Orconectes (Procericambarus) theaphionensis (Decapoda: Cambaridae), the sinkhole crayfish, a new species of crayfish from southcentral Indiana.

ABSTRACT. A new species of crayfish Orconectes (Procericambarus) theaphionensis is described from southcentral Indiana in the karst areas of the Lost River and Blue Creek drainages. The species occurs both above and below the Orangeville Rise and in Stampers Creek. The species is distinguished from other recognized members of the subgenus by its strong carina, rostrum deflected, non-serrate mandible, broad carapace, presence of setae just posterior to the cervical groove and the anterior portion of the areola, and distinct chelae tubercle formula. The rostrum is concave dorsally, terminating in an upturned acumen, median carina strong. Rostral margins thickened; edges distally converging providing a slightly convex appearance; terminating in spines. The dactyl formula ranges from 0, 4-8, I, 3-4 (5), while the propodus formula is 0, i, 3-6, I, (2) 3-4. The central projection diverges from the mesial process and the central projection length to total length of pleopod (mean = 44.86%, range = 34.4-56.3%) is intermediate between Orconectes cristavarius and O. putnami. Of the recognized members of the subgenus Procericambarus, it is most similar to Orconectes (P.) juvenilis, which is found in southeastern Indiana and Kentucky. The new form can be differentiated from O. (P.) juvenilis by the presence of a strong median carina, the suborbital angle obsolete, and a divergent central and mesial projection that is greater than 35% central projection length to total length of pleopod.

Keywords: Taxonomy, Procericambarus, Cambaridae

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Taylor (2000) diagnosed the Orconectes juvenilis complex and provided empirical data that elucidated the taxonomic status of members of this group. The group belongs to the crayfish subgenus Procericambarus (Fitzpatrick 1987), which possesses a strong angular shoulder on the cephalic surface at the base of the form I male pleopod's central projection, the central projection accounting for at least 35% of the total pleopod length. The Orconectes juvenilis complex as described by Taylor (2000) includes six species. Hobbs (1972) and Bouchard (1976) included in the complex, Orconectes juvenilis (Hagen 1870), Orconectes spinosus (Bundy 1877), and Orconectes putnami (Faxon 1884), while Taylor (2000) added Orconectes rusticus (Girard 1852), Orconectes ronaldi Taylor 2000, and Orconectes cristavarius Taylor 2000. All six species are native in the unglaciated Interior Plateau region of Kentucky, Indiana, West Virginia, and Ohio, and inhabit rocky streams and rivers.

During studies of the crayfish fauna of Indiana, the senior author has found several new crayfish species of the Procericambarus subgenus. The recent taxonomic diagnosis by Taylor (2000) has provided an opportunity to reduce the complexity of this group and validate other closely related taxa. Faxon (1885) recognized extreme variation in character state combinations of species later assigned to Procericambarus; while Hagen (1870), Ortmann (1931), and Faxon (1884) recognized varieties of O. rusticus and various combinations of synonymized species within O. juvenilis.

Here we examine the morphological variation within an undescribed member of Procericambarus occurring in Indiana. As the southern unglaciated portions of Indiana are analyzed, character states necessary for distinguishing species boundaries will likely provide information necessary for description of additional new species in the Procericambarus complex.

METHODS

Specimen measurements follow Taylor (2000), with the exception of a formula we develop for describing the number of tubercles on the opposable margins of the dactyl and propodus. This formula does not include the corneous distal tip of either the dactyl or propodus. The formula is derived by counting the number of denticles on distal edge of the dactyl and propodus (see example in Fig. 1). Generally, if this area is blade-like then a zero is noted. The first set of denticles is usually a series of very small tubercles that slightly increase in size. These denticles can be in several rows on the dactyl. The denticles are reported as Arabic numbers. A small triangular, corneous canine-like tooth is often the first denticle found on the propodus. We denote this triangular tooth with a lower case Roman numeral series. Generally, the mid-point of both the dactyl and propodus has a large, spherical to oval, tubercle that is the largest in the series. We denote this tubercle by an upper case Roman numeral. Finally, the tubercles that are proximal to the palm are denoted by Arabic numbers. Using this convention provides a methodology to differentiate between corneous, triangular tubercles, denticles, and large tubercles. We have found these tubercle characters to be consistent and diagnostic of crayfish species in both Orconectes and Cambarus genera (T.P. Simon unpubl, data).

[FIGURE 1 OMITTED]

Orconectes (Procericambarus) theaphionensis new species Sinkhole Crayfish

Figs. 2, 3-12; Table 1

Cambarus rusticus.--Girard 1852:8; Faxon 1885: 108, p1. 9: figs. 8, 8', 8a, 8a' [in part]; Hay 1891: 149 [in part].

Cambarus (Faxonius) rusticus.--Ortmann 1905: 112 [in part]; Ortmann 1931:82 [in part]; Eberly 1955:182 [in part].

Faxonius (Faxonius) rusticus.--Creaser 1933:21 [in part].

Orconectus rusticus.--Dubois & Sharma 1977:27 [in part].

Procambarus rusticus.--Huner 1978:4 [in part].

