Feast or fight: Assessing the functions of putative nematode-trapping structures in saprotrophic Agaricales.

Several species of mushroom-forming fungi have been reported to trap and consume nematodes. Nematophagy is hypothesized to have evolved as a mechanism for supplementing nitrogen, analogous to carnivorous plants. In this study, we systematically reviewed all the putative nematode-trapping saprotrophic Agaricales and documented their behavior in the presence of nematodes. Hohenbuehelia mastrucata, Pleurotus citrinopileatus, and P. djamor all trapped and consumed nematodes, as reported previously. In contrast, we found that Stropharia rugosoannulata and Coprinus comatus produce structures that have been suggested to function in nematode trapping, but these fungi neither trap nor consume the nematodes. It is possible that the structures interpreted to function in nematode trapping in S. rugosoannulata and C. comatus act as defensive mechanisms against fungivory.