97: Razorback Sucker

I write to you from Arapahoe, Ute, and Cheyenne land. I am interested in learning about the different animals that live in the place where I was born. Before we start with today’s animal, I want to emphasize that biological classification as understood by western society has its roots in racism, sexism, and transphobia – here’s a good explainer about why.

Three to five million years ago, this strange looking fish swam into the Colorado River and began to move throughout its tributaries. This fish is notable for its enormous humped back that rises above its relatively narrow head. Today the fish is endangered throughout the Colorado Basin, especially below the Grand Canyon; ironically, the only places that have a population of the fish that does not have to be supplemented by stocking are Lake Mojave and Lake Mead, two artificial lakes in the desert. I say ironically because the creation of dams on the Colorado River and the destruction of river habitats are why these fish, like so many others we’ve talked about here, are now endangered.

 The Razorback is the only species in its genus, Xyrauchen. They can live to be 40 years of age! They also have an interesting adaptation of their eye. From a paper by Flamarique et al. (2007):

“Body reflections in the ultraviolet (UV) are a common occurrence in nature. Despite the abundance of such signals and the presence of UV cones in the retinas of many vertebrates, the function of UV cones in the majority of taxa remains unclear. Here, we report on an unusual communication system in the razorback sucker, Xyrauchen texanus, that involves flash signals produced by quick eye rolls. Behavioural experiments and field observations indicate that this form of communication is used to signal territorial presence between males.”