Orconectes acares (Fitzpatrick)

Map [dots indicate Ouachita National Forest collection sites]

Recognition Characters: Rostrum with marginal tubercles or spines, median carina present, margins subparallel or slightly converging cephalad, not thickened. Length of areola 29.1 to 33.7 percent of total length of carapace, 5.5 to 7.0 times longer than broad, three to five punctations in narrowest part. Postorbital ridges strong, divergent, corneous spines or tubercles; sides of carapace lacking lateral spines. First pleopod of first form male reaching caudal margin of coxopodite of first pereiopod with abdomen flexed; central projection with strong cephalic shoulder near base; central projection straight, longer than mesial process, setiform and straight almost to tip; mesial process, slender, with tip curving caudodistally; mesial process straight, setiform, slender, delicate; tips of first pleopod divergent and bent mesiad near tip. Chela depressed but palm somewhat inflated; all surfaces bearing setiferous punctations.

Coloration: Body color slate-gray with telson and uropods fuscus. Chela slate gray with undersides off-white. Body color off-white to pinkish. Distinctive dorsolateral paired bright red spots on tergal segments three, four, and five. A red bar runs across tergal segment six. Cheeks and lower edge of the gill cover with pinkish streaks.

Size: Adults are about 1 to 3 inches (25-76 mm) in total length.

Habitat: This stream dwelling species inhabits rapidly flowing water on or near shoals of streams as well as in spring out-flows.

General Range: Arkansas endemic (Robison and Allen, 1995).

Range Within Arkansas: Hobbs (1989) presented the range of Orconectes acares as the tributaries of the Ouachita River in Garland, Hot Springs, Montgomery, Perry, Pike, Polk, and Saline counties, Arkansas.

Comments: The type locality of this state endemic species is a stream tributary to the Ouachita River six miles (9.6 km) northwest of Mount Ida, Montgomery County, Arkansas (Fitzpatrick, 1965; Robison and Allen, 1995).

Orconectes acares was collected at 125 of the 251 sites in Arkansas during the study for a total of 1,258 specimens. This Ouachita River endemic has its distribution centered within the ONF and thus its high abundance should be expected. Together with Procambarus palmeri longimanus, O. acares is one of the two most abundant crayfish species on the Arkansas portion of the ONF.

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