Saturday, March 12, 2016

Springtime Crayfish Happiness

Okay, here’s a real “Opulent Opossum” subject for you: the glory of crayfishes in early spring! Plus, the Missouri Department of Conservation has just published a new booklet to help you learn to identify our state’s 36 crayfish species!

Chris Riggert, the Volunteer Water Quality Monitoring Coordinator for the Conservation Department’s Stream Team program, headed up the project. The new booklet is an excellent introduction for identifying the state’s crayfishes—a good “jumping in” place to get you started in learning about (and thus appreciating) our beloved crawdads.

I love to see rocky creeks come alive in early spring.

In early spring, with the leaves still off the trees, light penetrates through the bare branches of the forest canopy and shines on the creekbeds. This light creates a short-lived “bloom,” first, of a matlike brown algae (I think it’s a diatom), and then of a wispy filamentous green algae—like flowing green tresses, wafting in the current. That algae is to creeks what bloodroot, trilliums, and spring beauties are to the springtime forest floor.

And though the water’s pretty cold, it’s no longer frozen, so the animals start getting active. I have spent hours and hours by streams, watching the snails crawl around on the rocks, minnows glide and dart hither and thither, and crayfish explore the miniature aquatic caves and canyons.

It’s our midcontinent version of tidepooling, and it’s a fun as all get-out.

Last weekend, when we had some really nice weather, Sue and I visited Clifty Creek Conservation Area (which is fast becoming my favorite hikin’ place; click here for the MDC web page on it).

When we were there, we saw lots of golden crayfish (Orconectes luteus) scooting around in that crystal clear water. They were nearly all about one and a half inches long.


One of the things that the new MDC brochure (and their other printed crayfish publications, and the online Missouri field guide) emphasize is that crayfish identification involves more than just colors, spots or stripes, and body shape. First, you narrow your search by habitat and geographic range.

Although a handful of our crayfishes are found nearly everywhere, most are restricted to certain parts of the state, and certain watersheds within those regions.

Some crayfish species occur only in the glaciated and unglaciated plains of north and northwest Missouri, where they live in streams that are rather sluggish and turbid, or where they tunnel clear down to the water table in prairies. Others occur only in the Ozarks, where the streams tend to be clear, brisk, cool, and rocky. And others are found (in our state) only in the Bootheel, where swamps and ditches prevail.

And within those broad ranges and habitat types, many crayfish species are confined to certain particular river drainages. An example is the Neosho midget crayfish, which occurs only in the Spring River and Elk River systems, so in our state, you probably won’t find it anyplace besides our far southwestern corner.

So if you want to identify a crayfish, first, identify the region, habitat, and watershed, and then start looking at the color, the spots or stripes, and peculiarities of pincer shape and so on. The new brochure organizes our crayfishes by location: Ozarks, Prairie, Lowland (Bootheel), and Statewide, and each entry has a distribution map showing watersheds, which helps you immediately narrow down your search.

This, by the way, is the same situation when you’re trying to identify fish, particularly minnows and darters, which are also numerous and diverse—unless you know where they’re from, they can be kind of a pill to identify to species.

I love being able to identify plants and animals. It’s not so much that knowing the name has some kind of magic (though it helps me remember)—it’s that the process of identifying forces me to look, really look, at the organism, and see things I might not notice before. That’s the value; that’s the fun.

For example, did you know that one of the keys to identifying crayfish can be the shape of the rostrum? Crayfish bodies are quite different from ours, so you have to learn a little “Crayfish Anatomy 101.” The rostrum is the triangular little beaklike structure between the eyes. It’s shaped differently in different species of crayfish—pointier or less pointy, long or stubby, ridged or furrowed (or furrowed with a little ridge within), with or without spines flanking the tip . . . Isn’t that fascinating? Now, you can really see it!

Anyway . . . these and many other thoughts pass through my mind as I peer into a creek like Clifty, watching the crayfish explore like little armored vehicles among the rocks and crannies. Crayfish happiness!

It’s my happiness, too.

Do you want a copy of this nifty booklet? It’s hot off the presses, so it hasn’t been promoted much yet. Send an e-mail to, and ask for A Guide to Missouri’s Crayfishes FIS011.”