How do you determine a crayfish is male or female?

To determine a crayfish's sex, examine the swimmerets, which are small appendages located on the underside of the abdomen. In males, the first pair of swimmerets is typically larger and more rigid, often used for sperm transfer, while females have smaller, softer swimmerets that are used for carrying eggs. Additionally, males usually have a more pronounced and robust body shape compared to females. Lastly, males often have a wider gap between the last pair of swimmerets and the body.