Answer:
Energy is contained within the pond ecosystem and is transferred within the system.
The eggs of the fluke are passed into water supplies from feces and urine of infected people. After hatching the parasite actively swims and invades the body of a snail, usually by penetrating through the snail's foot. The parasite requires the presence of certain species of snails (e.g., Oncomelania, Biomphalaria, Bulinus) to transform (and multiply) itself into an infective stage, called cercaria.
A reproductive strategy presents an approach of a type of an organism to reproduction and of taking care of it's offspring.
Generaly speaking, there are two main reproductive strategies, K and R reproductive strategies.
The organisms that apply the R strategy produce a great number of small, independent offspring and when the offspring is born or hatched it's left to
try to survive on its own. This strategy is used by bacteria, many invertebrates, and reptiles.
On the other hand, the K strategy organisms produce a small number of offspring that they care of for a significant amount of time after they are born. This strategy is used mostly by mammals and birds.