Determining the Sex of Jumping Spiders: Here’s How to Do It

When determining the sex of jumping spiders, the developed sexual characteristics are key. Colors can provide clues, but they are not a reliable test. Here, you’ll learn what to look for and when it’s better to wait a little longer.

A sharp photo is often more helpful than moving the spider around frequently. So, whenever possible, let your jumping spider rest on a clear pane of glass and observe it without touching it. It will be calm right after molting or while inside its sealed web.

Sex Determination in Jumping Spiders: The Most Important Characteristics

Männchen: Look at the buttons

Adult males have well-developed copulatory organs at the tips of their pedipalps, the short appendages in front of the body. These appear thickened. In young males, changes may already be visible before the organs are fully developed.

However, dense hair, perspective, and a blurry image can be misleading. Therefore, don’t base your judgment solely on a probe’s apparent thickness. For a reliable identification, you need a clear view and information on its stage of development.

Female: Look at the underside

In sexually mature females, the epigyne is visible on the underside of the anterior part of the abdomen. It is one of the external sexual characteristics. Its shape and visibility vary among species. Therefore, a random dark spot in a photo is not sufficient for identification.

If a young animal lacks a distinct female characteristic, that does not necessarily mean it is a “male.” The animal may simply be too young, or the photograph may not be suitable.

Sex in Phidippus regius: What Does the Color Reveal?

In Phidippus regius, adult males are usually black and white. Females can be gray, brown, or orange, among other colors, but they also exhibit a similar pattern. This variety of colors makes the species particularly fascinating and, at the same time, makes early identification difficult.

Even the iridescent chelicerae aren’t a simple color code. Females may have green or reddish-purple chelicerae. “Green means male, pink means female” is therefore not a reliable rule. Furthermore, the color depends on how the light hits the surface.

The color photos provided show examples, not a universal distinction between the sexes. Do not apply color rules for Phidippus regius to Phidippus audax or other species.

At what stage can the sex of jumping spiders be determined?

A distinct feeding pattern like FH4 is no guarantee. Species, development, and the observable expression of traits all play a role. For small juveniles, “still undetermined” is often the most honest answer.

So make a note of molts and compare them later with new, clear photos. However, you don’t need to disturb the animal immediately after every molt. Wait until it is back to its normal level of activity. An unidentified animal is still a valid specimen for observation; you don’t need to buy another one.

Determining Gender: How to Take Helpful Photos

• Take a photo from the front so that both buttons are as clearly visible as possible.
• Replace the bottom panel with a clean, clear pane.
• Use soft, bright light and avoid prolonged direct lighting from a short distance.
• Specify the species, the last molt, and the known feeding range.
• If the key features are obscured, wait for a better opportunity.

What does this mean for husbandry and breeding?

When it comes to daily care, appropriate housing, food portion sizes, and the animal’s condition are more important than determining its sex as early as possible. A mere guess is not enough to pair two animals for breeding.

Only plan a mating with animals that have been reliably identified and are suitable, and after species-specific preparation. That is why jumping spiders are kept separate until then. You can find the relevant guides here for further reading.

Still unsure? Feel free to ask us your question in the comments section below the article.