Orconectes (Procericambarus) rusticus.--Hobbs 1972:92 figs. 74c, 75b,d; 1974:40, fig. 136 [in part]; Fitzpatrick 1987:58 [in part]; Hobbs 1989: 49 [in part]; Page & Mottesi 1995:109 [in part]; Taylor 2000:138 [distribution map]; Simon 2001 : 107 [in part].

[FIGURES 2-12 OMITTED]

Etymology.--The species is named for the sulphur springs that are prevalent in the study area. Greek theaphion--of sulphur and brimestone. The vernacular name, sinkhole crayfish, refers to the Lost River watershed, perhaps among the largest cave systems in Indiana and North America.

Diagnosis.--Body and eyes pigmented. Rostrum concave dorsally, terminating in upturned acumen, median carina strong. Rostral margins thickened; edges distally converging providing a slightly convex appearance; terminating in lateral spines. Areola 29.0-40.2% ([bar.x] = 34.2, n = 100, SD = 1.63) of total length of carapace, narrowest part at midpoint, 12.4-39.4% ([bar.x] = 21.6, n = 100, SD = 5.11) times as long as wide with 3-5 punctations (mode = 4, n = 100, SD = 0.58). One corneous hepatic spine on each side of carapace. Postorbital ridges well-developed, terminating in slightly upturned corneous spines. Suborbital angle obsolete. Antennal scale broadest at midlength, thickened lateral margin terminating in large corneous spine. Ischia of third pereiopods of males with hooks: hooks over reaching basioischial articulation in form I males only. Chela with 2-3 rows of tubercles along mesial margin of palm, usually 6-10 tubercles in mesial most row, 4-8 in dorsomesial row, and occasionally present are a proximalmesial row of 3-9 weakly developed tubercles running to knob at base of dactyl; small tufts of setae on mesial margin of palm, dorsomesial and dorsolateral surfaces, and fingers; dorsal surfaces of fingers with well-developed longitudinal ridges. First pleopods of form i male symmetrical, extending to just past anterior edge of bases of second pereiopods when abdomen flexed. First pleopod of form I male with well-developed shoulder on cephalic surface at base of central projection; without strong 90[degrees] central projection comeous, constituting 34.4-56.3% ([bar.x] = 44.86%, n = 50, SD = 5.47) of total length of first pleopod, straight and tapering to a pointed tip; mesial process non-corneous and straight, distal end dorsally compressed and tapering to acute tip (see Variation), slightly subequal in length to central projection. First pleopod of form Il male noncorneous, extending to anterior edge of bases of second pereiopods when abdomen flexed; central projection straight, mesial process divergent from central projection, straight and subequal in length; both elements tapering to rounded tips. Annulus ventralus immovable, subcircular; cephalic half with wide median trough and two caudally-directed protuberances overhanging centrally located fossa; sinuate sinus running from center of fossa to caudal edge.

Description of holotypic male, form I.--Body slightly depressed dorsoventrally, carapace wider than abdomen (16.3 and 14.4 mm, respectively). Greatest width of carapace larger than height at caudodorsal margin of cervical groove (16.3 and 11.5 mm, respectively). Postorbital carapace length (26.3 mm) 79.2% of length of carapace. Areola 20.9 times longer (11.5 mm) than wide (2.4 mm) with four punctations across narrowest part; length of areola 34.5% of total length of carapace. Rostrum densely covered with punctations, excavated, strong median carina present; margins thickened, distal halves straight and slightly converging, terminating in rounded corneous spines, proximal halves slightly convex. Acumen terminating in upturned corneous spine and reaching just distal of midpoint of antennular peduncle. Postorbital ridges well-developed, terminating in slightly upturned corneous spines. Suborbital angle obsolete. Cervical spines corneous; branchiostegal areas of carapace smooth to slightly granular, dorsal surface with scattered punctations. Setae present posterior to the cervical groove and anterior area of the areola.

Carapace length nearly equal in length to abdomen (33.2 and 33.0 mm, respectively). Cephalic section of telson with two immovable spines in each caudolateral corner extending over exopodite. Caudal margin of cephalic section of exopodite with numerous fixed spines (21) and one large movable spine in caudolateral corner. Cephalic and caudal sections of exopodite with prominent median ridge. Lateral margin of endopodite terminating in spine; endopodite with prominent median ridge terminating in premarginal spine. Dorsal surface of telson and uropods setiferous. Antennal scale broadest at midlength, thickened lateral margin terminating in large corneous spine. Right antennal scale 7.02 mm long, 2.43 mm wide.

Mesial surface of palm of left chelae with three rows of tubercles, eight tubercles in mesial most row, seven tubercles in dorsomesial row, and three small widely interspersed tubercles lateral to dorsomesial row, six basiodactyl punctations form a weak row running to knob at base of dactyl. Mesial and lateral surfaces of chela covered with numerous setiferous punctations; ventral surface with scattered punctations. Dorsal surface of finger of propodus with submedian longitudinal ridges flanked by setiferous punctations; basal half of opposable margin with four small tubercles, a large prominent tubercle near midlength, five well-developed distal tubercles, and a small, triangular, corneous tubercle near distal edge (propodus tubercle formula: 0, 8, 1, 4). Dorsal and ventral surfaces of dactyl with submedian longitudinal ridges flanked by setiferous punctations; basal half of opposable margin with four well-developed tubercles, a large prominent tubercle at midlength, and eight distal tubercles in two interdigitated row (dactyl tubercle formula: 0, i, 5, I, 4). Finger of propodus and dactyl with rounded subterminal corueous tip.

