Cambarus coosawattae Hobbs 1981

Cambarus (Hiaticambarus) coosawattae Hobbs

Cambarus (Hiaticambarus) coosawattae Hobbs, 1981:150, figs. 22b, 58a, 59, 60, 207.

TYPES.—Holotype, allotype, and morphotype, USNM 148112, 148113, 148114 (male I, female, male II); paratypes, USNM.

TYPE LOCALITY.—Cartecay River, 6 miles (9.6 km) east southeast of Ellijay, just off Route S1010, near Flint Hill Church, Gilmer County, Georgia.

RANGE.—Known only from the Coosawattee watershed (Coosa River basin) in Gilmer County, Georgia.

HABITAT.—Streams (primarily riffle areas).

Cambarus (Hiaticambarus) coosawattae

Cambarus (Cambarus) extraneus.—Ortmann, 1931:98*.

Cambarus longulus.—Anonymous, 1967a, tab. 3.

Cambarus (Hiaticambarus) species G.—Hobbs, 1969a:106, 141, fig. 10* [in part].

The first record of the occurrence of this species is that of Ortmann (1931), which was based upon two second form males from the Cartecay River, East Ellijay, Gilmer County, Georgia. As indicated above, he erroneously identified these specimens as Cambarus (C.) extraneus. Anonymous (1967a) recorded this crayfish as C. longulus from the Coosawattee River, 2 miles south of Ellijay at State Route 5, Gilmer County. The distribution map provided by Hobbs (1969a) for his “species G” encompasses the ranges of two species of the subgenus (both described herein: C. (H.) coosawattae and C. (H.) fasciatus), as do the references to it on pages 106 and 141. No specific localities were cited by him.

DIAGNOSIS.—Rostrum with strongly tapering margins bearing small spines or tubercles (sometimes abraded in individuals in late intermolt stage) at base of acumen. Postorbital ridge terminating cephalically in spine. Cervical spine and suborbital angle obsolete. Areola 2.8 to 4.0 times as long as broad and comprising 34.8 to 37.8 percent of entire length of carapace (41.8 to 44.3 percent of postorbital carapace length). Chela with tubercles along mesial margin of palm adpressed, more distal ones sometimes virtually lacking, always with conspicuous setal tufts at mesial base of fixed finger; lateral margin of propodus costate or subcostate. Hook on ischium of third pereiopod opposed by tubercle on basis. Pleura of third through fifth abdominal segments truncate ventrally and with caudoventral angle. First pleopod of first form male with moderately short terminal elements: central projection bearing distinct subapical notch, not tapering, and directed at about 120 degrees to shaft of appendage; mesial process inflated, tapering, with acute tip directed caudally at about right angle. Terga of abdomen with narrow, dark marginal band posteriorly, first with slightly paler transverse band across midlength, and pleura lacking scalloped stripe at base. Female with first pleopod present.

HOLOTYPIC MALE, FORM I.—Body subovate, depressed (Figure 59aj). Abdomen narrower than cephalothorax (10.8 and 12.5 mm); maximum width of carapace markedly greater than depth at caudodorsal margin of cervical groove (12.5 and 9.4 mm). Areola 3.9 times as long as broad, constituting 36.6 percent of total length of carapace (44.2 percent of postorbital carapace length), densely punctate with about 9 punctations across narrowest part. Rostrum with thickened margins converging strongly to base of acumen, there subangular and bearing small corneous tubercles; acumen with strongly upturned tip, reaching end of basal third of ultimate podomere of antennular peduncle; dorsal surface of rostrum weakly concave and bearing crowded, deep punctations, those in basal portion coalescing into striae. Subrostral ridges rather strong but evident in dorsal aspect only posterior to acumen. Postorbital ridge short, grooved dorsolaterally, and terminating cephalically in acute spine. Suborbital angle obsolete; branchiostegal spine reduced to subacute tubercle. Cervical spine lacking, not even represented by tubercle. Carapace densely punctate dorsally except for polished median gastric area and that interrupted by 2 or 3 punctations, lateral surface mostly granulate but tubercles present in ventral hepatic, antennal, and mandibular regions and flanking cervical groove in anteroventral branchiostegal area. Abdomen shorter than carapace (23.3 and 24.6 mm); pleura moderately long, truncate ventrally, and angular posteroventrally. Cephalic section of telson with 2 spines in each caudolateral corner, usual lateral incision deep and transverse suture clearly defined. Uropod with both lobes of proximal podomere bearing corneous spine; mesial ramus with distolateral spine and poorly defined submedian ridge ending in distomedian spine.

