I believe that would be an open system.
Answer:
Nursery ponds are a subset of rearing ponds that house fish during the most delicate and difficult stages of growth
Explanation:
The answer is Porifera.
Porifera is phylum that includes sponges. <span>Their body is full of holes and it is easily for water to enter and exit these holes. </span>Sponges are commonly used for washing the dishes, but it is most likely that these are artificial sponges. Still, they are made modeled by real sponges. Rarely, the real sponges are used as bath or dish washing.
I don't know what you mean by your question, but if you are making an appropriate title it will be good if you title it that is unique and would want to make your reader more interested with your story. Just trying to help :)