing behavior experiment, two groups were set; razor clams from the temporary pond were put into each salinity group to start the experiment, while the other group of razor clams were stressed under each salinity condition for 24 h and then put into each salinity group to start the experiment. The results showed that the 120 h LC50 of SZSC was 34.04, while the 120 h LC50 of ZRSC was 32.04. The burrowing behavior of razor clams could be divided into four periods: The preparation period of shell closure, the period of axe foot movement, mud digging period, and the end period of mud diving. In the non-stressed group, the burrowing time of 50% (BT50) of SZSC was significantly higher than that of ZRSC (P<0.05). The BT50 of SZSC at 24 salinity was the minimum, which was significantly lower than that of BT50 at 28 and 32 salinity. The distribution of burrowing depth of SZSC was highly concentrated: 50% of the individuals were between 7.29 and 7.55 cm. The burrowing rate was 88.33% at 32 salinity, which was significantly higher than that of ZRSC (P<0.05). In the stressed group, the BT50 of SZSC was significantly lower than that of ZRSC, while the burrowing rate was significantly higher than that of ZRSC (P<0.05). With the increase in salinity, the burrowing rate of ZRSC decreased significantly (P<0.05). The average burrowing depth of ZRSC was 7.45 cm at 32 salinity, which was significantly higher than that of SZSC (P<0.05). By comparing the experimental results of the two populations, whether in SZSC or ZRSC, the BT50 of razor clams in the stressed group was higher than that in non-stressed group at each salinity. However, there was no significant difference in BT50 between the stressed and non-stressed groups at 20 and 28 salinity among SZSC (P>0.05). The BT50 of SZSC was closer to that of the control group at 24 and 28 salinity, and the vitality of SZSC was significantly better than that of ZRSC after 24 h of salinity stress. Under high salinity, the distribution of SZSC in mud was more concentrated than that in ZRSC, and the burrowing depth was shallower. In terms of feeding physiology, the feeding rate of SZSC was significantly higher than that of ZRSC under high salinity (P<0.05). The feeding rate of SZSC reached the maximum 89.54 mL/(g·h) at 24 salinity, which was significantly higher than that of other salinity groups (P<0.05). In summary, the ecological behaviors of both populations were affected by high salinity. The higher the salinity, the stronger the stress response, with the SZSC having a higher salinity tolerance than ZRSC. In this study, the tolerance of two populations of razor clams to high salinity was evaluated at the level of ecological behavior, and the vertical distribution and feeding ability of S. constricta in sediment in a high-salt environment was revealed. The results provide a theoretical reference for the further breeding of novel high-salt-tolerant strains of S. constricta. |
| Key words: Sinonovacula constricta Burrowing behavior Feeding rate High salinity |