Cephalomedian lobe of epistome (Figure 59g) subtriangular, central area somewhat elevated, lacking cephalomedian prominence; main body with distinct fovea and arched epistomal zygoma, latter flanked anterolaterally by deep elongate pits. Ventral surface of proximal podomere of antennular peduncle with short acute tubercle very near distal end. Antennal peduncle with strong lateral spine on basis and with subacute corneous tubercle on ventral surface of ischium; flagellum reaching sixth abdominal tergum; antennal scale (Figure 59i) about 2.8 times as long as broad, widest along area contiguous to midlength, distolateral spine strong and reaching distal margin of antennular peduncle. Ventral surface of ischium of third maxilliped with broad longitudinal band of both stiff and plumose setae and with submarginal lateral row of smaller stiff and plumose ones; irregular row of punctations bearing short plumose setae between band and submarginal row; distolateral extremity subacute but not produced.

Right chela (Figure 59l) 2.2 times as long as broad, mesial margin of palm occupying about one-third its length. Mesial surface of palm with single row of 8 adpressed tubercles flanked dorsally by row of punctations; dorsal and ventral surfaces with large, deep punctations, and palm subcostate distolaterally. Fingers moderately widely gaping and with prominent setal tuft protruding into gap from proximal half of opposable margin of fixed finger; deep punctations and depression flanking subcostate lateral margin of finger, setting off well-defined median longitudinal ridge on dorsal surface of finger; opposable margin with row of 9 rounded tubercles along proximal two-thirds of finger and single large tubercle on lower level between seventh and eighth of row; band of minute denticles extending distally from proximal base of large tubercle to corneous tip of finger; opposable margin of dactyl with row of 11 tubercles along proximal four-fifths of finger and band of minute denticles, interrupted by tubercles, extending from sixth tubercle from base to corneous tip of finger; median longitudinal ridge on dorsal surface not so prominent as that on fixed finger; mesial surface of dactyl punctate.

Carpus of cheliped with well-developed longitudinal furrow dorsally, flanked by setiferous punctations; mesial surface with large spikelike tubercle, lacking more proximal tubercle present in some other members; ventral surface punctate and 2 tubercles present on distal margin, 1 on lateral condyle and other on mesioventral angle. Merus with 1 premarginal tubercle dorsally; ventrolateral row of tubercles represented by only 2, and ventromesial row consisting of 7 (left member with 6), all acute, and distal members of both rows spikelike; distolateral surface with minute corneous tubercle. Mesial margin of ischium with 2 small tubercles.

Ischium of third pereiopod with simple hook overreaching basioischial articulation and opposed by strong tubercle on basis (Figure 59h). Coxa of fourth pereiopod with transverse boss vertically disposed, that of fifth pereiopod devoid of boss but with ventral membrane sparsely setiferous.

First pleopods (Figure 59b,d,f) reaching coxa of third pereiopod, symmetrical, with gap between their bases. (See “Diagnosis” for description.)