Carpus with deep oblique furrow dorsally; mesial margin with a single large corneous procurved spine at midlength and three small corneous spines along distomesial margin; ventral surface with a single corneous spine just mesial to mid-length of distal margin, distoventrolateral corner enlarged and globular with a single small corneous spine overhang ing chelae. Dorsodistal surface of merus with three corueous spines; ventral surface with two large corneous spines and a single tubercle at midlength of ventrolateral margin and lateral to mesial row of seven spines, some corueous; row terminating in large corneous spine; small tubercle at distolateral corner. Ischium with a single tubercle just proximal to midlength of mesial margin and a single noncorueous spine on distal end of mesial margin.

Hook on ischium of third pereiopod only; hook simple, overreaching basioischial articulation and opposed by large rounded tubercle on basis. First pleopod as in Diagnosis above, central projection constituting 47.7% of total length of first pleopod.

Description of allotypic female.--Differing from holotype as follows. Areola constituting 32.1% of length of carapace and 3.8 times longer than wide. Postorbital carapace length 75.4% of length of carapace. Acumen with upturned corneous spine at distal tip. Mesial row of tubercles along palm of left chela with eight tubercles, dorsomesial row with seven, and distal dorsomesial row with three tubercles. Propodus with tuft of long setae at base of finger of opposable propodus with four well-developed tubercles proximal to palm, a prominent large tubercle at midlength, and five small distal tubercles in two interdigitated rows, with a single small, corneous, triangular, hooked tubercle at distal edge (propodus tubercle formula: 0, i, 5, I, 4). Opposable margin of dactyl with four well-developed tubercles, a single prominent tubercle at midlength, and five distal tubercles (dactyl tubercle formula: 0, 5, I, 4). Ventral surface of left merus with two corueous spines at midlength and lateral row of tubercles along mesial margin.

Sternum between third and fourth pereipods narrowly V-shaped. Postannular sclerite as wide as annulus ventralis. Annulus ventralis described in Diagnosis. First pleopods uniramous, barely reaching caudal margin of annulus when abdomen flexed.

Description of morphotypic male, form II.--Differing from holotype as follows. Areola constituting 33.9% of length of carapace and 6.4 times longer than wide. Postorbital carapace length 73.7% of length of carapace. Acumen with upturned corneous spine at distal tip. Mesial row of tubercles along palm of left chela with eight tubercles, dorsomesial row with five tubercles, and distal dorsomesial row with five tubercles. Dorsodistal surface of left merus with two corneous spines. Ventral surface of left merus with a single corneous spine and another single tubercle at midlength and lateral to row of tubercles along mesial margin.

Hook on ischium of third pereiopod not overreaching basioischial articulation. First pleopod without well-developed divergent mesial projection, instead blunt and blade-shaped, as described in Diagnosis.

Size.--Largest specimen examined 39.2 mm total carapace length (CL) form I male. Females (n = 25) ranging in size from 22.8-36.4 mm CL. Form I males (n = 50) ranging from 21.4-39.2 mm CL. Form II males (n = 25) ranging in size from 19.4-36.5 mm CL.

Color.--Dorsal and lateral surfaces of cephalothorax, pereiopods, and tail fan light brown to olive green. Dorsum with one large laterally elongate dark brown patch just anterior to areola. Cephalothorax with dark brown dorsolateral U-shaped saddle connected at caudal margin and extending to just posterior of midlength of lateral surfaces. Dorsal surfaces of abdominal segments 1-5 with dark brown patches, patches forming solid dark brown bar running from posterior edge of carapace to fifth abdominal segment when abdomen extended. Lateral surfaces of abdominal segments light orange, followed laterally by dark brown patches at edges. Dorsal and lateral surfaces of chelae, carpus, and merus olive green; dorsal surface of chelae covered with small dark flecks. Fingers of chelae with orange tips, followed proximally by wide black bands. Ventral surfaces of chelae, cephalothorax, and abdomen cream to white.

Type locality.--Half Moon Springs at bridge at Indiana County Road 200 E, 2.57 km W of Chambersburg, Paoli Township, Orange County, Indiana; 38.5207348 [degree]N, 86.4229192 [degree]W. The holotype was collected from a riffle on limestone bedrock in midchannel, about 20 m upstream of the bridge. The allotype, morphotype, and paratypes were collected from cobble and slab bolder riffle habitats in close proximity to the holotype collection. At the time of collection, Half Moon Spring was 2.7 m wide with an average depth of 0.4 m. Substrate at the type locality was limestone bedrock with slab cobble and boulders. The stream is located in Hoosier National Forest and land use adjacent in the stream channel is pasture and forest.

