Natural Cholla Wood 6"Cholla Wood Skeletons are the remains after a cholla plant dies. It is a soft wood which provides a food source for bio film that shrimp will feed on, similar to what leaves do. The holes in cholla wood provides hiding places for shrimp and fish when they are feeling vulnerable. The wood will eventually break down and disappear but it will take at least a year for the thinnest pieces and much much longer for the thicker ones. Approximately 0. 75" 1.