Dimorphic Jumping Spider

The Dimorphic Jumping Spider is less than half an inch in diameter. It is technically known as Maevia inclemens. It can jump up to 50 times its length! These spiders are very jump-happy. They will leap on just about anything they see.

I called the gray male form of this spider a “speckled spider” until we figured out exactly what it was. They have amazing camouflage and can blend right in with their surroundings. All of these photos were from dimorphics that were found on our back porch in Sutton.

The reason these spiders are called “dimorphic” is that the males can come in two different color styles. There is this gray color scheme, called the “gray morph”, and another style that is all black body which is called the “tufted morph”. They look wildly different from each other.  This is one of the only cases in nature where there are two radically different types of males, with very different courtship patterns and looks, but they both mate with single female style.

Even more interesting, whichever type of male the female spider mates with, she ends up having offspring of both colors. However, all the male babies look like the gray style when they are little. It’s only when they molt to their adult form that the tufted ones take on their unique form. I imagine that’s because when they are black, suddenly they are far less camouflaged 🙂


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