Procambarus acutissimus (Girard 1852)

Procambarus (O.) acutissimus: 118

50. Procambarus (O.) acutus acutus: 17, 24, 45, 52, 53, 62, 81–83, 87, 99, 103, 109, 121, 124, 140, 143, 150, 157, 158

Procambarus (Ortmannicus) acutissimus (Girard)

Cambarus acutissimus Girard, 1852:91.—Hagen, 1870:7, 9, 37.—Faxon, 1885a: 11.—Fleming, 1939:299.—Hobbs, 1967a:124, 130;1972a:2.

Cambarus acutus [in part].—Hagen, 1870:9.—Some authors prior to 1942.

Cambarus Blandinigii var. acuta [in part].—Faxon, 1884:136; 1885a:20, 22.—Underwood, 1886:368.

Cambarus blandingii acutus [in part].—Faxon, 1914:413, followed by many authors prior to 1942.

Procambarus blandingii acutus [in part],—Hobbs, 1942b:94, and most authors from 1942 to 1955.

Procambarus acutissimus.—Hobbs, 1955a:98; 1959:890; 1962: 286, 288, fig. 51;1967a: 130, 131; 1968b:K-8, fig. 23e.—Hobbs and Walton, 1959:41; 1960b: 123, 128.—Fitzpatrick and Payne, 1968:20.—Hobbs III, 1969:21, 30, 41, tab. 3.—Hobbs and Hall, 1974:199—Hart and Hart, 1974:30, 87. 88, 90, 134.

Procambarus (Ortmannicus) acutissimus.—Hobbs, 1972a:9; 1972b:56, 150, 154, 155, figs. 21d, 46d; 1974b:53, fig. 246.—Bouchard, 1976c:14.

Procambarus acutissumus.—Hart and Hart, 1974:31 [erroneous spelling].

The references cited here constitute as near a complete bibliography of the species as I have been able to assemble. The lack of understanding of the species from 1870 to 1955, during which time there were no new records, misled authors during that period to follow Hagen's error in uniting Girard's Cambarus acutissimus and Cambarus acutus under the latter name.

SUMMARY OF LITERATURE.—The following brief description of this crayfish was offered by Girard, 1852: “Rostrum much more elongated than in any of the species of the same group; very much tapering and very acute, with slight indications of the lateral spines which are so well developed in C. Blandingii. The anterior abdominal pair of legs is terminated by a slender and recurved tip.” The specimens on which this description was based were taken “from an affluent of Mobile river in Kemper Co., Miss.,” and were received from D. C. Loyd, Esq. There is no statement as to how many specimens Girard had, and only two second form males that had been deposited in the Academy of Natural Sciences of Philadelphia were available to Hagen (1870). The latter erred on page 7 in transcribing Missouri for Mississippi in repeating Girard's locality, and on page 9 stated that “C. acutissimus is the second form of the male of C. acutus.” Referring to the “two young dry males” in the Academy of Natural Sciences, Hagen emphasized this opinion concerning their identity as follows: “There is no doubt that these males are the young of the species above described [Cambarus acutus], and I think also the veritable C. acutissimus Gir….”

Faxon (1884, 1885a), considering Girard's Cambarus acutus to be a varietal form of Cambarus Blandingii (Harlan, 1830), and following Hagen's treatment of C. acutissimus, placed the latter in synonomy with his Cambarus Blandingii var. acuta. Faxon, in turn, was followed by Underwood (1886). In his checklist of the crayfishes, Faxon (1914) elevated his variety to subspecific rank, using the combination Cambarus blandingii acutus and continued to consider C. acutissimus a junior synonym of it.

Hobbs (1955a:98) resurrected Girard's acutissimus, assigning it to the genus Procambarus, without comment and recorded the first specific locality for the species, “11.3 miles south of Macon on Route 45, Noxubee County, Mississippi.” Even though Hobbs (1962) illustrated the first pleopod of the species and noted that the range encompassed the Tombigbee, Alabama, and Choctawhatchee drainages in Alabama and Mississippi, he did not present a reason for separating his P. acutissimus from P. blandingii acutus until he (1967a: 130) stated:

The ‘paratypes’ [of Girard's C. acutissimus], however, which are still extant, and located in the Academy of Natural Sciences of Philadelphia, clearly indicate the necessity for recognizing C. acutissimus as a distinct species. It has subsequently been collected from a number of localities in eastern Mississippi and western Alabama….

The second specific locality cited for the species was that of Hobbs and Walton (1959): 18.8 miles east of Montgomery on Route 80, Macon County, Alabama, and Fitzpatrick and Payne (1968) noted that it had been found in the Sand Creek watershed in Oktibbeha County, Mississippi.

