Antonyms for "are adapted for" could include phrases such as "are ill-suited for," "are inappropriate for," or "are not designed for." These antonyms communicate the opposite meaning to the original phrase, indicating that whatever is being discussed is not well-suited or equipped for a particular purpose or environment. These antonyms may be useful in situations where it is necessary to communicate the limitations or drawbacks of a particular item or concept, or to make it clear that something is not suitable for a specific use case. By using these antonyms, speakers and writers can provide a more nuanced and complete understanding of the topic at hand.