Disposition of types.--The holotype, allotype, and morphotype are deposited at the National Museum of Natural History, Smithsonian Institution, Washington, D.C. (USNM 1075206, USNM 1075207, and USNM 1075208, respectively). Paratypes consisting of 12[male]I, 30[male]II, 2juv[male]; 42[female], 7juv[female] (INBS 841) are deposited at the Indiana Biological Survey, Aquatic Research Center, Crustacean Collection, Bloomington, Indiana; paratypes 1[male]I, 1[male]II, and 1[female] (OSUMC 5972) are deposited at the Ohio State University Museum of Biodiversity, Columbus, Ohio; and paratypes 1[male]I, 1[male]II, and 1[female] (INHS 9552) are deposited at the Illinois Natural History Survey Crustacean Collection, Champaign, Illinois.

Range.--Orconectes theaphionensis new species, is found in the Lost River drainage, above and below the Orangeville Rise, including Stampers Creek and other sinkholes, and adjacent Blue Creek (East Fork White River drainage) in south central Indiana (Fig. 13). The Lost River originates in eastern Orange County flowing northeast for about 57.3 km before emptying into the East Fork White River. Stampers Creek is a disjunct stream channel that is connected to the Lost River through sinkhole connections. Blue Creek occurs directly west of the Lost River entering the East Fork White River near Shoals. Both watersheds drain interbedded limestones, sandstones, and shale deposits of middle Pennsylvanian age. The species may be present in Blue River (Harrison County; C.A. Taylor pers. commun.) and Indian Creek (Harrison County; TPS, unpubl, data); however, further genetic analysis of these two drainage forms may be necessary since our morphometric and pigmentation data suggest that they are new species.

[FIGURE 13 OMITTED)

A total of 1354 specimens has been examined from 42 locations in Indiana. Museum collection numbers and counties for these sites are listed in the Material Examined section, below.

Habitat and life-history notes.--Orconectes theaphionensis new species, occurs in creeks and small rivers with substrates of limestone bedrock, slab boulder and cobble rubble, and large gravel. The species is most commonly encountered along rock substrates in shallow riffle areas or among slowly-flowing runs.

Form I males have been collected in all months sampled March-October, and we have not sampled during November to January (Table 2). No males were collected during February. Juveniles have been collected in June and July. Ovigerous females were collected on 25 March 1999 and 18 May 2004. One 26.7 mm CL female was carrying 113 eggs that averaged 1.20 mm in diameter, whereas a 28.9 mm CL individual carried 121 eggs that averaged 1.18 mm in diameter.

Crayfish associates.--The following species were collected from habitat containing O. theaphionensis new species: Cambarus (Erebicambarus) tenebrosus Hay 1902 (formerly Cambarus (Erebicambarus) laevis Faxon 1914); and Orconectes (Trisellescens) immunis (Hagen 1870); Cambarus (Lacunicambarus) sp. "B"; Cambarus (Lacunicambarus) sp. "C"; Cambarus (Tubericambarus) sp. "A."

Variation.--Ontogenetic variation is observed in Orconectes theaphionensis new species, none of which shows any geographic patterns of distribution. Weakly developed granular tubercles are occasionally apparent on the branchiostegal area. The pleopod in most form II male individuals has a mesial process that tapers to a sharply pointed distal tip, but in some specimens the distal one-third is spatulate due to a dorsoventral compression of the process. The dactyl and propodus formulas show distinct patterns, but the largest individuals have slightly more tubercles, such as the holotype. The dactyl formula range is 4-8 (usually in two rows), I, 3-4 (rarely 5), while the propodus formula is, 0, i, 3-6, I, (rarely 2) 3-4. Some increase in carapace width was observed in populations from Sulphur Creek; however, we view this variability as an ecomorph due to the prevalent cool temperatures (< 17[degree]C year round). In many smaller individuals, the entire length of the rostral margin is straight.

Comparisons.--Orconectes theaphionensis new species, differs from all other members of the genus Orconectes by possessing a unique combination of form I male pleopod, mandible, rostral carina, and chelae characters (Table 3). Only O. theaphionensis has a slightly caudally-divergent central and mesial projection in form 1 males. The central projection to total length of pleopod (mean = 44.86%, range = 34.4-56.3%) is intermediate between Orconectes cristavarius and O. putnami (Taylor 2000). In addition to O. theaphionensis, within the subgenus Procericambarus, only O. luteus (Creaser 1933) has a deflected central projection, but O. theaphionensis lacks a deflected mesial projection as O. luteus. The mandible is unserrated, and the chelae has three rows of mesial tubercles. The new form differs from O. juvenilis and O. rusticus by the presence of the strong median carina, suborbital angle obsolete, a divergent central and mesial projection that is greater than 35% central projection length to total length of pleopod.

