Question

Which is a biotic factor in the environment of a fresh-water fish?

Answer 1

Biotic factors in habitat of fresh water fish could be:
A predator
A disease causing organism
Available food

Explanation:

Abiotic factors for fish is water, temperature, amount of dissolved oxygen in water, etc. Penetration of sunlight is also important in fresh water habitat.

Biotic factors are predators, disease causing organisms, organisms available as food, population density of competitors, etc.