There are growing concerns that several aquatic contaminants can indirectly alter biological interactions by inhibiting the adaptive phenotypic plasticity of organisms, even at nonlethal concentrations. In Scenedesmaceae, a family of green algae, many chemicals interfere with defensive colony formation against grazers (i.e., through induced or limited coloniality). Although several studies have demonstrated that the effects of coloniality can limit the feeding capacity of Daphnia spp., grazing inhibition in other zooplankton species is not well understood. In this study, we examined the influence of sodium octyl sulfate (SOS) on the growth and morphology of Desmodesmus subspicatus and on the feeding rates of three cladoceran species (Daphnia galeata, Bosmina longirostris, and Bosmina fatalis) feeding on SOS-induced colonies under factorial conditions of different food levels and grazer ages. SOS remarkably induced colony formation with no observed effect on growth in D. subspicatus. D. galeata and B. fatalis showed a remarkable reduction in feeding rates when they fed on colonial D. subspicatus, whereas no significant effect of the prey morphotype was found on the feeding rates of B. longirostris. Microscopic observations of algal morphology after being grazed showed that each species can consume colonial prey depending on food level and age. Comparisons of the inhibition ratio of feeding among the three cladocerans revealed that Daphnia was more sensitive to prey coloniality compared with Bosmina. Our findings provide specific insights into the effects of chemically interfered colony formation on population dynamics and community structures.

人们越来越担心，一些水生污染物可以通过抑制生物体的适应性表型可塑性来间接改变生物相互作用，即使在非致死浓度下也是如此。在栅藻科（绿藻科）中，许多化学物质会干扰针对食草动物的防御性群体形成（即通过诱导或有限的群体性）。尽管一些研究表明，群体性的影响会限制水蚤的摄食能力，但对其他浮游动物物种的放牧抑制作用尚不清楚。在本研究中，我们研究了辛基硫酸钠 (SOS) 对Desmodesmus subspicatus生长和形态的影响，以及对在 SOS 诱导的菌落中取食的三种枝角类物种（ Daphnia galeata、Bosmina longirostris和Bosmina fatalis ）的摄食率的影响。不同食物水平和放牧年龄的因素条件。SOS 显着诱导菌落形成，但未观察到对D. subspicatus的生长有影响。当D. galeata和B. fatalis以群体D. subspicatus为食时，它们的摄食率显着降低，而猎物形态类型对B. longirostris的摄食率没有显着影响。对放牧后藻类形态的显微镜观察表明，每个物种都可以根据食物水平和年龄来消耗群体猎物。比较三种枝角类的摄食抑制率，发现水蚤对猎物群体性的敏感性较Bosmina更为敏感。我们的研究结果为化学干扰菌落形成对种群动态和群落结构的影响提供了具体的见解。