Cross River Crawdaddies

Decapoda use their tails to scoot backwards underwater. This one actually back-jetted into Karl’s hands. (It was returned unharmed, if discombobulated by all the media attention.)Cross River, running through Ward Pound Ridge Reservation, is a-crawling with crayfish. This was one of the smaller ones. The others were much less red. Perhaps this one had just molted? Or was it another species entirely?This larger specimen was using its dainty feeding appendages to scoop up tiny bits of decomposing plant and animal material.A goner. Note absence of claws. This view gives us a good look at the four pairs of walking legs, the little paddles (swimmerets) under the tail, and all that maxilliped business around the mouthparts.This crawdaddy may have found the day drawing to a close much more quickly than anticipated

In this 1957 monograph, there were 8 known New York State species. Skimming this, we learn that males come in two forms. And that, like quite a lot of other invertebrates, the surefire way of telling some species apart is by examining their sex organs. More recent study shows they are heavy metal accumulators and have been used to measure such poisons in watersheds.

From the archives: a Prospect Park encounter with a crayfish.