Relationships.--The form I male pleopod of O. theaphionensis is most similar in length and general shape to members of the subgenus Procericambarus, and we assign O. theaphionensis to that subgenus. Until either molecular or morphological data from O. theaphionensis can be included in a phylogenetic analysis, we refrain from inferring the position of O. theaphionensis within the subgenus. Material examined.--Number, sex, and form of specimens examined are in parentheses. Asterisks (*) denote samples from which specimens were obtained for the statistical analyses; females and form II males were limited to 25 specimens. Data for monthly sex ratios (Table 2) was from the data below and from monthly repeat visits to the type locality. Form I male is indicated by MI, MII = form II male by MII, F = female, and juv = juvenile. CR = County Road, SR State Road, N = North, S = South, E = East, W = West and combinations. Collector(s) names are abbreviated after first use. INBS = Indiana Biological Survey Crustacean Collection.

Orconectes theaphionensis

INDIANA: Martin County: Tributary to Big Creek, fire road, 4.8 km N Natchez, Halbert Twp, 38.64704 N, 86.70642 W, (Thomas P. Simon, Erin R. Lawrence, Stephanie L. Worden, Jake L. Burskey), 17 May 2004, (* 3 MI, 6 MII, 20 F), INBS 835. Big Creek, US 150 bridge, 1.3 km W Natchez, Halbert Twp, 38.61883 N, 86.72565 W, (TPS, ERL, SLW, JLB), 17 May 2004 (* 2 MI), INBS 836. Unnamed tributary Lost River, 1.0 km N on CR 191, 1.8 km N Roland, Halbert Twp, 38.60868 N, 86.68498 W, (TPS, SLW), 1 September 2004, (* 1 MI, 6 MII, 3 F), INBS 859. Unnamed tributary Lost River, CR 198 bridge, 3.7 km S Roland, Lost River Twp, 38.56330 N, 86.68717 W, (TPS), 12 July 2004, (* 2 MII, 8 E 65 juv), INBS 861. Unnamed tributary Lost River, CR 4 bridge, 3.5 km S Roland, Lost River Twp, 38.56534 N, 86.68970 W, (TPS), 12 July 2004, (5 juv), INBS 862. Unnamed tributary Lost River, CR 195 bridge, 1.0 km NNW Natchez, Halbert Twp, 38.62170 N, 86.72446 W, (TPS), 1 July 2004, (5 MI, 4 MII, 11 F), INBS 863. Blue Creek, CR 900 E bridge, 3.5 km SE Rusk, Lost River Twp, 38.53398 N, 86.74278 W, (TPS), 14 July 2004, (11 juv), INBS 864. Blue Creek, CR 5 bridge, 0.2 km N Yenne, Lost River Twp, 38.54859 N, 86.79698 W, (TPS, JLB), 12 July 2004, (6 MII, 2 F, 41 juv), INBS 865. Blue Creek, CR 37 bridge, 1.3 km W Yenne, Lost River Twp, 38.54683 N, 86.80775 W, (TPS, SLW), 1 September 2004, (11 *I, 36 MII, 37 F), INBS 866. Unnamed tributary Lost River, CR 177 bridge, 2.7 km SE Yenne, Lost River Twp, 38.53297 N, 86.76574 W, (TPS), 14 July 2004, (3 juv), INBS 867. Qualkenbush Spring, CR 7, 3.5 km WSW Natchez, Halbert Twp, 38.60410 N, 86.75406 W, (TPS, JLB, ERL, SLW), 1 July 2004, (*2 MI, *3 MII, *4 F), INBS 868. Orange County: Carters Creek, CR 650 E bridge, 3.2 km SE Leipsic, North East Twp, 38.64843 N, 86.33554 W, (TPS, Brant E. Fisher, Katherine Gremillion-Smith), 18 March 1999, (12 MI, 6 MII, 5 F), INBS 828. Lost River, CR 650 E bridge, 3.2 km N Bromer, North East Twp, 38.62109 N, 86.33545 W, (TPS, BEF, KGS), 18 March 1999, (19 MI, 3 MII, 12 F), INBS 829. Carters Creek, Sutter Lane bridge, 4.8 km ESE Leipsic, North East Twp, 38.65931 N, 86.30991 W, (TPS, BEE KGS), 18 March 1999, (7 MI, 1 MII, 10 F), INBS 830. Tributary to Halfmoon Springs, US 150 bridge, 3.2 km SE Paoli, Paoli Twp, 38.54503 N, 86.44936 W, (TPS, ERL), 16 June 2004, (1 MI, 1 F, 12 juv), INBS 833. Tributary to Halfmoon Springs, US 150 bridge, 0.3 km NW Chambersburg, Paoli Twp, 38.51769 N, 86.39197 W, (TPS, ERL, SLW, JLB), 17 June 2004, (*1 MI, 1 MII, 4 F), INBS 834. Stampers Creek, SR 56 bridge, 0.5 kin SE Millersburg, Stampers Creek Twp, 38.55731 N, 86.33351 W, (TPS), 21 June 2004, (2F), INBS 837. Stampers Creek, CR 500 E bridge, 2.6 km NE Millersburg, Stampers Creek Twp, 38.58821 N, 86.36446 W, (TPS, ERL, SLW, JLB), 21 June 2004, (19 MII, 29 F, 12 juv), INBS 838. Lick Creek, CR 