Crayfish

(This column was first published in the November 27, 2000 Buffalo News.)

    This had to be the most unusual field trip I had ever joined.

    Dan deRoos of the Fish and Wildlife Service was leading entomologists Wayne Gall and Marc Potzler out onto the Niagara Falls Air Reserve Station fields. I was tagging along as an observer.

    We followed a marshy swale that ran parallel to one of the runways. Cattails and purple loosestrife, now brown, were the common plants growing in the shallow standing water but here and there we found watercress, water plantain and curly dock. Duckweed filled most open water. But we weren't botanizing. Wayne was looking for a species of burrowing crayfish that he had first discovered in this region. He and Raymond Jezerinac had published this 80-mile range extension and now Wayne was looking for additional breeding locations for this unusual species.

    The crayfish I am used to are the kind that you find in streams and along lakeshores. I credit those lake crayfish with my learning to swim when I was only four. I quickly managed an awkward dogpaddle to keep my feet off the mucky lake bottom that I considered infested with those toe-pinchers.

    This species is quite different. It looks much like those other crayfish but it is a homebuilder. It excavates caves that begin above ground but extend down a foot or two below the water table. In those underwater passages burrowing crayfish spend much of their lives, breeding, raising young and remaining protected through the winter. They only venture out to feed on vegetation and to scavenge on living or recently killed tiny animals.

    Every few yards we found evidence of those burrows. Distinctive gray mud chimneys marked the crayfishes' tunnel entrances. These excavation tailings were formed into cylindrical towers about three inches in diameter that rose about the same distance above the surrounding vegetation. Until they were pointed out to me I would never have associated the odd structures with anything living. After we located dozens of these burrows, Wayne picked out what he considered a promising one from which he hoped to capture a crayfish for sure identification. This involved digging out the upper portion of the passage and then roiling the exposed water. This last was supposed to encourage the homeowner to surface -- perhaps to scold whoever was messing up its doorway.

    No luck. Wayne dug deeper, exposing several yards of passageways. More roiling. Still no appearance.

    Finally, just as he was about to give up, Wayne ran his hand through the water and came up with a small crayfish. Unfortunately, this turned out to be still another species, a so-called secondary burrower that will dig its own cave but prefers to live in those constructed by others.

    But one last pass through the opaque water and Wayne grabbed the species we were looking for. Compared with the small crayfish I was used to, this one was a giant. With its big claws it must have been six or seven inches long, to me a small lobster. It was a male but before we left a female also rose to the surface. Never mind those threatening claws. Wayne scooped it up as well.

    We had a wonderful chance to examine these odd arthropods. They belong to the Order Decapoda which signifies ten legs and indeed, counting the big claws they have five pairs. I didn't realize before that three of the pairs have claws, those of the second and third pair tiny compared to the first but like them continuously scissoring open and closed.

    Wayne found this adventure exciting; the rest of us differed: we found it amazing.-- Gerry Rising