ALLOTYPIC FEMALE.—Excluding secondary sexual characters, differing from holotype in following respects: flagellum of antennae reaching fifth abdominal tergum, antennal scale broadest distal to midlength; mesial margin of palm of chela with adpressed row of 9 tubercles on right chela and 7 on left; opposable margin of fixed finger with row of 7 tubercles along basal two-thirds and large tubercle on lower level between sixth and seventh tubercles from base; corresponding margin of dactyl with row of 9 tubercles; mesial surface of carpus of cheliped with small tubercle proximal to large spikelike one; 6 tubercles present in ventromesial row on merus; mesial margin of ischium with 3 small tubercles. (See “Measurements.”)

Annulus ventralis (Figure 59k) approximately 1.5 times as broad as long, slightly movable, subsymmetrical, cephalic and central areas less sclerotized than caudal part; cephalic area with subparallel longitudinal ridges flanking median trough leading to depressed central area; sinus originating at caudal end of trough, from there extending dextrally, making hairpin turn, to median line before turning rather sharply and forming arc slightly sinistral to median line, returning to latter on caudal wall. Postannular sclerite with straight caudal margin and broadly arched cephalic margin, almost one-third as long and little less than three-fourths as wide as annulus. First pleopods reaching midlength of annulus when abdomen flexed.

MORPHOTYPIC MALE, FORM II.—Differing from holotype in following respects: margins of rostrum continuous with base of acumen, lacking angle but with minute tubercle marking position of angle in other specimens; branchiostegal spine vestigial; ischium of antennal peduncle on right side lacking small acute tubercle (injured?), flagellum reaching fourth abdominal tergum; opposable margin of fixed finger of right chela with row of 8 tubercles (left cheliped regenerated), that of dactyl with 10; mesial surface of carpus with small tubercle proximal to spikelike one; ventromesial surface of ischium with 4 tubercles; hook on ischium of third pereiopod much reduced, not overreaching basioischial articulation. First pleopod (Figure 59c,e) with juvenile suture on shaft; central projection inflated with subacute apex directed caudally at right angle; mesial process little different from that of holotype.

COLOR NOTES (Figure 58a).—Entire body basically pale olive to brown with darker olive to dark brown reticulations on mandibular adductor region and dark brown cervical groove; posterior margin of carapace and corresponding margin of all abdominal terga with narrow band of burgundy; rostral margins and postorbital ridges orange to vermilion; antennal and mandibular regions pinkish cream; telson and uropods pale olive to brown with orange to vermilion spines and spots on proximal podomere of latter; basal podomeres of all pereiopods cream to midlength of ischium, from there distally pale to dark olive and with orange to vermilion articular margins, knobs, spines, and tubercles.

Measurements (mm)

TYPES.—The holotypic male, form I, allotypic female, and morphotypic male, form II (numbers 148112, 148113 and 148114, respectively), are deposited in the National Museum of Natural History, Smithsonian Institution, as is the paratypic series, which is restricted to those specimens listed from localities 1–4, 8, and 9 under “Specimens Examined.”

TYPE-LOCALITY.—Cartecay River, 6 miles east southeast of Ellijay, just off Route S1010, near Flint Hill Church, Gilmer County, Georgia. There the stream, some 17 meters wide and less than 1 meter deep, flows with a swift current over a sandy, rock-littered bottom. The water is clear and shaded along the margins of the stream by Liriodendron tulipifera, Plantanus occidentalis, Quercus sp., and Prunus sp. Only one other crayfish, C. (J.) conasaugaensis, was found in company with Cambarus (H.) coosawattae.

RANGE.—This crayfish is known only from the Coosawattee watershed (Coosa River basin) in Gilmer County, Georgia. Although a number of crayfish collections are available from the same watershed in Gordon and Pickens counties, no members of C. (H.) coosawattae were among them.

