Look at the palps
View the face from the front or side. Mature male palps are enlarged; females have slimmer, non-bulbous palps.
JUMPING SPIDER KEEPER SKILL
Sexing a jumping spider.
A visual guide to the clearest external adult feature: the pedipalps. It also explains why colour, size and juvenile markings alone are not a safe call.
WHAT TO CHECK
Mature males often show ‘boxing glove’ palps.
On mature male jumping spiders the palps are enlarged for mating, often dark and visibly bulbous. Adult females lack those swollen palps, but the exact colouring and body pattern are species-specific.
Check maturity first
The palps become diagnostic only once a male is mature. With tiny juveniles, record sex as unknown rather than guessing.
Use the underside as support
A clear adult female may show an epigyne on the underside. This needs a close, species-specific reference—not a general web pattern.
ADULT COMPARISON
Same species, two useful reference points.
These adult Phidippus audax photographs show why a side-by-side comparison helps. Notice the visibly enlarged palps on the mature male; do not rely on black-and-white colour alone for other species.
KEEP IT SAFE
Better records, fewer false calls.
Use diffuse light and a secure surface. Never flip, pin or handle an animal simply to get a sexing photo.
Use “likely” or “unknown” in the tracker when the evidence is incomplete. A later moult or adult feature can give a better answer.
For a breeding decision, share clear species, stage and multiple angles with an experienced keeper or breeder.
Reference photographs and guidance are credited beside every visual. Open the original source →