THE FEEDING MECHANISM OF YOLDIA (= AEQUIYOLDIA) EIGHTSI (COURTHOUY)
THE FEEDING MECHANISM OF YOLDIA (= AEQUIYOLDIA) EIGHTSI (COURTHOUY)
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DOI：
10.1098/rspb.1988.0005
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发表时间：
1988-01-22
期刊：
影响因子：
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通讯作者：
DAVENPORT, J
中科院分区：
文献类型：
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作者：
DAVENPORT, J
原枝双壳类软体动物Yoldia eightsiCourthouy既是一种存款饲养者（在泥上），也是一种悬浮饲养者（在浮游流中的硅藻上，这些硅藻被捕获在栉状体上）。该物种具有类似的解剖其他Yoldispecies，但更浅的穴居者，采用更水平的壳取向比垂直穴居Yoldia limatula和Yoldia ensifera。虽然能够通过将触须长鼻伸出部分埋藏的外壳在泥的表层上进食，但Yoldia eightsi大部分时间都在完全埋藏的情况下进食。为了做到这一点，沉积物被带到地幔腔通过打开壳阀，或通过脚的运动。沉积物通过纤毛运动移动到外套腔的后部，在那里形成一个紧凑的、被粘液包裹的沉积物段塞。蛞蝓主要通过触须长鼻子反复分类，细小的物质通过触须转移到嘴里。分选似乎是在一个简单的尺寸密度的基础上进行的，大的，密集的颗粒被拒绝。分选后，蛞蝓的无机部分通过吸入虹吸管排出（“假粪柱”）。每6-35分钟排出一次。真正的粪便（“粪便羽流”）在呼出虹吸管的呼气爆发中排出的频率要高得多。假粪便的产量大约是粪便产量的170倍（以干重为基础），这表明约迪亚8只羊摄取了0.6%的加工材料。
The protobranch bivalve molluscYoldia eightsiCourthouy is both a deposit feeder (on mud) and a suspension feeder (on diatoms in the ventilatory streams, which are trapped on the ctenidia). The species has a similar anatomy to otherYoldiaspecies, but is a more shallow burrower which adopts a more horizontal shell orientation than the vertically burrowingYoldia limatulaandYoldia ensifera. Although capable of feeding on the surface layers of mud by extending its palp proboscides outside the partly buried shell,Yoldia eightsispends most of its time feeding while totally buried. To do this, sediment is taken into the mantle cavity by opening the shell valves, or by foot movements. The sediment is moved by ciliary action to the posterior part of the mantle cavity where it forms a compact, mucus-coated sediment slug. The slug is repeatedly sorted largely by the palp proboscides, fine material being transferred to the mouth via the palps. Sorting appears to be done on a simple size–density basis, with large, dense particles being rejected. After sorting, the inorganic fraction of the slug is expelled through the inhalant siphon (‘pseudofaecal plume’). Expulsions occur every 6–35 min. True faeces (‘faecal plume’) are expelled much more frequently in the expiratory bursts of water from the exhalant siphon. Pseudofaecal output is about 170 times the faecal output (on a dry mass basis), suggesting thatYoldia eightsiingests 0.6% of processed material.