GEORGIA SPECIMENS EXAMINED.—I have examined 187 specimens from the following localities. Gilmer Courtly: (1) type-locality, 4II, 3III, 6, 23 Oct 1976, T. A. English, Jr., HHH, collectors; (2) Little Turniptown Creek 7.3 mi SW of Fannin Co line on US Hwy 76, 1I, 1II, 1, 1j, 16 Apr 1962, J. F. Fitzpatrick, Jr., HHH; (3) trib to Ellijay River 5.4 mi N of Ellijay on US Hwy 76, 5I, 4, 5j, 1j, 10 Oct 1969, K. R. Martin, HHH; 2I, 1, 21 Sep 1972, HHH; (4) Rock Creek 8 mi NE of Ellijay, 1II, 1, 1j, 3 Sep 1953, R. H. Gibbs, Jr., et al.; 1I, 9 Oct 1955, R. W. Yerger et al.; 13I, 13II, 17, 1j, 4 ovig , 28 Apr 1967, Torgny Unestam. HHH; (5) Cherry Log Creek just W of Fannin Co line on US Hwy 76, 2II, 1, 8 Sep 1945, G. B. Hobbs, HHH; 2I, 1j, 1j, 28 Apr 1967, TU, HHH; (6) trib to Cherry Log Creek 7.9 mi NE of Ellijay on US Hwy 76, 1I, 2II, 1, 1j, 8 Sep 1945, GBH, HHH; (7) Conasauga Creek 9.7 mi NW of Ellijay on US Hwy 76, 2I, 18II, 17, 2j, 3j, 6 ovig , 16 Apr 1962, JFF, HHH; (8) Cartecay River 3.0 mi SE of Ellijay on St Rte 52, 1I, 1j, 1 ovig , 22 Apr 1968, C. R. Gilbert et al.; 1II, 3, 15 Aug 1970, F. J. Schwartz et al.; (9) Cartecay River 1 mi N of Cartecay on St Rte 52, 2, 1j, 1j, 23 Jul 1960, A. L. Metcalf; (10) Hells Creek on secondary road between St Rtes 5 and 156, 2j, 2 ovig , 28 Apr 1967, TU, HHH; (11) Coosawattee River 2 mi S of Ellijay on St Rte 5 (Anonymous, 1967a, tab. 3), 2j, 1j, 29 Jul 1966, L. Carrick.

Accurate locality data are lacking for 1I, 4II, 2, 11j, 5j, and 2 ovig collected in June.

VARIATIONS.—In all of the specimens examined, except those from Little Turniptown Creek, the rostral margins are strongly convergent; in the few specimens available from this stream, however, the rostral margins are not strongly inclined anteriorly toward the median line and resemble the rostra of C. (H.) fasciatus; otherwise the crayfish from there are typical of C. (H.) coosawattae. In the specimens from Hells Creek, there are as many as 13 punctations across the narrowest width of the areola. In many of the crayfish, especially those in the Ellijay River watershed, the ventral surface of the ischium of the antennal peduncle does not bear a well-defined spine, and indeed in a number of them the podomere is conspicuously reduced in size. Prominent tufts of setae may or may not be present at the opposable base of the fixed finger of the chela. In any part of the range, the mesial surface of the carpus of the cheliped may or may not have a small tubercle proximal to the major spikelike one, and the ventral surface of the merus rarely has three tubercles in the lateral row, but the mesial row has from five to 13.

Except for these features, there are no conspicuous variations that exceed the ranges pointed out in the descriptions of the primary types and that are apparent in “Measurements.”

SIZE.—The largest specimen available is a second form male having a carapace length of 34.5 (postorbital carapace length 28.9) mm. Corresponding lengths of the smallest and largest first form males and of the smallest ovigerous female are 19.4 (16.2) and 34.1 (28.7) mm, and 22.1 (18.2) mm, respectively.

Cambarus coosawattae, the Coosawattae crayfish, is a species of crayfish in the family Cambaridae. It is endemic to Georgia. The common name refers to the Coosawattee River, with the original specimens being collected in the Cartecay River which combines with another river to form the Coosawattee.

The IUCN conservation status of Cambarus coosawattae is "NT", near threatened. The species may be considered threatened in the near future. The population is stable. The IUCN status was reviewed in 2010.