Mytilus: A mollusk that lives in fresh water and has two oval shells.
"Fighting between snipes and mussels" often comes from the idiom "Fighting between snipes and mussels will benefit the fisherman", which literally means fighting between snipes and mussels will benefit the fisherman in the end. The metaphor is that the two sides are deadlocked and the third party benefits from it.
Habits of mussels
Mussels generally live in the sediments of rivers, lakes, ponds and other water bodies, and the depth of diving into silt changes with the seasons. In winter, when the water temperature is low, most mussels dive into the sediment, with the front belly edge downward and the rear edge upward, and only the rear edge of the shell is exposed for breathing and feeding. Hyriopsis cumingii likes flowing water environment, and generally inhabits rivers, lakes and ponds with silt, sand and gravel at the bottom, with a pH value of 7-8. Both crested and toothless mussels can survive at PH5-9.5.