https://phys.org/news/2018-05-male-variant-bulb-mite.html

Until now, male bulb mites have been known to display two discrete reproductive tactics: fighters and scramblers. Fighters have a thickened and sharply terminated third leg pair than can be used to fight and kill other males, while scramblers have no such armaments. "Surprisingly, during our experiments we kept noticing males that are morphologically similar to females, with a large body, bulbous abdomen and slim third leg pair," says Stewart. "We named this variant the 'mega-scrambler.'"

The bulb mite is widely used as a model organism for studying alternative reproductive tactics (ARTs). "Which makes it even more surprising that this third male morphology, or 'trimorphism," has not been noted before. It was important for us to describe this new type of ART because it has important implications for our understanding of how organisms adapt to rapidly changing environments and population dynamics, but also because we want to encourage others to not overlook model systems that are thought to be completely described."