Faculty of Biology, Institute of Environmental Sciences, Aquatic Ecosystems Group, Jagiellonian University, ul. Gronostajowa 7, 30-387, Kraków, Poland.
Microb Ecol. 2020 Jan;79(1):73-83. doi: 10.1007/s00248-019-01398-4. Epub 2019 Jun 24.
Intraguild predation (IGP) is a widespread interaction combining predation and competition. We investigated a unique IGP example among predacious fungus Zoophagus sp. and two rotifers, the predacious Cephalodella gibba and the common prey Lecane inermis. We checked the influence of the fungus on its competitor C. gibba and their joint influence on shared prey L. inermis, and the impact of the competitive predator on the growth of predacious fungus. The experiment on grown mycelium showed that Zoophagus strongly, negatively influences the growth of C. gibba (intermediate consumer) whose number did not increase throughout the experiment. The intermediate consumer was also trapped by Zoophagus and become extinct when it was its only prey, whereas in the absence of the fungus and with unlimited access to prey, its number grew quickly. As only few C. gibba were trapped by fungi when common preys were present, competition for food seems to have stronger effect on intermediate consumer population than predation. The experiment with conidia of the fungus showed that intermediate consumer significantly limits the growth of Zoophagus by reducing the number of available prey. It was observed that although the fungus can trap C. gibba, the latter does not support its growth. Trapping the intermediate consumer might serve to eliminate a competitor rather than to find a source of food. The chances of survival for L. inermis under the pressure of the two competing predators are scarce. It is the first example of IGP involving representatives of two kingdoms: Fungi and Animalia.
种内捕食（IGP）是一种广泛存在的捕食和竞争相结合的相互作用。我们研究了捕食性真菌 Zoophagus sp.与两种轮虫——捕食性 Cephalodella gibba 和常见猎物 Lecane inermis 之间独特的 IGP 实例。我们检查了真菌对其竞争者 C. gibba 的影响及其对共同猎物 L. inermis 的共同影响，以及竞争捕食者对捕食性真菌生长的影响。在生长的菌丝体实验中，Zoophagus 强烈地、消极地影响了 C. gibba（中间消费者）的生长，在整个实验过程中，中间消费者的数量并没有增加。中间消费者也被 Zoophagus 困住，当它是唯一的猎物时就灭绝了，而在没有真菌且可以无限获得猎物的情况下，它的数量迅速增长。由于当有共同猎物时，只有少数 C. gibba 被真菌困住，因此食物竞争对中间消费者种群的影响似乎比捕食作用更强。带有真菌孢子的实验表明，中间消费者通过减少可用猎物的数量，显著限制了 Zoophagus 的生长。观察到，尽管真菌可以捕获 C. gibba，但后者并不支持其生长。捕食中间消费者可能是为了消除竞争者，而不是寻找食物来源。在两个竞争捕食者的压力下，L. inermis 的生存机会很少。这是第一个涉及两个王国（真菌和动物界）代表的 IGP 实例。
