If you're asking a human, the answer is most likely going to be yes because it is generally considered among society to be a "wrong" behavior. However, Penguins have been known to trade sex for stones(for their nests), chimpanzees known to trade sex for food, humans have been known to trade sex for all of the above and more, all of these instances occurring naturally, and within nature. Therefore, if prostitution is immoral, nature is implied immoral.
If this is the case, then according to the definition of immoral: not conforming to accepted standards of morality, nature is not a socially acceptable behavior. No wonder people are so confused.
Do humans trade sex for stones?