Hobbs III (1969) and Hart and Hart (1974) reported its occurrence in several localities in Alabama and Mississippi, where it served as host to some five species of entocytherid ostracods. Hobbs (1972b; 1974b) presented additional illustrations and defined its range. Hobbs and Hall (1974), in discussing siltation, reported that “tremendous populations occur in roadside ditches in which the water is so laden with finely divided particulate matter (principally clay particles) that a Secchi disk disappears at a depth of less than 5 cm below the surface.” Those references not mentioned add nothing to our knowledge of the species except in terms of opinions of its affinities with other crayfishes.

This species is first recorded from Georgia herein.

DIAGNOSIS.—Rostrum with or without marginal spines, tubercles, or angles at base of acumen, and lacking median carina. Carapace with or without 1 pair of cervical spines or tubercles. Areola 6.3 to 16.0 times as long as broad and constituting 29.7 to 35.4 percent of entire length of carapace (40.0 to 44.9 percent of postorbital carapace length). Antennal peduncle with well- developed spine, sometimes reduced to tubercle, on ischium. Ventral surface of basis and usually at least proximal half of ischium of third maxilliped with long plumose setae among simple stiff ones. Basis of cheliped without mesial spine. Mesial surface of palm of chela of male with row of 8 to 12 tubercles. Male with simple hooks on ischia of third and fourth pereiopods, both overreaching basioischial articulation, and that on fourth opposed by prominent tubercle on basis. First pleopods strongly asymmetrical and reaching coxae of third pereiopods; cephalic surface of neither member of pair with shoulder; subapical setae restricted to distal part of caudal knob; mesial process slender, often subspiculiform, and directed caudally to caudodistally and somewhat laterally; cephalic process corneous, acute, curved caudally almost at right angle to shaft of appendage, and somewhat hooding basal part of central projection; latter terminal element corneous, beaklike, situated between cephalic and caudal processes, and also directed caudally almost at right angle to shaft of appendage; caudal element consisting of caudal knob and caudal process; former subacute, located at cephalolateral base of central projection, its distal border studded with subapical setae, and basally continuous with lateral ridge on pleopod extending proximally for from one-fifth to half length of appendage; caudal process, situated on caudomedian extremity of shaft of appendage, mostly corneous, tapering to acute tip distally, not quite reaching apex of central projection; adventitious process lacking. Female with sternum anterior to annulus conspicuously multituberculate; annulus ventralis subspindle shaped, highly variable both in surface contour and in configuration of sinus, latter varying from single simple curve to 5-shaped: first pleopod present.

COLOR NOTES (Figure 136b).—Carapace brown dorsally, becoming suffused with red dorsolaterally and fading to pinkish tan or gray ventrally. Symmetrically arranged black spots occurring dorsally, 1 pair in hepatic region, and another at lateral junction of rami of cervical groove; branchiostegite with rather narrow longitudinal black stripe; posterior extremity of stripe joining submarginal one and coursing caudally from at least midlength of branchiostegite to and along anterior margin of caudal flange; pale pinkish gray to cream spots intermingled with dark tan ones scattered over most of lateral surface of carapace. Abdomen with broad dorsomedian, almost black stripe gently tapering caudally from first to sixth abdominal tergum; median stripe flanked by paired, narrower pink ones, and they, in turn, by yet narrower scalloped brownish to black stripe extending along bases of pleura; ventral parts of pleura mottled with tan and brown spots on pinkish background; telson and uropods also mottled with tan and brown on olive tan. Antennular and antennal peduncles and flagella olive brown, peduncles with black markings. Dorsal surface of distal 4 podomeres of third maxilliped olive tan. Cheliped tan to brown dorsally from distal part of ischium to yellowish apex of fingers; all podomeres with black tubercles and/or spines; lateral part of chela suffused with orange, and ventral surface more orange than tan. Remaining pereiopods olive brown dorsally from ischium distally, merus and carpus darker than other podomeres, and those of chela of second pereiopod paler than distal podomeres of other pereiopods.

TYPES.—ANSP 309 (2II).

TYPE-LOCALITY.—Affluent of Mobile River, Kemper County, Mississippi.

RANGE.—This crayfish is largely confined to the lower Piedmont and upper Coastal Plain provinces of Alabama and eastern Mississippi; a single locality for it occurs in the Fall Line Hills District of the Coastal Plain Province in Quitman County, Georgia. In Alabama, it is known from the following counties: Autauga, Bullock, Calhoun, Coffee, Dallas, Greene, Hale, Jefferson, Lowndes, Macon, Marengo, Montgomery, Perry, Pike, Shelby, Sumter, and Wilcox; in Mississippi, it has been collected in Clay, Kemper, Lauderdale, Noxubee, and Oktibbeha counties.

