February, 2017

Red Swamp Crayfish

Not many crustaceans can show up in our backyard ponds, but one can and did. The red swamp crayfish (Procambarus clarkii) is an extremely adaptive species that can survive in even marginal habitats. It grows rapidly and can live for over 2 years. This is the crayfish most often raised commercially for food, especially in Louisiana. While it is usually red, it can also have a bluish cast to its shell. It is native to our area, but has been introduced in other places in the U.S. and also in Asia, Africa, South America and Europe, where it is often considered an invasive species.

During wet weather, individuals may wander long distances over land, sometimes as far as several miles in a few days. These are burrowing crayfish and dig deep holes in mud next to ponds or other water sources, usually down to the water table, as, despite their penchant for terrestrial travel, they are aquatic and breathe through gills. One that lived in our pond during a summer did construct a burrow, but it couldn't adapt to the fact that the pond has a lining and so it never reached water. I think the burrow simply went under the pond, where the animal could stay cooler and somewhat moist during the hottest weather. Otherwise, it had to periodically return to the pond through the entrance to its retreat. One characteristic of this species is that they alternate periods of sexual activity and inactivity, so eventually our yard crayfish got the urge to move on, very likely because it was all by itself and had no mate. However, it wasn't as successful at finding a way out as it had at getting in. I found it dead in a corner by the fence.