Crustaceans

Crayfish in Glass Bayou

NPS Photo

 

There is one "crustacean sensation" that is well known up and down the southern reaches of the Mississippi River, and that is the crayfish. Vicksburg is no exception. The park's streams hold an abundance of these creatures that look somewhat like miniature lobsters. (Just don't be surprised when you get a blank look from the locals when you mention crayfish. In this part of the country they are much better known as "crawfish", "crawdads", or even "mudbugs"!) Done up "Cajun style", crayfish are a regional delicacy. However, the crayfish found on menus and at roadside stands during the spring months are seldom wild-caught; most likely they have been farm-raised en masse in aquaculture ponds.

While the crayfish inhabiting the park's waterbodies have little fear of ending up in an etouffe, they are part of a functioning aquatic ecosystem and may become prey to birds, turtles, fish, or even baby alligators. This is especially true during the days immediately after molting. When the crayfish molts it sheds its hard exoskeleton, which allows its soft living tissue to enlarge. In this way the crayfish grows, but is temporarily vulnerable while its new exoskeleton is hardening.

To gain strength and continue growing the crayfish will feed on snails, algae, insect larvae, worms, tadpoles, and fish eggs. They hunt mostly at night. One of the adaptations crayfish have evolved for capturing food (as well as defending itself) is a pair of relatively large pinching claws, known as chelipeds. These, along with its stalk-mounted eyes and muscular tail (or abdomen), are what make the crayfish a distinctive-looking animal.

Crayfish are relatively simple animals. They breathe through gills, and if they happen to lose an appendage it will regenerate itself. But simple certainly doesn't mean unsuccessful. Crayfish, and its relatives in the class of animals known as crustaceans, belong to one of the oldest and most diverse groupings of animals- the phylum arthropoda. Along with insects and spiders, the crayfish is a well-adapted animal indeed.