23: Brassy Minnow

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. I want to mention that biological classification as taught by western science has its roots in racism, sexism, and transphobia – here’s a good explainer about why.

Today’s animal is a fish, the Brassy Minnow (Hybognathus hankinsoni). While reading about this fish, I learned that there are different names for the different orientations of mouths. For example, this little guy has a “small subterminal mouth” which means that the mouth points slightly downward, with a bit of an overbite, because the upper part of the jaw is longer than the lower. Mouth shape is a function of how the fish feeds, with subterminal mouths often found in bottom-feeding species. I guess that before reading about this, I had never thought about fish mouth shape, and one google image search later, I am really thinking about it!

The Brassy Minnow lives in prairie streams throughout much of the interior of North America, with central Colorado being the southern limit of its range and parts of Alberta and British Columbia being the northern part. They also like to live in beaver ponds – in fact one of the major ways to conserve this fish is to encourage beavers to move into an area.

Brassy minnows like to munch on plankton. Reading about them, I kept reading that they “do best where there’s low predation” which, uh, makes sense to me, but apparently is a reasonable way of describing fish as I guess these guys are particularly susceptible to predators, especially the northern pike and the walleye.

Tomorrow we have got a really fascinating mammal…