SPECIMENS EXAMINED.—Quitman County: pools and burrows along roadside adjacent to Pataula Creek, 4.2 mi W of Randolph Co line on US Hwy 82, 1I, 2, 3j, 4j, 17 Apr 1974, D. J. Peters, HHH, collectors. In addition, I have examined 634 specimens from Alabama and Mississippi collected in a number of localities in the counties listed under “Range.”

VARIATIONS.—With so few specimens available from Georgia, no conclusion can be drawn concerning the consistency of differences noted in the juveniles and adults, but the areola appears to be comparatively broader and shorter in the young. Over its entire range, this crayfish exhibits a rather striking array of variations, not only in features of the carapace but also in the secondary sexual characters. Although the name “acutissimus” was derived from the strongly acute rostrum of the specimens from Kemper County, Mississippi, that were available to Girard, the range of variability in the form of the rostrum in material from the Tombigbee-Mobile Basin in the county is rather striking (Figure 141 c,d. In specimens from farther upstream in Oktibbeha County (Figure 141 e,f), well-developed marginal spines are present. Postorbital and cervical spines are absent in most adult members from Kemper County, and those on the basis and ischium of the antennal peduncle are rudimentary at best; in contrast, all of these spines are well developed in representatives from Oktibbeha County. In their reduced spination, the Georgia specimens (Figure 141 a,b) more nearly resemble those from Kemper County. The first pleopods of those from the two Mississippi areas are much more similar to one another than is either to the pleopod of the Georgia male. The major differences lie in the disposition of the caudal process—which in specimens from Mississippi (Tombigbee Basin) are more elongate, extending much farther proximally than in crayfish from elsewhere in the range—and in the lateral surface of the pleopod. In males from the Tombigbee watershed (Figure 142f,l), there is a strong, comparatively sharp, straight ridge extending proximally from the caudal knob; in the material from the Choctawhatchee and Chattahoochee basins (Figure 142a,bg,h), the ridge is not so well defined and is arched cephalically. The mesial process of the pleopod in the specimen from Georgia is directed less strongly laterally (Figure 142g) than it is in those from other parts of the range and is deflected most in representatives of the Tombigbee populations (Figure 142k,l). As pointed out elsewhere, the annulus ventralis is highly variable, but those of the two females from Georgia resemble the annuli of specimens from the type-locality more closely than those of members of the species I have examined from elsewhere. The most conspicuous difference that seems to exist is in the surface contour of the annulus, which ranges from comparatively smooth with a ventromedian elevation to one that is irregular and equally as sculptured as that illustrated (Figure 139d.) The shape of the sinus varies from a simple are to consisting of two hairpin curves situated along the median line near midlength of the annulus.

SIZE.—Only three adult specimens have been collected in Georgia. The first form male has a carapace length of 32.3 (postorbital carapace length 25.6) mm; corresponding lengths of the two females are 34.8 (27.2) mm and 34.1 (26.8) mm.

Procambarus (Ortmannicus) acutissimus (Girard)

Cambarus acutissimus Girard, 1852:91.

Cambarus acutus [in part].—Many authors prior to 1942.

Cambarus blandingii acutus [in part].—Most authors prior to 1942.

Procambarus blandingii acutus [in part].—Most authors from 1942 to 1955.

Procambarus acutissimus.—Hobbs, 1942a:S42 [by implication]; 1955a:98; 1962a:286, fig. 51.

Procambarus (Ortmannicus) acutissimus.—Hobbs, 1972a:9.

TYPES.—ANSP 309 (2 II).

TYPE-LOCALITY.—Affluent of Mobile River, Kemper County, Mississippi.

RANGE.—Tombigbee, Alabama, and Choctawhatchee drainages in east-central Mississippi and west-central Alabama.

HABITAT.—Sluggish streams, ponds, and roadside ditches.

Procambarus (Ortmannicus) acutissimus (Girard)

Cambarus acutissimus Girard, 1852:91.

Cambarus acutus.—Most authors prior to 1942 [in part].

Procambarus blandingii acutus.—Most authors from 1942 to 1955 [in part].

Procambarus acutissimus.—Hobbs, 1955a:98; 1962a:286, fig. 51.

Procambarus (Ortmannicus) acutissimus.—Hobbs, 1972a:9; 1974b:53, fig. 246; 1981:366, figs. 15c, 136b, 138a, 139–142, 243.

Procambarus acutissumus.—Hart and Hart, 1974:31 [erroneous spelling].

TYPES.—ANSP 309 (2 male II). These specimens could not be located in 1980 or 1985.

TYPE LOCALITY.—Affluent (= tributary to Tombigbee River) of Mobile River, Kemper County, Mississippi.

RANGE.—Tombigbee River basin in Mississippi eastward to the middle Chattahoochee River basin in Georgia.

HABITAT.—Sluggish streams, ponds, and roadside ditches.