Fallicambarus harpi (Hobbs and Robison)

Map [dots indicate Ouachita National Forest collection sites]

Recognition Characters: Body subovate and somewhat compressed although branchiostegites somewhat inflated. Abdomen much narrower than cephalothorax. Greatest width of carapace distinctly posterior to caudodorsal extremity of cervical groove and greater than height. Areola linear over much of its length. Rostrum with convergent moderately thickened margins, contracting anteriorly forming short triangular acumen, apex of which corneous, slightly upturned, and extending just beyond base of penultimate podomere of antennular peduncle. Dorsal surface of rostrum concave with submarginal row of setiferous punctations and few scattered ones between. Cervical spine lacking. Carapace punctate dorsally and laterally. Branchiostegal spine represented by slight obtuse prominence at lower anterior extremity of cervical groove. Abdomen shorter than carapace. Pleura very short and rounded. Cephalic section of telson without spines. Chela about 1.7 times as long as broad, strongly depressed. Mesial margin of palm little less than half width of palm and bearing row of seven tubercles subtended laterally by row of five smaller ones. Male with hook on ischium of third pereiopod only. First pleopod of first form male almost straight and bearing small or well-developed caudidistally directed cephalic process. Mesial process barely or weakly curved and directed caudally. Central projection strongly arched with apex directed proximally. Coxa of fourth pereiopod of male with very strong compressed boss with rounded ventral margin.

Coloration: The dorsum of cephalic region of carapace, including rostrum, is very dark, almost black, that of thoracic region being greenish tan except for a small black triangular spot in the open anterior section of the areola. A narrow band borders the cervical groove, and there is another band adjacent to the posterior margin of the carapace. Hepatic and mandibular adductor regions are black. The orbital, antennal, mandibular, and branchiostegal regions are greenish tan. The abdomen has a broad median longitudinal, dark red stripe extending from the second through the fifth segment, which becomes pale and disappears before reaching the caudal margin of the sixth segment. Uropods are greenish tan with dark markings. The dorsal surface of cheliped is dark green with a black suffusion which becomes intense mesially.

Size: Largest known specimen is a female with a carapace length of 39.6 mm (postorbital carapace length 35.8 mm).

Habitat: Low-lying seepage areas in pastures, yards, and lawns.

General Range: This is another state endemic crayfish whose range was recently better elucidated by Robison (2000) to include Pike, Hot Spring, Montgomery and Garland counties, Arkansas.

Comments: This Arkansas crayfish was the subject of a status survey recently and it has proven to have a larger range in Arkansas than previously believed (Robison, 2000). It was collected four times in 2000 on the ONF in Arkansas.

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