When discussing methods of cultivating aquatic organisms, particularly fish, different terms are used depending on the number of species involved. Let's look at the options provided and understand what each one means in the context of fish culture.

Understanding Fish Culture Methods

Aquaculture is a broad term that refers to the cultivation of aquatic organisms such as fish, molluscs, crustaceans, and aquatic plants under controlled or semi-controlled conditions.

• Monoculture: This method involves raising only a single species of fish or other aquatic organism in a pond, tank, or enclosure at a time.
• Polyculture: Also known as mixed culture, this method involves raising more than one species of fish or other aquatic organism simultaneously in the same body of water. The species are usually selected based on their compatibility and feeding habits to utilize different niches within the environment, potentially leading to higher overall production.

Identifying the Correct Fish Culture Term

The question specifically asks for the term used when "more than single species of fish is cultured at a time".

• Monoculture involves culturing a single species.
• Aquaculture is the general practice of cultivating aquatic organisms.
• Polyculture involves culturing multiple species simultaneously.

Based on these definitions, the term that describes culturing more than one species of fish at a time is polyculture.

Comparing Monoculture and Polyculture

Here is a simple comparison:

Since the question asks about culturing "more than single species", the correct term is polyculture.