What kinds of crayfish might you expect to find in the Ogeechee? With so much aquatic diversity in the basin, what you might see in the upper part of the basin can be completely different from what you might see near the coast. That’s because, even though the river is well connected from top to bottom, the habitats found in the upper part of the basin are completely different from the coastal habitats.
The headwaters of the Ogeechee form on the far extent of the Piedmont (the geographic region separating the coastal plain from the Appalachian mountains) making for clearer and swifter flowing water. But as the Ogeechee slowly snakes its way towards the coast, the water starts to move slower and slower, becoming much darker due to the leaching of tannins. Understandably, these stark differences result in differing crayfish fauna.
In the upper part of the basin, the Variable crayfish (Cambarus latimanus) and the Brushnose crayfish (Procambarus pubsecens) are two commonly found species that are strongly associated with this part of the basin, and are rarely if ever found downstream of Millen, Georgia. The Variable crayfish is one of only a couple of species within the genus Cambarus found within the Ogeechee basin, with the vast majority of other species belonging to the genus Procambarus. This is because, in general, Cambarus species are strongly associated with more rocky streams, like those found in the Piedmont. The Brushnose Crayfish is very similar to other Procambarus species found throughout the basin, with the namesake difference being dense hairs along the rostrum (nose area) of the crayfish.
Some species that can be found in both the upper and lower sections of the basin are the Ogeechee crayfish (Procambarus petersi), Blackwater crayfish (Procambarus litosternum) and Red Swamp crayfish (Procambarus troglodytes). The Ogeechee crayfish, though not common, can be found from the headwaters almost to Savannah. The Blackwater crayfish is incredibly common, and can be found in small streams all over. Chances are, if you’ve seen a small crayfish poking around in a stream in the basin, it was a Blackwater crayfish. The Red Swamp crayfish is one most people are familiar with – it is what people commonly catch for food, and they are easily distinguishable by their large, tubercle-covered red claws.
Lastly, you might see as the Ogeechee is flowing into the ocean would be the Hummock crayfish (Procambarus lunzi), and the Christmas Tree crayfish (Procambarus pygmaeus). Both of these species are more associated with slower, stagnant water; but the Christmas Tree crayfish has one particularly interesting adaptation. The bright colors of the Christmas Tree crayfish are thought to be used as camouflage, as it is almost always found in dense mats of lush aquatic vegetation.
Hopefully this brief introduction to some of the crayfish found within our basin encourages you to get out and explore some of the novelties that make this basin a special place!
(All photos courtesy of Chris Lukhaup and Chris Skelton)