350 S bridge, 2.6 km WSW Chambersburg, Paoli Twp, 38.50657 N, 86.41743 W, (TPS, SLW), 13 September 2004, (*l MI, 11 MII, 9 F, 3 juv), INBS 839. Halfmoon Springs, CR 200 E bridge, 5.2 km W Chambersburg, Paoli Twp, 38.52073 N, 86.42292 W, (TPS), 21 June 2004, (29 MII, 81 F, 31 juv), INBS 840. Unnamed tributary Lick Creek, Spring Mill Road bridge, 2.3 km WNW Chambersburg, Paoli Twp, 38.52488 N, 86.41997 W, (TPS, SLW), 13 September 2004, (*16 MI, *34 MII, *46 F, 9 juv), INBS 841. Willow Creek, CR 125 W, 4.8 km SSW Paoli, Paoli Twp, 38.50398 N, 86.45630 W, (TPS, SLW), 13 September 2004, (16 MI, 2 MII, 10 F), INBS 842. Lick Creek, S Elm Street bridge, 1.9 km W Paoli, Paoli Twp, 38.55585 N, 86.47484 W, (TPS), 24 June 2004, (2 MI, 18 MII, 22 F, 6 juv), INBS 843. Log Creek, Log Creek Road, 4.8 km SW Paoli, Paoli Twp, 38.54277 N, 86.52128 W, (TPS), 24 June 2004, (4 juv), INBS 844. Log Creek, Log Creek Road, 4.5 km W Paoli, Paoli Twp, 38.56097 N, 86.52625 W, (TPS, Anne E. Timm, JLB, ERL, SLW), 30 June 2004, (*13 MI, *26 MII, *53 F, 47 juv), INBS 845. Unnamed tributary Lick Creek, CR 500 W bridge, 6.1 mi NE West Baden Springs, Orangeville Twp, 38.59293 N, 86.55263 W, (TPS), 24 June 2004, (*10 MI, *21 MII, *22 F, 2 juv), INBS 846. Lick Creek, US 150 bridge, 2.7 km NE West Baden Springs, French Lick Twp, 38.5061 N, 86.57680 W, (TPS, SLW), 13 September 2004, (1 MI, 2 MII, 1 F), INBS 847. Upper Sulphur Creek, CR 100 S bridge, 4.0 km E French Lick, French Lick Twp, 38.54200 N, 86.56122 W, (TPS, JLB), 28 June 2004 (1 MI, 9 MII, 37 E 34 juv), INBS 848. Upper Sulphur Creek, Abydel Road bridge, 2.3 km E West Baden Springs, French Lick Twp, 38.57078 N, 86.58461 W, (TPS), 29 June 2004, (2 MI, 1 MII, 2 F), INBS 849. French Lick Creek, CR 410 S bridge, 6.3 km SSE French Lick, Jackson Twp, 38.49564 N, 86.60119 W, (TPS, ERL, SLW, JLB), 28 June 2004, (5 MII, 4 F, 4 juv), INBS 850. Unnamed tributary French Lick Creek, CR 625 W bridge, 5.5 km SE French Lick, French Lick Twp, 38.51430 N, 86.57527 W, (TPS), 28 June 2004 (4 MI, 13 MII, 24 F, 3 juv), INBS 851. French Lick Creek, SR 145 bridge, 6.1 km SSE French Lick, Jackson Twp, 38.49571 N, 86.60317 W, (TPS, SLW), 2 September 2004, (5 MI, 10 MII, 25 F), INBS 852. French Lick Creek, CR 300 S bridge, 4.3 km S French Lick, French Lick Twp, 38.51249 N, 86.61496 W, (TPS, ERL, JLB, SLW), 28 June 2004, (*1 MI, 9 MII, 13 E 5 juv), INBS 853. French Lick Creek, Old SR 145, 2.7 km S French Lick, French Lick Twp, 38.53062 N, 86.61094 W, (TPS, SLW), 2 September 2004, (4 MI, 1 MII, 11 F), INBS 854. Unnamed tributary French Lick Creek, CR 75 S bridge, 1.3 km SE French Lick, French Lick Twp, 38.54354 N, 86.60658 W, (TPS), 29 June 2004, (3 F), INBS 855. French Lick Creek, Sinclair Street bridge, 0.8 km W West Baden Springs, French Lick Twp, 38.56346 N, 86.60555 W, (TPS), 19 July 2004, (6 MII, 12 F), INBS 856. French Lick Creek, West Baden Springs Hotel driveway bridge, West Baden Springs, French Lick Twp, 38.56702 N, 86.61398 VC, (TPS), 19 July 2004, (5 MII, 3 F), INBS 857. Sulphur Creek, CR 500 N bridge, 2.6 km SSW Bonds, Northwest Twp, 38.62035 N, 86.63228 W, (TPS, AT, JLB, ERL, SLW), 30 June 2004, (4 MI, *21 MII, *10 F, 8 juv), INBS 858. Unnamed tributary Lost River, CR 1125 W bridge, 4.3 km W French Lick, French Lick Twp, 38.54475 N, 86.67119 W, (TPS), 12 July 2004, (4 MI, 5 MII, 10 F, 2 juv), INBS 860. Unnamed tributary Lost River, CR 425 N bridge, 2.6 km WSW Orangeville, Orangeville Twp, 38.62129 N, 86.58393 W, (TPS, JLB, ERL, SLW), 29 June 2004, (1 MI, 13 juv), INBS 869. Washington County: Lost River, Vernon School Road bridge, 2 mi SE Claysville, Vernon Twp, 38.59304 N, 86.27104 W, (TPS, BEF, KGS), 18 March 1999, (2 MI, 1 MII, 3 F), INBS 831. Lost River (including unnamed tributary mouth), Satillo-Livonia Road bridge, 2.5 mi NW Livonia, Vernon Twp, 38.59349 N, 86.29107 W, (TPS, BEF, KGS), 18 March 1999, (4 F), INBS 832.

