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Species Description

Crayfish

Cambarus (Hiaticambarus) manningi


Classification

Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Order: Decapoda
Family: Cambaridae

Description

The carapace of Cambarus manningi is dark brown to dark olive in appearance. The abdomen is blue-black and the rear portion of each segment is decorated with a narrow red band. The multicolored tail has a sky blue band across the middle portion, a pale orange rear section and orange to red edges. The chelae (claws) have a distinctive tuft of hair between the "fingers" of each claw. The rostrum is strongly pointed and lacks marginal spines and tubercles (small bumps). The edges of its unique rostrum are bright orange to red in color. The carapace of C. manningi is usually 16-30 mm (0.6-1.2 in) in length.

Life Cycle

There have been relatively few life history studies conducted on crayfish. The available life history data for Cambarus manningi is limited to the form or condition of specimens collected during certain times of the year. First-form (sexually mature) males have been collected during May, September and October. A female carrying young has been collected during May. The life cycle of this species is presumed to be fairly similar to the generalized crayfish life history described below. Based upon the condition of specimens collected during different times of the year, C. manningi copulation is believed to occur between September and May. Copulation involves a sexually mature male crayfish grabbing a female and depositing sperm packages (spermatophores) into the seminal receptacle on the abdomen of a receptive female crayfish. During the appropriate time(s) of year, females secrete a sticky substance on the underside of their abdomen and pleopods in order to attach their eggs. The eggs and sperm (from the seminal receptacle) are then released upon the sticky surface and fertilization occurs. A female carrying eggs on her abdomen and legs is said to be "in berry." Embryos develop and hatch on the underside of females in 2-20 weeks, likely depending upon species and temperature. The immature hatchlings molt (shed their exoskeleton to allow growth) and remain attached to their mother. These first-stage immature crayfish look fairly similar to typical crayfish, but have disproportionately large heads and eyes. Another molting takes place in about 1-2 weeks. These second-stage immature crayfish look even more like adult crayfish. Second-stage or third-stage immature crayfish leave their mother's surface and become independent. These young crayfish continue molting and growing and are usually sexually mature by their second or third autumn. Many adult crayfish die within 3 years of hatching.

Natural History

Adult C. manningi crayfish often hide under rocks in clear streams. This species appears to prefer choppy and moderate to swift-flowing streams. From dusk until dawn, or on very cloudy days, crayfish come out of hiding and search for food in streams. Crayfish are usually omnivorous scavengers, feeding upon whatever is available. Crayfish eat aquatic vegetation, detritus, small fish, aquatic insects and snails. They use their chelae (claws) on their first 3 legs to grab, crush and tear their food. This food is further cut by a number of specialized mouthparts. The main predators of crayfish are fish, frogs, turtles, wading birds, raccoons and humans. Crayfish usually walk slowly across the bottom of their stream habitat using their last 4 walking legs (periopods). When frightened or in danger, however, they quickly escape by "darting" backwards. Crayfish are sometimes found with extensive scaring on their chelae or missing appendages. This occurs while escaping predators or fighting with other crayfish. Male crayfish are especially aggressive with one another and their claw-to-claw combat can be quite intense.

Range

This species is found in streams in portions of the Coosa River Basin in northwestern Georgia , southeastern Tennessee and northeastern Alabama . Within Georgia , this species is found within Chattooga, Floyd and Whitfield counties.

Conservation Status

C. manningi is listed as rare in Georgia . It has a limited range within the state and is threatened by pollution and habitat destruction.

Similar Species

C. manningi is usually distinguished from other crayfish by the beautiful coloration of its tail and abdomen.