Notropis mekistocholas, a New Herbivorous Cyprinid Fish ~ndernic to the Cape Fear River Basin, North Carolina FRA1"lKLIN F. SNELSON, JR. Notropis mekistocholas is described as a new species. It is unusual within the genus in exhibiting herbivorous adaptations-an elongate, convoluted intestine and black peritoneum. It is compared with N. alborus and N. procne, two sympatric relatives that differ in lacking herbivorous modifications, in hav.ing seven rather than eight anal rays, and in numerous other features. N. mekistocholas is the first known endemic species from the Cape Fear drainage in North Carolina. It has a very restricted distribution in the east-central Piedmont province, being known from only four streams in Chatham and Harnett counties. Intestinal modifications suggestive of an herbivorous diet are reported for N. anogenus and some species of the subgenus Luxilus. There is no evidence to suggest that N. mekistocholas should be aligned with the south. western genus Dionda, which contains herbivorous species superifically similar to Notropis species. Closest relatives of N. mekistocholas appear to be N. procne and N. stramineus. INTRODUCTION The number of predorsal scale rows in- HE genus NotroPis usually has been char. cludes all oblique scale rows crossing an imaginary line between the anterior inser- T acterized as having a short, S-shaped ali- mentary tract, distinguishing it from closely tion of the dorsal fin and the cleithrum. The related groups containing herbivorous forms first row counted was the one including the with elongate intestines. Discovery of a first predorsal scale; the last row counted was unique new species of Notropis, closely re- the one including the first (anterior-most) lated to N. procne (Cope), with an elongate lateral line scale. Single scales interposed be- gut tends to obscure further the already- tween two otherwise regular rows were not vague limits of certain North American counted. However, two or more scales in a cyprinid genera. regular oblique series were considered a row even if that series terminated before. cross- This new minnow was first discovered in ing the dorsal midline or the lateral line. 1962 in a poorly collected region of the Cape Fear River drainage in east-central North The breast was defined as that triangular- Carolina. Subsequent collecting has revealed shaped area forward of an imaginary line that it is endemic to avery restricted area joining the most posterior point of the bases within that system. Although its situation of the pectoral fins. Extent of breast scala- tion was estimated to the nearest 5%. Height at present is not precarious, its limited dis- and width of the exposed portion of the third tribution and the constant threat of habitat lateral line scale behind the head were de- alteration suggest that this new form should termined under a dissecting microscope be added to the growing list of endangered equipped with an ocular micrometer; the species. results were expressed in a height.to.width ratio. Gill rakers on the lower limb of the METHODS first branchial arch were enumerated on the Counting and measuring procedures fol- right side for ease of handling. Any raker lowed Hubbs and Lagler (1958:19-26) ex- that straddled the angle of the arch was in. cept as noted. Expression of meristic data cluded in the count. Vertebral numbers in the form (8)9-11 (13) indicates that ex- were determined from radiographs. The treme values for this character were 8 and Weberian apparatus was included as four 13, and that 85-95% of the observed counts and the hypural as one. were between 9 and 11. The opercular membrane was excluded 449 450 COPEIA, 1971, NO.3 Fig. 1. A and B. Lateral and dorsal views of Notropis mekistocholas, gravid adult female 45.4 mm SL, NCSM 3105. C and D. Lateral and dorsal views of NotroPis procne, tuberculate adult male 47.2 mm SL, NCSM 2974. (The slightly deeper body of the N. mekistocholas specimen is due to enlarged ovaries.) from head length and postorbital head length plane. Body width was the maximum di- measurements. Fleshy orbit length was the mension, measured between the pectoral greatest transverse distance between the and pelvic fin bases. Distance between the fleshy margins of the orbit, excluding any dorsal fin origin and the occiput was mea- marginal skin that grew inward to cover the sured along the dorsal midline. Postdorsal cornea. Distance from the dorsal fin origin length was taken from the origin of the dor- to the lateral line was measured in a vertical sal fin to the caudal base. Prepelvic and SNELSON-NEW NOTROPIS 451 count of either canal. Unlike some recent authors (e.g. Reno, 1969), I follow Illick (1956) and include in the infraorbital canal those pores in the postocular commissure in addition to those in the infraorbital sensu stricto. N otroPis mekistocholas n. sp. Cape Fear Shiner B Figs. lA, B; 2A, B Apparently there are no references to this - - species in the literature. All of the material that Jordan (1889) recorded as N. procne from the Cape Fear has been reexamined by c Hubbs and Raney (1947) and myself and :.