Chemoreceptive foraging in a shallow-water scavenging lysianassid amphipod:: role of amino acids in the location of carrion in Scopelocheirus onagawae
Chemoreceptive foraging in a shallow-water scavenging lysianassid amphipod:: role of amino acids in the location of carrion in Scopelocheirus onagawae
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DOI：
10.3354/meps317193
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发表时间：
2006-01-01
影响因子：
2.5
通讯作者：
Omori, Michio
中科院分区：
文献类型：
--
作者：
Ide, Keiichiro;Takahashi, Kazutaka;Omori, Michio
海洋腐食溶酸片脚类动物依靠化学接受来有效地探测腐肉这一稀缺资源。本研究利用生物测定法研究了食腐类片脚动物的化学接受性觅食。在比目鱼肌肉提取部位中，海洋动物组织中富含的中性和碱性氨基酸，尤其是甘氨酸（Gly）、丙氨酸（Ala）和精氨酸（Arg），具有很强的刺激作用。还观察到协同作用，即酸性氨基酸（如天冬氨酸；Asp）对刺激效率的增强，这些氨基酸作为单个氨基酸具有最小的吸引力作用。引起运动反应的氨基酸阈值浓度为10(-7)mol l(-1)，在甲壳类动物中相对较低。当片脚类动物适应较低氨基酸浓度（8.0 x 10(-8) M）时，阈值处的运动反应变得更加敏感，这表明它们的觅食过程涉及感觉适应。S. onagawae的化学感受系统，即从动物组织中以低阈值浓度检测常见化学物质作为进食刺激，有利于从广阔的区域检测各种腐肉猎物。不常见氨基酸的高灵敏度、感官适应和协同作用将是在化学“噪音”环境中辨别食物气味的有益适应。由于S. onagawae是一种夜间的超低温觅食动物，本研究中发现的敏感的化学感受能力将适应于探测稀疏和有限的腐肉物品，这些腐肉的气味可以到达它们的游泳层，这表明该物种是一种专门的腐肉捕食者。
Marine scavenging lysianassid amphipods depend on chemoreception for detecting carrion, a scarce resource, efficiently. This study focused on the chemoreceptive foraging of the scavenging amphipod Scopelocheirus onagawae using bioassay. Among the extracted fraction from flounder muscle, neutral and basic amino acids, especially glycine (Gly), alanine (Ala), and arginine (Arg), which are abundant in the tissues of marine animals, showed highly stimulatory effects. Synergism, the enhancement of the stimulatory efficiency by acidic amino acids (e.g. aspartic acid; Asp) that have minimal attractive effects as individual amino acids, was also observed. The threshold concentration of amino acids leading to a locomotory response was 10(-7) mol l(-1), which is relatively low among crustaceans. The locomotory response at the threshold became more sensitive when amphipods were acclimatised to a lower concentration of amino acids (8.0 x 10(-8) M), suggesting that sensory adaptation is involved in their foraging. The chemoreceptive system in S. onagawae, i.e. the detection of common chemicals from animal tissue as feeding stimuli at low threshold concentrations, is advantageous in detecting a wide range of carrion prey items from a broad area. The high sensitivity, sensory adaptation and synergism by uncommon amino acids would be a beneficial adaptation for discriminating a food odour in an environment of chemical 'noise'. Since S. onagawae is a nocturnal suprabenthic forager, the sensitive chemoreceptive ability found in this study would be adaptive for detecting sparse and limited carrion items, the odour plume of which can reach their swimming layer, suggesting that this species is a specialised carrion feeder.