While "rāhui" primarily refers to a "restriction" or "prohibition" in Māori culture, it also has a broader meaning of something "sacred" or "forbidden," which can be applied to certain marine creatures like stingrays. This is because stingrays are often seen as powerful creatures with a connection to the spiritual world.
Therefore, when referring to stingrays in a traditional Māori context, "rāhui" could be used as a respectful and culturally sensitive term.
However, if you're looking for a more straightforward translation, you could use "ihi", which refers to a "fish with a poisonous sting".
Ultimately, the best term to use will depend on the specific context and the desired level of formality.