Size-dependent predation on marine fish larvae by Ctenophores, Scyphomedusae, and Planktivorous fish
Size-dependent predation on marine fish larvae by Ctenophores, Scyphomedusae, and Planktivorous fish
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栉水母、镰刀鱼和食浮游鱼类对海洋鱼类幼虫的大小依赖性捕食
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发表时间：
1992
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影响因子：
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通讯作者：
E. Houde
中科院分区：
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作者：
J. H. Cowan;E. Houde
通过在 3.2 m3 中生态系统中进行的实验，估算了栉水母 Mnemiopsis leidyi、scyphomedusa Chrysaora quinqueciratha 和食浮游鱼类 Anchoa mitchilli 对海洋鱼类幼虫的尺寸依赖性捕食率。虾虎鱼幼虫的捕食率根据以下因素进行估计：1) 幼虫猎物的长度，2) 是否存在替代的 < 1 mm 浮游动物猎物，以及 3) 栉水母和栉水母之间的捕食者-猎物相互作用。三种捕食者对幼虫的消耗率普遍随着幼虫体长的增加而下降。栉水母吃的幼虫（每个捕食者 1.0 d-1）比水母（每个捕食者 7.8 d-1）或海湾鳀鱼（每个捕食者 4.0 d-1）要少，但它吃掉所有测试尺寸级别的幼虫（3.0-9.5 mm SL）。海湾鳀鱼和水母的捕食更多取决于体型：3.0-5.0 毫米的幼虫最容易受到攻击。当有浮游动物替代猎物时，栉水母和湾鳀鱼吃掉的幼虫较少，但水母对幼虫的捕食不受替代浮游动物猎物的影响。当栉水母作为替代猎物时，水母对鱼幼虫的消耗率降低了 20-25%。开发了遭遇率模型，并根据实验结果估计了其参数。模型模拟表明，幼鱼体型和脆弱性之间的关系取决于捕食者和幼体的体型、游泳速度以及行为，并且较大或生长较快的鱼类幼体并不总是不易受到捕食。
Size-dependent predation rates on marine fish larvae by the ctenophore Mnemiopsis leidyi, scyphomedusa Chrysaora quinquecirrha, and planktivorous fish Anchoa mitchilli were estimated via experiments in 3.2 m3 me-socosms. Predation rates on larvae of the goby Gobio-soma bosci were estimated in relation to 1) length of larval prey, 2) presence or absence of alternative < 1 mm zooplankton prey, and 3) a predator-prey interaction between the scyphomedusa and ctenophore. The consumption rate of larvae by the three predators generally declined as larval length increased. The ctenophore ate fewer (1.0 d-1 per predator) larvae than did the medusa (7.8 d-1 per predator) or bay anchovy (4.0 d-1 per predator), but it consumed larvae in all size classes tested (3.0–9.5 mm SL). Predation by bay anchovy and the medusa was more size-dependent: 3.0–5.0 mm larvae were most vulnerable. Fewer larvae were eaten by the ctenophore and bay anchovy when zooplankton alternative prey was available, but predation on larvae by the medusa was not influenced by alternative zooplankton prey. Consumption rate of fish larvae by the medusa was reduced 20–25% when the ctenophore was present as its alternative prey. An encounter-rate model was developed and its parameters estimated from the experimental results. Model simulations indicated that the relationship between larval size and vulnerability is dependent on size, swimming speed, and behavior of both predators and larvae, and that bigger or faster-growing fish larvae are not always less vulnerable to predation.