刺参对生境的选择性及其行为生理响应

在室内模拟环境条件下, 研究了刺参(Apostichopus japonicus)对鳗草(Zostera marina)、裸沙和石块生境的选择性和偏好性, 比较分析了刺参在不同生境的平均聚集率、行为特征(爬行、摄食与排泄行为)和生理状态(刺参肌肉ATP含量、体腔液多巴胺、肾上腺素、去甲肾上腺素和皮质醇含量)。结果显示: (1)刺参对鳗草生境的选择和偏好显著高于裸沙生境与石块生境, 其在鳗草生境的平均聚集率达到64%, 是裸沙生境的4.5倍; (2)刺参在鳗草生境的行为活动显著高于石块生境与裸沙生境, 其爬行行为和摄食行为的出现频率是石块生境的2倍, 排泄行为明显, 刺参粪便的长度和厚度分别是裸沙生境的1.9倍和2.5倍; (3)刺参在鳗草生境的肌肉ATP含量是裸沙生境和石块生境的2倍。结果表明, 刺参对鳗草生境具有明显的选择性, 其在鳗草生境行为活跃, 免疫功能提高, 说明鳗草草床是刺参绿色生态牧场构建的优良生境。

PRELIMINARY STUDY ON THE SELECTIVITY,BEHAVIORAL AND PHYSIOLOGICAL RESPONSE OF THE SEA CUCUMBER APOSTICHOPUS JAPONICUS TO DIFFERENT HABITATS

Apostichopus japonicus, which belongs to Echinodermata, Holothuroidea, Apostichopus, is a valuable edible sea cucumber in Eastern Asia. Artificial cultivation of A. japonicus has developed rapidly to meet consumer demand and cope with the rapid decline of fishery resources caused by over-exploitation and environmental pollution. However, various diseases lead to high mortality of A. japonicus, impacting the sustainable and rapid development of aquaculture. The low genetic diversity and few high-quality economic varieties in traditional culture can also restrict the development of A. japonicus aquaculture. Green eco-ranching development based on the habitat of A. japonicus is thus important. Seagrass bed is one of the most important shallow-marine ecosystems. Zostera marina, which distribute widely in Northern China, is a natural habitat for A. japonicus. Z. marina can be a food source for A. japonicus due to its rich food resource such as organic debris, bacteria, prokaryotes living on seagrass leaves, rhizomes, and rhizospheres. Z. marina can improve the immunity of A. japonicus. Non-specific immune-related enzyme activities of A. japonicus with ingestion of Z. marina could be improved. However, there is few studies on habitat selectivity and physiological response of A. japonicus to Z. marina. We conducted experiments to investigate the selectivity, behavioral responses and physiological status of A. japonicus to different habitats. We studied the habitat selection of A. japonicus by calculating the mean attractive rate. We counted the crawling frequency and tentacles activity frequency, and measured the length and thickness of feces of A. japonicus to determine the activity of movement, feeding and digestion of A. japonicus in different habitats. Under indoor simulated environmental conditions, the selection of A. japonicus to Z. marina, bare sand and stone habitats was studied. The average aggregation rate, behavioral characteristics (crawling, feeding and excretion behavior) and physiological status (ATP content in muscle of A. japonicus; dopamine, adrenergic, norepinephrine and cortisol contents in coelomic fluid of A. japonicus) in different habitats were compared and analyzed. The results showed that: 1) A. japonicus preferred the Z. marina habitat significantly higher than bare sand habitat and stones habitat. The average aggregation rate of A. japonicus in the Z. marina habitat reached 64%, which was 4.5 times higher than that in bare sand habitat. 2) The activity of sea cucumbers in Z. marina habitat was significantly higher than those in stones and bare sand habitats, and the frequencies of crawling and feeding were 2 times higher than those in stones habitat. In Z. marina habitat, the feces length and thickness of A. japonicus was 1.9 and 2.5 times higher than those in bare sand habitat. 3) In Z. marina habitat, the content of ATP in muscle was 2 times higher than that in stones habitat and bare sand habitat. The results showed that A. japonicus had obvious selection to the habitat of Z. marina, which are active in the habitat of Z. marina and in good physiological status, indicating that the Z. marina bed is a high-quality habitat for the construction of green ecological pasture for A. japonicus.