What's eating my aponogeton distachyos?

Cape pondweed is a submerged aquatic and mostly pest-free. Water lily aphids are the primary threat, attacking the floating leaves and fragrant white flower spikes. Pond snails may graze leaf surfaces in still water. Fish (koi, goldfish) may nibble the soft foliage and disturb roots, causing browning and plant decline.

Greenish-brown clusters on floating leaf surfaces and flower spikes above water; honeydew and distorted blooms Direct a hose onto colonies to knock them into the water where fish will eat them; avoid all chemical treatments near pond water

Rasped, pitted or translucent patches on floating leaf surfaces; heavy snail populations can significantly reduce leaf area Remove snails by hand; introduce snail-eating pond inhabitants (e.g., certain loaches in ornamental ponds); avoid over-feeding fish to reduce snail food supply

Leaves nibbled or torn; crowns uprooted by fish foraging among roots, leading to plant decline Plant in weighted baskets covered with coarse gravel to protect the crown; consider a fish-free wildlife pond for best growth