The basket star Gorgonocephalus eucnemis is an aerobic organism highly dependent on dissolved oxygen in surrounding waters. Previous observations on the anatomy of Gorgonocephalus state that five pairs of ossicles (the radial shields and genital plates) regulate the position of the roof of the body disc and are responsible for flushing seawater into and out of the bursae, though this seems never to have been empirically tested. In the current study, rates of bursal ventilation were investigated in response to an increase in the availability of food and, separately, exposure to hypoxic levels of dissolved oxygen. When fed with suspended krill particles, basket stars increased rates of bursal ventilation, ranging from 13% to 155%, resulting in a similar increase in volume of water moved in and out of bursae. This rate remained elevated for an average of 25 minutes after active feeding ended. Bursal ventilation rates also increased significantly (~60% average increase) when basket stars were exposed to hypoxic conditions (dissolved oxygen ≤ 3.5 mg O2 L−1 = 2.45 mL O2 L−1). Some specimens exhibited a loss of coordination in hypoxic conditions. All specimens recovered and resumed a normal rate of bursal ventilation when returned to normoxic conditions. Measurements show that dissolved oxygen levels decreased from outside to inside bursae and suggest that dissolved oxygen is absorbed in bursae during bursal ventilations. Increasing rates of bursal ventilation may help meet the increased oxygen demands when feeding and may help animals endure some exposures to hypoxia.

中文翻译：

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Gorgonocephalus eucnemis（棘皮动物：Ophiuroidea）和法氏囊通风

篮星 Gorgonocephalus eucnemis 是一种高度依赖周围水域溶解氧的需氧生物。先前对 Gorgonocephalus 解剖结构的观察表明，五对小骨（径向盾和生殖板）调节身体椎间盘顶部的位置，并负责将海水冲入和冲出滑囊，尽管这似乎从来没有已经过经验测试。在目前的研究中，法氏囊通气率是根据食物供应的增加和单独暴露于低氧溶解氧水平来研究的。当喂食悬浮的磷虾颗粒时，篮星增加了法氏囊通风率，范围从 13% 到 155%，导致进出法氏囊的水量也有类似的增加。在主动喂食结束后，该比率平均保持升高 25 分钟。当篮子星暴露于缺氧条件（溶解氧 ≤ 3.5 mg O2 L−1 = 2.45 mL O2 L−1）时，法氏囊通气率也显着增加（平均增加约 60%）。一些标本在缺氧条件下表现出协调性丧失。当恢复到常氧条件时，所有标本都恢复并恢复了正常的法氏囊通气率。测量结果表明，溶解氧水平从滑囊的外部到内部降低，并表明在滑囊通气期间溶解氧在滑囊中被吸收。增加法氏囊通气率可能有助于满足喂养时增加的氧气需求，并可能帮助动物忍受一些缺氧暴露。当篮子星暴露于缺氧条件（溶解氧 ≤ 3.5 mg O2 L−1 = 2.45 mL O2 L−1）时，法氏囊通气率也显着增加（平均增加约 60%）。一些标本在缺氧条件下表现出协调性丧失。当恢复到常氧条件时，所有标本都恢复并恢复正常的法氏囊通气率。测量结果表明，溶解氧水平从滑囊的外部到内部降低，并表明在滑囊通气期间溶解氧在滑囊中被吸收。增加法氏囊通气率可能有助于满足喂养时增加的氧气需求，并可能帮助动物忍受一些缺氧暴露。当篮子星暴露于缺氧条件（溶解氧 ≤ 3.5 mg O2 L−1 = 2.45 mL O2 L−1）时，法氏囊通气率也显着增加（平均增加约 60%）。一些标本在缺氧条件下表现出协调性丧失。当恢复到常氧条件时，所有标本都恢复并恢复了正常的法氏囊通气率。测量结果表明，溶解氧水平从滑囊的外部到内部降低，并表明在滑囊通气期间溶解氧在滑囊中被吸收。增加法氏囊通气率可能有助于满足喂养时增加的氧气需求，并可能帮助动物忍受一些缺氧暴露。一些标本在缺氧条件下表现出协调性丧失。当恢复到常氧条件时，所有标本都恢复并恢复了正常的法氏囊通气率。测量结果表明，溶解氧水平从滑囊的外部到内部降低，并表明在滑囊通气期间溶解氧在滑囊中被吸收。增加法氏囊通气率可能有助于满足喂养时增加的氧气需求，并可能帮助动物忍受一些缺氧暴露。一些标本在缺氧条件下表现出协调性丧失。当恢复到常氧条件时，所有标本都恢复并恢复了正常的法氏囊通气率。测量结果表明，溶解氧水平从滑囊的外部到内部降低，并表明在滑囊通气期间溶解氧在滑囊中被吸收。增加法氏囊通气率可能有助于满足喂养时增加的氧气需求，并可能帮助动物忍受一些缺氧暴露。