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"Sexual harassment" endangers rare Mexican fish


Invasive species have a tendency to kill off native species in their new habitats -- but the method recently observed in Mexican rivers and lakes takes the threat to a whole new level.

The invading species, Trinidadian guppies (Poecilia reticulata), first appeared in Mexico about 50 years ago. While they look pretty darn similar to an endangered native species called Skiffia bilineata, they are not genetically compatible. Nor are their sexual organs compatible. But that doesn't stop the sexually aggressive male guppies from trying to have sex with female Skiffia bilineata -- and harming them in the process.

The problem is that the male guppies like larger females -- and female Skiffia bilineata are larger than the female guppies. As a result, the Skiffia bilineata are getting sexually harassed into extinction, according to research from National Autonomous University of Mexico.

As if being an endangered species wasn't bad enough already...