Here's why:
* Hermit crab sex is determined internally: There's no external, readily visible difference between male and female hermit crabs. You need to examine their reproductive organs to be sure.
* Claw color varies greatly: Claw color in hermit crabs can vary widely depending on the species, individual variation, and even the environment they live in. Purple claws are not a specific indicator of male sex.
* Many species have purple claws: Some hermit crab species naturally have purple claws regardless of sex.
To determine the sex of a hermit crab, you would need to consult an expert or use specialized identification guides.