Particle sorting and formation and elimination of pseudofaeces in the bivalves Mulinia edulis (siphonate) and Mytilus chilensis (asiphonate)
Particle sorting and formation and elimination of pseudofaeces in the bivalves Mulinia edulis (siphonate) and Mytilus chilensis (asiphonate)
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DOI：
10.1007/s00227-012-1879-8
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发表时间：
2012-05-01
期刊：
影响因子：
2.4
通讯作者：
Navarro, J. M.
中科院分区：
文献类型：
--
作者：
Garrido, M. V.;Chaparro, O. R.;Navarro, J. M.
紫贻贝和紫贻贝分别生活在智利雅尔达湾潮间带和潮间带不同的沉积生境中，是一种具有同形鳃的悬浮摄食型双壳贝类。它们在进料时都面临着不同的悬浮颗粒分布，都是通过产生假粪便来消除大部分无机颗粒。这项研究使用组织学、扫描和透射电子显微镜以及视频内窥镜来比较两个物种唇瓣上的颗粒处理以及颗粒分类、接受和排斥的机制。在这两个物种中，粘液结合颗粒的解聚发生在触须的褶皱表面。要被摄取的颗粒从牙冠到牙冠的前部通过触须接受道到达口腔。那些注定要被排斥的人进入皱褶之间的谷底，并向腹侧移动到触须排斥道。触点将假性粪便处理成粘液球，并将其转移到地幔排斥道。在Mulinia edulis(一种非动物群的虹吸虫)中，假粪便被储存在吸入剂虹吸器底部的一个房间里，直到通过虹吸器管壁的间歇性收缩而排出。相比之下，紫贻贝(一种附生的非虹吸虫)在淹没时会持续释放假性粪便。
Mulinia edulis and Mytilus chilensis are suspension-feeding bivalves with homorhabdic gills that live in different sedimentary habitats in the lower and upper intertidal, respectively, in Yaldad Bay, Chile. They are faced with different suspended particle size distributions when feeding, and both eliminate most of the inorganic particles by pseudofaeces production. This study used histology, scanning and transmission electron microscopy, and video endoscopy to compare particle processing on the labial palps and the mechanisms of particle sorting, acceptance, and rejection in the two species. In both species, disaggregation of mucus-bound particles occurs on the plicate surface of the palps. Particles destined for ingestion pass anteriorly from crest to crest and reach the mouth via the palp acceptance tract. Those destined for rejection enter the troughs between the plicae and move ventrally to the palp rejection tract. The palps manipulate the pseudofaeces into a mucous ball, which is transferred to the mantle rejection tract. In Mulinia edulis (an infaunal, siphonate mactrid), the pseudofaeces are stored in a chamber at the base of the inhalant siphon until expelled by intermittent contraction of the siphon wall. In contrast, Mytilus chilensis (an epifaunal, non-siphonate mytilid) releases pseudofaeces continuously when submerged.