Functional morphology of vermetid feeding‐tubes
Functional morphology of vermetid feeding‐tubes
复制标题
蠕虫饲管的功能形态
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
R. Cattaneo
中科院分区：
文献类型：
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作者：
S. Schiaparelli;R. Cattaneo
Vermetidae是一个小型的温水无根腹足类动物，能够建立直立的管道（喂食管）来利用水流。对一些地中海物种（三角角蚓、细粒角蚓和沙角蚓）进行的实验室和野外实验表明，这些结构的功能是探索管，不仅是为了获得更好的水流，而且主要是为了避开障碍物。事实上，在实验中，蚓类暴露于不同的水动力条件下并不产生它们，而是在存在障碍的情况下产生它们，例如大规模春季藻类生长期间的菌体。这种策略使它们能够竞争虚拟空间，而虚拟空间不是由虫体本身直接占据，而是扩散黏液网所必需的。这一解释可以提高壳形态对古环境事件的推断。当建造一个喂食管的时候，蚓类首先用它们的导管切掉它们准备转向的那一边的一部分壳，然后在不同的角度形成一个由短段组成的新管，直到它们到达想要的方向。这一过程由贝壳上的伤疤证实，这些伤疤是由一连串的薄片组成的。这些疤痕在软基质中生活的intortus Petaloconchus化石上的规律分布可以解释为周期性缺氧危机或沉积速率增加的反应。它们巨大的形态可塑性使蚓类接近于群体或模块动物。由于它们具有表达多种生长形式和重塑外壳的能力，它们成功地竞争了基质空间，成为边缘栖息地的关键物种。
Vermetidae are a small family of warm-water sessile gastropods capable of building upright tubes (feeding-tubes) to take advantage of the water flow. Laboratory and field experiments carried out on some Mediterranean species (Vermetus triquetrus, Vermetus granulatus and Serpulorbis arenaria) suggest that these structures function as exploratory tubes built not only to receive a better water flow, but mainly to avoid obstacles. In fact, vermetids experimentally exposed in situ to different hydrodynamic conditions do not produce them, but do so in the presence of an obstacle, such as thalli during the massive spring algal growth. This strategy allows them to compete for a virtual space, not directly occupied by the vermetid itself but necessary to spread its mucous net. This interpretation may improve the inference of paleo-environmental events from shell morphology. When building a feeding-tube, vermetids first cut off a portion of the shell on the side towards which they prepare to turn, using their radula, and then produce a new tube formed by short segments, at different angles, till they have reached the desired direction. This process is confirmed by the presence of scars on the shell, composed by a succession of lamellae. The regular distribution of these scars on fossil Petaloconchus intortus, which lived in soft substrates, may be interpreted as a response to periodical anoxic crises or an increase in the sedimentation rates. Their great morphological plasticity makes vermetids close to colonial or modular animals. Thanks to their capability of expressing more than one growth-form, and of re-moulding their shell, they successfully compete for substrate space and are key-stone species in fringe habitats.