Okamura B, Partridge J C
Biol Bull. 1999 Apr;196(2):205-215. doi: 10.2307/1542566.
We describe the effects of extreme flow on the growth and morphology of a bryozoan, Membranipora membranacea, encrusting laminarian fronds in the Rapids of Lough Hyne (=Ine), County Cork, Ireland. An ultrasonic current meter was used to characterize ambient flow regimes at the level of the algal canopy over a complete tidal cycle at three sites within the Rapids. Colonies collected from sites exposed to different flows showed a trend towards miniaturization with increased flow: the zooids were less elongate, the lophophores were smaller in diameter and had fewer tentacles, and the distances between excurrent jets were shorter. These morphological changes probably place feeding surfaces into slower flow regimes of the boundary layer. Similar growth rates of colonies at sites differing in flow provide evidence that this miniaturization is adaptive and that bryozoans are capable of adopting appropriate morphological responses to varying environmental regimes. Such plasticity should be considered when assessing feeding from different flow regimes because particular colonies may be adapted to a limited and specific range of flow conditions.
我们描述了极端水流对一种苔藓虫——膜孔苔藓虫（Membranipora membranacea）生长和形态的影响，该苔藓虫附着在爱尔兰科克郡海恩湖（=伊内湖）急流中的海带叶片上。在急流中的三个地点，使用超声波流速仪在一个完整的潮汐周期内对藻类冠层水平的周围水流状态进行了表征。从暴露于不同水流的地点采集的群体呈现出随着水流增加而趋于小型化的趋势：个虫更短，触手冠直径更小且触手数量更少，排泄水流喷射口之间的距离更短。这些形态变化可能使摄食表面处于边界层中流速较慢的区域。不同水流地点的群体具有相似的生长速率，这证明这种小型化是适应性的，并且苔藓虫能够对不同的环境状态做出适当的形态反应。在评估不同水流状态下的摄食情况时应考虑这种可塑性，因为特定的群体可能适应有限且特定范围的水流条件。