ACKNOWLEDGMENTS

The authors appreciate field assistance from S.L. Worden, J.L. Burskey, E.R. Lawrence, K. Gremillion-Smith, and B.E. Fisher. We thank C.A. Taylor, INHS, and R.F. Thoma (OSU) for assistance and professional courtesies. R.E Thoma provided an initial review of this manuscript and two anonymous reviewers improved the submitted manuscript. We appreciate the assistance of K. Reed and G. Keel for providing records from the USNM and collection number assignments for type specimens, R.F. Thoma (OSUMC), and C.A. Taylor (INHS) provided collection number assignments for paratypes from their respective institutions. We are grateful to S.L. Worden (INBS) for preparing the specimen examined list. Line drawn illustrations in Figs. 3-12 were prepared by B. Simon, the color photograph in Fig. 2 was taken by TPS, and CCM prepared the map in Fig. 13. No opinions, expressed or implied, should be considered an endorsement by the U.S. Forest Service. This study was funded by U.S. Forest Service grant NF1M012559-0912 to TPS.

Manuscript received 20 May 2005, revised 10 June 2005.

LITERATURE CITED

Bouchard, R.W. 1976. Geography and ecology of crayfishes of the Cumberland Plateau and Cumberland Mountains, Kentucky, Virginia, Tennessee, Georgia, and Alabama, Part I: The genera Procambarus and Orconectes. Pp. 563-584, In (J.W. Avault, Jr., ed.), Freshwater Crayfish. Louisiana State University Division of Continuing Education, Baton Rouge, Louisiana.

Bundy, W.F. 1877. On the Cambari of northern Indiana. Proceedings of the Academy of Natural Sciences of Philadelphia 29:171-174.

Creaser, E.P. 1933. Descriptions of some new and poorly known species of North American crayfishes. Occasional Papers of the Museum of Zoology, University of Michigan 275. 21 pp., 2 p1.

Dubois, J. & M.L. Sharma. 1977. An investigation of the enzymes during degradation in the freshwater crayfish Orconectes rusticus, on acclimation to 50% seawater. Science Studies, St. Bonaventure University 32:27-34.

Eberly, W.R. 1955. Summary of the distribution of Indiana crayfishes, including new state and county records. Proceedings of the Indiana Academy of Science 64:281-283.

Faxon, W. 1884. Descriptions of new species of Cambarus, to which is added a synonymical list of the known species of Cambarus and Astacus. Proceedings of the American Academy of Sciences 20: 107-158.

Faxon, W. 1885. A revision of the Astacidae, Part I: The genera Cambarus and Astacus. Memoirs of the Museum of Comparative Zoology at Harvard College 10:i-vi, 1-186.

Faxon, W. 1914. Notes on the crayfishes in the United States National Museum and the Museum of Comparative Zoology with descriptions of new species and subspecies to which is appended a catalogue of the known species and subspecies. Memoirs of the Museum of Comparative Zoology at Harvard College 40(8):351-427, 13 pl.

Fitzpatrick, Jr., J.F. 1987. The subgenera of the crawfish genus Orconectes (Decapoda: Cambaridae). Proceedings of the Biological Society of Washington 100:44-74.

Girard, C. 1852. A revision of the North American Astaci, with observations on their habits and geographical distributions. Proceedings of the Academy of Natural Sciences of Philadelphia 6: 87-91.

Hagen, H.A. 1870. Monograph of the North American Astacidae. In Illustrated Catalogue of the Museum of Comparative Zoology at Harvard College 3:viii + 109 pp., 11 p1.

Hay, W.P. 1891. The crustacean fauna of Indiana. Proceedings of the Indiana Academy of Science 1891:147-150.

Hay, W.P. 1902. Observations on the crustacean fauna of Nickajack Cave, Tennessee, and vicinity. Proceedings of the United States National Museum 25:417-439.

Hobbs, H.H., Jr. 1972. Crayfishes (Astacidae) of North and Middle America. Biota of Freshwater Ecosystems, Identification Manual 9. United States Environmental Protection Agency. Pp. ix, 1-173.

Hobbs, H.H., Jr. 1974. A checklist of the North and Middle American crayfishes (Decapoda: Astacidae and Cambaridae). Smithsonian Contributions to Zoology 166:1-166.

Hobbs, H.H., Jr. 1989. An illustrated checklist of the American crayfishes (Decapoda: Astacidae, Cambaridae, and Parastacidae). Smithsonian Contributions to Zoology 480:1-236.

