The Valuable Ecological Roles of Crayfish and the Discovery of Two New Species

We're lucky in the eastern U.S. because bodies of water are pretty common. For most of us, if we don't have access to a creek, stream, river, pond, etc. in our immediate backyards, then we likely have access somewhere nearby in the surrounding community. This means it can be relatively easy for us to explore those waterways, and for many of us part of that exploration at some point included catching crayfish or other aquatic organisms.

In this episode, we talk with Mael Glon, a PhD candidate at the Ohio State University in the Department of Evolution, Ecology and Organismal Biology. Our conversation with Mael focuses on crayfish biology, ecology, diversity, and a variety of other crayfish-related topics.

Although we might think of crayfish as being mostly just a reddish-brown color, that's not always the case. They can also include other colors such as turquois blue, golden yellow, bright red, and mossy green. Some species, especially the burrowing crayfish, can be very showy and absolutely gorgeous.

We can often identify a crayfish species by looking at characteristics like those color patters, the size and shape of the claws, or where the specimen was found. However, for closely related species that look very similar, other characteristics or techniques must be used to accurately identify the species. One of those techniques is to look at the gonopods of the reproductively active males, but while that technique can be very precise, it also has obvious issues.

Crayfish can be considered keystone species in many aquatic and semi-aquatic ecosystems because so many things eat them. However, their importance isn't limited to just being a prey species. Some of our crayfish fall into a group commonly known as the burrowing crayfish. These are the crayfish that burrow underground and often form the mud chimneys that are found around the edges of ponds and streams or in wet meadows. Crayfish burrows are commonly used by a wide variety of animals besides the crayfish that built them.

We have around 400 species of crayfish in North America. The majority of those are in the eastern U.S. and parts of the southeastern U.S. are considered a global hotspot for crayfish biodiversity. Recently, Mael and his colleagues added to this biodiversity by identifying and naming two new crayfish species found in Alabama and Mississippi. Identifying and recognizing new species at the scientific level is important because, when it comes to conservation, one large population of a single species is going to be viewed and managed differently than a population consisting of two or three species, each with much smaller ranges.

Unfortunately, many of us aren't aware of how diverse and special our crayfish populations are. I just think that it's sometimes hard to recognize or appreciate the biodiversity that occurs in our own communities because to us it's "normal" and therefore "nothing special." That's one reason why sharing what we are seeing on platforms such as iNaturalist can be beneficial, because sometimes it takes someone else's eyes and perspective to help us realize just how special something is that we may see every day.

Links:

• Mael's website
• Mael's email: glon.1@osu.edu
• Other resources Mael recommended:
  • iNaturalist Guide to Photographing Crayfish
  • American Crayfish Atlas
  • International Association of Astacology (crayfish research)
• Backyard Ecology's website
  • An Introduction to iNaturalist with Maddy Heredia
• My email: shannon@backyardecology.net

Episode image:

• Banded Mudbug
• Photo credit: Guenter Schuster