The predatory ‘clumping’ behaviour of both species is described and shown to be a form of feeding frenzy upon congenerics. Clumping behaviour also results in significantly higher rates of congeneric predation on G. d. celticus females than on G. pulex females. Support is thus given to the hypothesis that differential predation by males on moulted females may be the primary mechanism by which the introduced G. pulex has displaced the native Irish species G. d. celticus.
That sounds like adult female scuds--after molt--the other species clump onto it and eat it? I haven't seen them eat moss though, just hide under my fissidens.
Looks like I have the g. pulex? Idk.
I just trapped ~100, turkey bastered out ~100, and probably have 1000 left...
Threw about 5 tubs of these out so far, they're still visible on the substrate swimming all over the place. AGHHHH. I guess they've always been around, but after removing my platies and habrosus they are much more active.