Answer:
Producer: submerged aquatic plants; decomposer: bacteria; and consumer: small water fleas
Explanation:
The organisms that are able to produce organic food by using simple substances are called autotrophs or producers. In the given ecosystem, the aquatic plants are producers as they are able to produce organic nutrients (glucose) by the process of photosynthesis.
Decomposers are the organisms that derive their nutrition from dead animal and plant bodies. The bacteria present in the pond feed on dead water fleas and therefore, are the decomposers.
Consumers are the organisms that feed on plants and/or animals or their products. The small water fleas in the pond ecosystem are unable to make organic nutrients and derive the same from the aquatic plants. So, water fleas are consumers.
