Rozas Lawrence P, Odum William E
Department of Environmental Sciences, University of Virginia, Clark Hall, 22903, Charlottesville, VA, USA.
Oecologia. 1988 Oct;77(1):101-106. doi: 10.1007/BF00380932.
We conducted a series of field experiments to examine the roles of refuge and food availability in explaining the distribution and abundance of fish in tidal freshwater marsh creeks. Two hypotheses were tested: (1) relative predation pressure is less in SAV than in unvegetated areas and (2) fish food availability is greater in SAV than in nearby unvegetated areas. Tethering experiments using mummichogs (Fundulus heteroclitus) in vegetated and unvegetated areas revealed that relative predation pressure was significantly less in areas with SAV. Banded killifish (Fundulus diaphanus) maintained in vegetated enclosures consumed prey associated with SAV, whereas those held in unvegetated pens had empty stomachs. No differences were found in the number of prey eaten by bluespotted sunfish (Enneacanthus gloriosus) or mummichogs when confined in vegetated or unvegetated enclosures. However, larger prey were consumed by bluespotted sunfish and mummichogs maintained in vegetated enclosures. These data suggest that foraging profitability is significantly enhanced by feeding in the SAV. Submerged plant beds in tidal freshwater marsh creeks not only afford protection from predators, but also provide a rich foraging habitat. By foraging in SAV, fish consume larger prey and may have higher growth rates, lower mortality, and higher fecundity.
我们进行了一系列野外实验，以研究避难所和食物可利用性在解释潮汐淡水沼泽小溪中鱼类分布和丰度方面所起的作用。我们检验了两个假设：（1）与无植被区域相比，沉水植物区域的相对捕食压力较小；（2）与附近无植被区域相比，沉水植物区域的鱼类食物可利用性更高。在有植被和无植被区域使用食蚊鱼（Fundulus heteroclitus）进行的拴系实验表明，沉水植物区域的相对捕食压力显著较小。饲养在有植被围栏中的带状鳉鱼（Fundulus diaphanus）会捕食与沉水植物相关的猎物，而饲养在无植被围栏中的带状鳉鱼则空腹。当蓝点太阳鱼（Enneacanthus gloriosus）或食蚊鱼被限制在有植被或无植被的围栏中时，它们所捕食的猎物数量没有差异。然而，饲养在有植被围栏中的蓝点太阳鱼和食蚊鱼会捕食更大的猎物。这些数据表明，在沉水植物区域觅食可显著提高觅食收益。潮汐淡水沼泽小溪中的沉水植物床不仅能提供躲避捕食者的保护，还能提供丰富的觅食栖息地。通过在沉水植物区域觅食，鱼类可以捕食更大的猎物，可能具有更高的生长率、更低的死亡率和更高的繁殖力。
