Interactions

The Hell Creek Crayfish is an opportunistic omnivore, eating nearly anything that it is able to. Little is actually known about the diet of the crayfish, but there are confirmed populations of ozark cavefish, rock bass, lucifuga, sculpins, central stonerollers, and other crayfish in both of the caves (USFWS, 2006). Fish eggs are a favorite for crayfish, and are a likely food source for them. Crayfish are detritivores, and will consume the decaying matter of other organisms, so scientists believe it is likely that much of their diet comes from consuming fish after they die. Crayfish also eat plant matter, so any vegetation in the cave may also be a viable source of nutrition. The hole that was drilled for mining actually is beneficial to the ecology of the area now because it allows organic matter such as leaves and small organisms to fall into the deeper regions of the cave where food is less common (Graening et al. 2006). Grey Bats used to inhabit the cave and one of the primary sources of food for the crayfish was the feces from the bats that fell into the water. But due to some ecological changes, the bats have left the cave, and taken important nutrients with them. Scientists are trying to figure what caused the bats to leave, and want to reverse it to bring them back to Hell Creek Cave (IUCN, 2010).

 When hunting for food, crayfish use their powerful pincers to capture and crush prey. They can wound or kill many organisms, such as worms, insects, or other smaller crayfish. They also use their pincers to rip off matter from dead plants or animals. Being such a small animal, the Hell Creek Cave Crayfish is near the bottom of its food chain. The cave has an open entrance, and small mammals such as raccoons and opossums can enter and hunt for the crayfish. Also, some of the rock bass get to be over 8 inches in length and love to feed on the tiny crustaceans. 

With so many potential predators, crayfish have developed many methods of defense. Although they have no pigments and appear to be white, camouflage and hiding is the primary way crayfish avoid predation, as they will hide under rocks, or dig small burrows. If a predator sees a crayfish, they swim backwards quickly while simultaneously flinging mud at the threat to try to escape. They can use their pincers to try to pinch and fight the attacker but this is not very effective against larger predators. One of the most distinguishing traits of crayfish is their hard exoskeleton made of chitin. This shell helps protect them, but it can also be very dangerous because the crayfish need to molt in order to grow. When the crayfish molts, it is vulnerable during the process, and also after because the new shell is soft, so the crayfish needs to choose an appropriate time and place to molt.

Although the crayfish is not blind, most troglofauna rely very little on eyesight because it is so dark in their environmnent. Organisms have developed amazing sense of hearing and chemo-receptors, along with other sensory devices. Many people know that bats use echo location to find their food, and other organisms can use their sense of smell. The Blind Cave Fish uses an enhanced sense of smell, taste, and feel. It is truly amazing what evolutionary paths these isolated cave dwelling organisms can follow. 

 
Parasites and other microbial issues have not been extensively studied yet, but in other species endemic to caves, the transfer of parasites from organism to organism is possible due to their close proximity (USFWS, 2006). This is the reason it is common practice for cave divers to completely disinfect their equipment before entering, attempting to prevent the introduction of new parasites into the environment.

 
Humans have not typically used the Hell Creek Crayfish because there is such a small population of them, but humans do use other crayfish for a variety of food and activities. In the south (US), crayfish boils are very common, and they are considered a delicacy. They are also used for bait because bass and other fish are so attracted to the meat, and many lures are made to resemble the crayfish. Ecologically, they are great indicators of water purity because they are so sensitive to pollutants, and they also help clean up their environment by eating dead and rotting matter. The Hell Creek Crayfish is a very interesting organism, but we don’t know enough about it, and its network of relationships. There is ongoing research, and plans in place to protect this delicate animal, so hopefully we can learn more in the future.