~,~,,:,:,"~-~~ found to represent either N. albarus or N. '. pracne. ) Holotype.-U.S. National Museum (USNM) 205299 (formerly NCSM 4928); a tUberculate ~~'. "-'~''''~;: adult male 55.7 mID SL; Cape Fear (Deep) dr., N. C., Chatham Co., Rocky R., N. C. D Hwy. 902 bridge, 7.0 air miles SW center - Pittsboro; 2 June 1968; Franklin F. Snelson, Jr. and William M. Palmer (FFS-68-31). - Paratypes.- Thirty-six specimens collected Fig. 2. A. Ventral view of the alimentary with the holotype are distributed as follows: tract of Notropis mekistocholas with ventral body Cornell University (CU) 64397 (7 speci- wall, viscera, and mesentaries removed. B. Ali- mens); Tulane University (TU) 63272 (7); mentary tract of N. mekistocholas, diagrammatic. University of Florida (UF) 17303 (7); Uni- C. Ventral view of the alimentary tract of NotroPis procne with ventral body wall, viscera, versity of Michigan Museum of Zoology and mesentaries removed. D. Alimentary tract (UMMZ) 197680 (7); USNM 205300 (8). of N. procne, diagrammatic. Anterior to the left. Other material.-None of the following are designated as type material: All were col- peranal measurements were taken from the lected in the Cape Fear drainage in North insertion of the first ray of those fins to the Carolina and are deposited in the North tip of the upper lip. The distance between Carolina State Natural History Museum. the anal fin origin and caudal fin base is NCSM 2078 (6 specimens); Harnett Co., self-explanatory. Neal's Cr., Co. Hwy. 1441 bridge, 2.5 miles In determining the length of the alimen- W Angier. NCSM 2770 (4), 2976 (30), tary tract, the gut was severed immediately 3105 (13), 4842 (13); Chatham Co., Robeson behind the transverse septum and at the Cr., Co. Hwy. 1939 bridge, 4.5 air miles ESE anus; and all the viscera were removed. Con- center Pittsboro. NCSM 3278 (16); Harnett nective tissue and organs were dissected Co., Parker's Cr., Co. Hwy. 1450 bridge, 7.5 away; and the alimentary tract was straight- air miles WSW Fuquay-Varina. NCSM 3463 ened, without stretching, along a steel milli- (17), 3707 (5); Chatham Co., Rocky R., Co. meter rule. Hwy. 1010 bridge, 5.5 miles SW center Pitts- Terminology, abbreviations, and counting boro. NCSM 3883 (15); Chatham Co., procedures for the cephalic lateral line fol- Rocky R., U. S. Hwy. 15-501 bridge, 6.75 low Illick (1956) with these exceptions: miles S Pittsboro. NCSM 4126 (29), 5281 1) The broad separation of the supratem- (32); Chatham Co., Rocky R., N. C. Hwy. poral canal at the dorsal midline is indicated 902 bridge, 5.5 air miles SW center Pittsboro. by a comma; otherwise, interruptions along A total of 276 specimens of the new species the length of a canal are indicated by a plus has been examined. (+) sign. 2) A common pore at the junction Diagnosis.-Distinguished from all mem- of the supratemporal canal and postocular bers of the genus in having an elongate ali- commissure was not included in the pore mentary tract with two accessory convo- 452 COPEIA, 1971, NO.3 OJ a> "'! ,~ '" ..,.. :c ;:: c-.i u OJ :: ~"" Q 0 Q .... z a> <C " ~ '";:: ..'" c ~ .c 0 -; = a: ,.!j <0 I~ <C '" :..; os ... i .... <.> "" '" '" Q Z '" -: ~ I/) Q ... z <C .... ..., .; ~ co ..,.. .... .... C'l '" '" 0'> '" '" is '"~ co ~ ;;i 0'> c ..,. C1J .. ..,.. z ... co -9.Q '" " "" I . 101 '" "" <:> :<!; ~ <:> ~ ~ ~ ..,.. I "," ~ ~ 0'1 <C 1 '" ..:; Q ..,.. 0> ... c z c>I <:> 0> 0'1 co <C "S:=- .... .... 00 c>I ..!. .... ~ ~ ... «> co :;;; -: <:> <:> C'l co ..,.. ~.... "" «> e ..:;'" .. ..!. " ~ :: en '" " ... ~'"t Q ~ OC') C'l <:> c c <C .... .. .~ a: '" ~ '".:; ..; 0; ... ~ '" «> «> «> <0 o~ "" 0;'" :<!; ~ co CC') " ... 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'"-: " :..;:..; :..; 1-< :..; :..; :..; :..; :..; :..; SNELSON-NEW NOTROPIS 453 TABLE 2. FREQUENCY DISTRIBUTIONS FOR SOME MERISTIC CHARACTERS OF Notropis mekistocholas, N.