Huner, J.B. 1978. Exploitation of freshwater crayfishes in North America. Fisheries 3(6):2-5.

Ortmann, A.E. 1905. The mutual affinities of the species of the genus Cambarus, and their dispersal over the United States. Proceedings of the American Philosophical Society 44:91-136.

Ortmann, A.E. 1931. Crawfishes of the southern Appalachians and the Cumberland Plateau. Annals of the Carnegie Museum 20:61-160.

Page, L.M. & G.B. Mottesi. 1995. The distribution and status of the Indiana crayfish, Orconectes indianensis, with comments on the crayfishes of Indiana. Proceedings of the Indiana Academy of Science 104:103-111.

Simon, T.P. 2001. Checklist of the crayfish and freshwater shrimp (Decapoda) of Indiana. Proceedings of the Indiana Academy of Science 110:104-110.

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Thomas P. Simon (1), Anne E. Timm (2), and Charles C. Morris (1): (1)Aquatic Research Center, Indiana Biological Survey, 6440 South Fairfax Road, Bloomington, Indiana 47401 USA; (2) Hoosier National Forest, U.S. Forest Service, 248 15th Street, Tell City, Indiana 47586 USA

Table 1.--Measurements (mm) of Orconectes theaphionensis new species.

                                  Holotype   Allotype   Morphotype

Carapace:
  Total length                      33.2       36.4        28.3
  Postorbital length                26.3       27.5        20.9
  Width                             16.3       18.3        14.4
  Height                            15.4       18.1        11.6

Areola:
  Width                              2.4        3.1         1.5
  Length                            11.5       11.7         9.6

Rostrum:
  Width                              3.5        4.1         3.0
  Length                             6.9        9.0         7.4

Chela, right:
  Length, mesial margin of palm     10.1        7.3         7.0
  Palm width                        16.1       11.5         8.6
  Length, lateral margin            35.9       24.6        21.9
  Dactyl length                     17.8       11.4         9.4

Abdomen:
  Width                             14.4       17.2        11.9
  Length                            33.0       37.3        29.6

Table 2.--Seasonal data showing by month numbers
of individuals of each sex including sex ratios
for Orconectes (Procericambarus) theaphionensis,
new species. (a) = Female with eggs collected during
this month, (b) = Female with eggs and young collected
during this month.

            Male   Male               Sex
             I      II    Females    ratio

February       0      0     4           --
March          8      2    16 (a)    1/1.6
April          3      0    18       0.17/1
May          138     46   214 (b)    1/2.5
June          44    178   334        1/1.5
July          12     31    50       1/1.16
August         4     12    23        1/1.4
September     55     43   142        1/1.4
October      118     23   211        1/1.5

Table 3.--Comparison of characters diagnostic for Orconectes
(Procericambarus) theaphionensis new species for differentiation
from other Procericambarus species. TLP = total length of pleopod,
mean value reported with range of values in parentheses. n = number
of individuals examined for each species.

                          Orconectes               Orconectes
                          theaphionensis           juvenilis
Characters                (n = 100)                (n = 134)

Carina                    strong                   absent
Mandible incisor          non-serrate              non-serrate
Cervical groove setae     present                  absent
Mesial palm tubercles     2-3 rows                 2 rows
  mesial tubercles        6-10                     6-11
  dorsomesial             4-8                      7-11
  proximal mesial         3-9
                          44.9%                    48.3%
Central projection
    length: TLP           (34.4-56.3%)             (41.2-52.3%)
Chelae tubercle formula
  dactyl                  0, 4-8, I, 3-4 (5)       0, 4-5, III, 4
  propodus                0, i, 3-6, I, (2) 3-4    0-2, i, 5, I-III, 2

                          Orconectes               Orconectes
                          rusticus                 cristavarius
Characters                (n = 68)                 (n = 180)

Carina                    absent                   present
Mandible incisor          non-serrate              serrate
Cervical groove setae     absent                   absent
Mesial palm tubercles     2 rows                   2 rows
  mesial tubercles        6-I1                     7-11
  dorsomesial             7-12                     5-10
  proximal mesial
                          41.7%                    47.0%
Central projection
    length: TLP           (35.7-46.5%)             (40.0-52.0%)
Chelae tubercle formula
  dactyl                  0, 10-16                 0, 1-2, I, 4-5
  propodus                8-13, i, 3-4, I, 2-4     0,-, 1-2, I, 3-4

                          Orconectes               Orconectes
                          putnami                  ronaldi
Characters                (n = 43)                 (n = 81)

Carina                    absent                   absent
Mandible incisor          serrate                  serrate
Cervical groove setae     absent                   absent
Mesial palm tubercles     2 rows                   2 rows
  mesial tubercles        9-10                     7-9
  dorsomesial             8-10                     6-8
  proximal mesial
                          53.1%                    45.0%
Central projection
    length: TLP           (48.4-57.0%)             (41.0-49.0%)
Chelae tubercle formula
  dactyl                  0, 7-8, III-IV, 3-4      0, 3-4, I, 5-6
  propodus                3-4, i, 3-4, III-IV, 2   0, i, 3-4, I, 5-6