Female Hermit Crabs Have Gonopores While Males Lack These Small Openings

To determine a hermit crab's gender, you must examine its underside for tiny openings called gonopores. These spots are located on the base of the pair of walking legs closest to the body on females. Males lack these spots. Identification requires the crab to be out of its shell for clear viewing.

Locating the Gonopores

The only reliable way to tell the gender of a hermit crab is by finding the gonopores. These are two small, circular pores used for reproduction. You can find them on the female crab's body where the legs attach to the torso. Specifically, they are located on the first pair of walking legs behind the pincers.

• Female Crabs: Look for two dark, pin-sized holes at the base of the legs.
• Male Crabs: This area will be completely smooth with no visible markings or holes.

Safe Handling During Inspection

To see these markings, the crab must emerge from its shell. Follow these steps to inspect the crab safely:

1. Pick the crab up gently by the back of its shell.
2. Hold the crab over a clear glass or plastic surface.
3. Wait for the crab to relax and extend its legs out of the shell.
4. Look through the bottom of the clear surface to view the underside of the legs.

Never pull a hermit crab out of its shell, as this can cause permanent physical damage or death. Patience is necessary for a successful inspection.

Comparing Identification Methods

External Characteristics

Unlike many other animals, there are no consistent differences in color, size, or pincer shape between male and female hermit crabs. Some people believe males are more aggressive, but behavior is usually tied to personality rather than gender. Using visual confirmation of the anatomy is the only factual method for identification.